threads / patch / 50122

patch, 2 partsChange how HTTP response body is returned

Subject: [PATCH 1/2] Change how HTTP response body is returned

## tl;dr

29 messages between Dec 28, 2018 and Jan 10, 2019. Diffs are folded; open one to read it.

replies: 28people: 5as markdown or json

Masaya Suzuki· Dec 28, 2018, 01:47 UTC · lore

This changes the way HTTP response body is returned in http_request_reauth and post_rpc.

1. http_request_reauth makes up to two requests; one without a
   credential and one with a credential. The first request can fail if
   it needs a credential. When the keep_error option is specified, the
   response to the first request can be written to the HTTP response
   body destination. If the response body destination is a string
   buffer, it erases the buffer before making the second request. By
   introducing http_response_dest, it can handle the case that the
   destination is a file handle.
2. post_rpc makes an HTTP request and the response body is directly
   written to a file descriptor. This makes it check the HTTP status
   code before writing it, and do not write the response body if it's an
   error response. It's ok without this check now because post_rpc makes
   a request with CURLOPT_FAILONERROR, and libcurl won't call the
   callback if the response has an error status code.
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c        | 99 +++++++++++++++++++++++++++++----------------------
 remote-curl.c | 29 ++++++++++++---
 2 files changed, 81 insertions(+), 47 deletions(-)
Show changes to 2 files +81 −47

http.c, remote-curl.c

diff --git a/http.c b/http.c
index eacc2a75e..d23417670 100644
--- a/http.c
+++ b/http.c
@@ -165,6 +165,19 @@ static int http_schannel_check_revoke = 1;
  */
 static int http_schannel_use_ssl_cainfo;
 
+/*
+ * Where to store the result of http_request.
+ *
+ * At most one of buffer or file can be non-NULL. The buffer and file are not
+ * allocated by http_request, and the caller is responsible for releasing them.
+ */
+struct http_response_dest {
+	struct strbuf *buffer;
+
+	FILE *file;
+	const char *filename;
+};
+
 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 {
 	size_t size = eltsize * nmemb;
@@ -1794,12 +1807,8 @@ static void http_opt_request_remainder(CURL *curl, off_t pos)
 	curl_easy_setopt(curl, CURLOPT_RANGE, buf);
 }
 
-/* http_request() targets */
-#define HTTP_REQUEST_STRBUF	0
-#define HTTP_REQUEST_FILE	1
-
 static int http_request(const char *url,
-			void *result, int target,
+			struct http_response_dest *dest,
 			const struct http_get_options *options)
 {
 	struct active_request_slot *slot;
@@ -1812,21 +1821,23 @@ static int http_request(const char *url,
 	slot = get_active_slot();
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 
-	if (result == NULL) {
-		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
-	} else {
+	if (dest->file) {
+		off_t posn = ftello(dest->file);
 		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
-		curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
-
-		if (target == HTTP_REQUEST_FILE) {
-			off_t posn = ftello(result);
-			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
-					 fwrite);
-			if (posn > 0)
-				http_opt_request_remainder(slot->curl, posn);
-		} else
-			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
-					 fwrite_buffer);
+		curl_easy_setopt(slot->curl, CURLOPT_FILE,
+				 dest->file);
+		curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+				 fwrite);
+		if (posn > 0)
+			http_opt_request_remainder(slot->curl, posn);
+	} else if (dest->buffer) {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+		curl_easy_setopt(slot->curl, CURLOPT_FILE,
+				 dest->buffer);
+		curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+				 fwrite_buffer);
+	} else {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
 	}
 
 	accept_language = get_accept_language();
@@ -1930,10 +1941,10 @@ static int update_url_from_redirect(struct strbuf *base,
 }
 
 static int http_request_reauth(const char *url,
-			       void *result, int target,
+			       struct http_response_dest *dest,
 			       struct http_get_options *options)
 {
-	int ret = http_request(url, result, target, options);
+	int ret = http_request(url, dest, options);
 
 	if (ret != HTTP_OK && ret != HTTP_REAUTH)
 		return ret;
@@ -1949,32 +1960,34 @@ static int http_request_reauth(const char *url,
 	if (ret != HTTP_REAUTH)
 		return ret;
 
-	/*
-	 * If we are using KEEP_ERROR, the previous request may have
-	 * put cruft into our output stream; we should clear it out before
-	 * making our next request. We only know how to do this for
-	 * the strbuf case, but that is enough to satisfy current callers.
-	 */
-	if (options && options->keep_error) {
-		switch (target) {
-		case HTTP_REQUEST_STRBUF:
-			strbuf_reset(result);
-			break;
-		default:
-			BUG("HTTP_KEEP_ERROR is only supported with strbufs");
+	if (dest->file) {
+		/*
+		 * At this point, the file contains the response body of the
+		 * previous request. We need to truncate the file.
+		 */
+		FILE *new_file = freopen(dest->filename, "w", dest->file);
+		if (new_file == NULL) {
+			error("Unable to open local file %s", dest->filename);
+			return HTTP_ERROR;
 		}
+		dest->file = new_file;
+	} else if (dest->buffer) {
+		strbuf_reset(dest->buffer);
 	}
 
 	credential_fill(&http_auth);
 
-	return http_request(url, result, target, options);
+	return http_request(url, dest, options);
 }
 
 int http_get_strbuf(const char *url,
-		    struct strbuf *result,
+		    struct strbuf *dest_buffer,
 		    struct http_get_options *options)
 {
-	return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
+	struct http_response_dest dest;
+	dest.file = NULL;
+	dest.buffer = dest_buffer;
+	return http_request_reauth(url, &dest, options);
 }
 
 /*
@@ -1988,18 +2001,20 @@ static int http_get_file(const char *url, const char *filename,
 {
 	int ret;
 	struct strbuf tmpfile = STRBUF_INIT;
-	FILE *result;
+	struct http_response_dest dest;
 
 	strbuf_addf(&tmpfile, "%s.temp", filename);
-	result = fopen(tmpfile.buf, "a");
-	if (!result) {
+	dest.buffer = NULL;
+	dest.file = fopen(tmpfile.buf, "a");
+	if (!dest.file) {
 		error("Unable to open local file %s", tmpfile.buf);
 		ret = HTTP_ERROR;
 		goto cleanup;
 	}
+	dest.filename = tmpfile.buf;
 
-	ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
-	fclose(result);
+	ret = http_request_reauth(url, &dest, options);
+	fclose(dest.file);
 
 	if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
 		ret = HTTP_ERROR;
diff --git a/remote-curl.c b/remote-curl.c
index 1220dffcd..48656bf18 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -546,14 +546,31 @@ static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
 }
 #endif
 
+struct rpc_in_data {
+	struct rpc_state *rpc;
+	struct active_request_slot *slot;
+};
+
+/*
+ * A callback for CURLOPT_WRITEFUNCTION. The return value is the bytes consumed
+ * from ptr.
+ */
 static size_t rpc_in(char *ptr, size_t eltsize,
 		size_t nmemb, void *buffer_)
 {
 	size_t size = eltsize * nmemb;
-	struct rpc_state *rpc = buffer_;
+	struct rpc_in_data *data = buffer_;
+	long response_code;
+
+	if (curl_easy_getinfo(data->slot->curl, CURLINFO_RESPONSE_CODE,
+			      &response_code) != CURLE_OK)
+		return size;
+	if (response_code != 200)
+		return size;
+
 	if (size)
-		rpc->any_written = 1;
-	write_or_die(rpc->in, ptr, size);
+		data->rpc->any_written = 1;
+	write_or_die(data->rpc->in, ptr, size);
 	return size;
 }
 
@@ -633,6 +650,7 @@ static int post_rpc(struct rpc_state *rpc)
 	size_t gzip_size = 0;
 	int err, large_request = 0;
 	int needs_100_continue = 0;
+	struct rpc_in_data rpc_in_data;
 
 	/* Try to load the entire request, if we can fit it into the
 	 * allocated buffer space we can use HTTP/1.0 and avoid the
@@ -765,8 +783,9 @@ static int post_rpc(struct rpc_state *rpc)
 
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
-
+	rpc_in_data.rpc = rpc;
+	rpc_in_data.slot = slot;
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
 
 	rpc->any_written = 0;
 	err = run_slot(slot, NULL);
-- 
2.20.1.415.g653613c723-goog
Masaya Suzuki· Dec 28, 2018, 01:47 UTC · re: Masaya Suzuki · lore

[PATCH 2/2] Unset CURLOPT_FAILONERROR

When GIT_CURL_VERBOSE is set, libcurl produces request/response headers to stderr. However, if the response is an error response and CURLOPT_FAILONERROR is set, libcurl stops parsing the response, and it won't ump the headers. Showing HTTP response headers is useful for debugging, especially for non-OK responses.

This is substantially same as setting http_options.keep_error to all requests. Hence, removing this option.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c                       |  4 ----
 http.h                       |  1 -
 remote-curl.c                |  1 -
 t/lib-httpd/apache.conf      |  1 +
 t/t5581-http-curl-verbose.sh | 32 ++++++++++++++++++++++++++++++++
 5 files changed, 33 insertions(+), 6 deletions(-)
 create mode 100755 t/t5581-http-curl-verbose.sh
Show changes to 5 files +33 −6

http.c, http.h, remote-curl.c, t/lib-httpd/apache.conf, t/t5581-http-curl-verbose.sh

diff --git a/http.c b/http.c
index d23417670..8f8101da3 100644
--- a/http.c
+++ b/http.c
@@ -1269,7 +1269,6 @@ struct active_request_slot *get_active_slot(void)
 	curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
-	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 	curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
 
 	/*
@@ -1848,8 +1847,6 @@ static int http_request(const char *url,
 	strbuf_addstr(&buf, "Pragma:");
 	if (options && options->no_cache)
 		strbuf_addstr(&buf, " no-cache");
-	if (options && options->keep_error)
-		curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 	if (options && options->initial_request &&
 	    http_follow_config == HTTP_FOLLOW_INITIAL)
 		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
@@ -2415,7 +2412,6 @@ struct http_object_request *new_http_object_request(const char *base_url,
 	freq->slot = get_active_slot();
 
 	curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
-	curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
 	curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 	curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
 	curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
diff --git a/http.h b/http.h
index d305ca1dc..eebf40688 100644
--- a/http.h
+++ b/http.h
@@ -146,7 +146,6 @@ extern char *get_remote_object_url(const char *url, const char *hex,
 /* Options for http_get_*() */
 struct http_get_options {
 	unsigned no_cache:1,
-		 keep_error:1,
 		 initial_request:1;
 
 	/* If non-NULL, returns the content-type of the response. */
diff --git a/remote-curl.c b/remote-curl.c
index 48656bf18..43e7a1d80 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -380,7 +380,6 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
-	http_options.keep_error = 1;
 
 	http_ret = http_get_strbuf(refs_url.buf, &buffer, &http_options);
 	switch (http_ret) {
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 581c010d8..cc4b87507 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -115,6 +115,7 @@ Alias /auth/dumb/ www/auth/dumb/
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
 </LocationMatch>
+ScriptAliasMatch /error_git_upload_pack/(.*)/git-upload-pack error.sh/
 ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
 ScriptAlias /broken_smart/ broken-smart-http.sh/
 ScriptAlias /error/ error.sh/
diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
new file mode 100755
index 000000000..c89e06e12
--- /dev/null
+++ b/t/t5581-http-curl-verbose.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+test_description='test GIT_CURL_VERBOSE'
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'setup repository' '
+	git config push.default matching &&
+	echo content >file &&
+	git add file &&
+	git commit -m one
+'
+
+test_expect_success 'create http-accessible bare repository' '
+	mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	(cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	 git --bare init
+	) &&
+	git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git push public master:master
+'
+
+test_expect_success 'failure in git-upload-pack is shown' '
+	(GIT_CURL_VERBOSE=1 git clone --bare "$HTTPD_URL/error_git_upload_pack/smart/repo.git" 2>curl_log ||
+	 true) &&
+	cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
+'
+
+stop_httpd
+
+test_done
-- 
2.20.1.415.g653613c723-goog
Eric Sunshine· Dec 28, 2018, 19:36 UTC · re: Masaya Suzuki · lore

Re: [PATCH 2/2] Unset CURLOPT_FAILONERROR

On Thu, Dec 27, 2018 at 8:47 PM Masaya Suzuki <masayasuzuki@google.com> wrote:
> When GIT_CURL_VERBOSE is set, libcurl produces request/response headers
> to stderr. However, if the response is an error response and
> CURLOPT_FAILONERROR is set, libcurl stops parsing the response, and it
> won't ump the headers. Showing HTTP response headers is useful for
s/ump/dump/
> debugging, especially for non-OK responses.
>
> This is substantially same as setting http_options.keep_error to all
> requests. Hence, removing this option.
s/removing/remove/
Show 9 quoted lines
> Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
> ---
> diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
> @@ -0,0 +1,32 @@
> +test_expect_success 'setup repository' '
> +       ...
> +'
> +
> +test_expect_success 'create http-accessible bare repository' '

Not a big deal, but this seems like more setup, so it could be folded into the "setup" test above it.

> +       mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
> +       (cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
> +        git --bare init
> +       ) &&

Since this is a new test script, it makes sense to format the subshell in the modern style:

    (
        cd ... &&
        git ...
    ) &&
Alternately, use -C and drop the subshell altogether:
    git -C $BLAH/repo.git --bare init &&
Show 7 quoted lines
> +       git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
> +       git push public master:master
> +'
> +
> +test_expect_success 'failure in git-upload-pack is shown' '
> +       (GIT_CURL_VERBOSE=1 git clone --bare "$HTTPD_URL/error_git_upload_pack/smart/repo.git" 2>curl_log ||
> +        true) &&
Using test_might_fail() would allow you to drop the subshell and the "|| true":
    test_might_fail env GIT_CURL_VERBOSE=1  git clone ... &&
> +       cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
> +'
Masaya Suzuki· Dec 28, 2018, 19:51 UTC · re: Eric Sunshine · lore

Re: [PATCH 2/2] Unset CURLOPT_FAILONERROR

On Fri, Dec 28, 2018 at 11:37 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
Show 60 quoted lines
>
> On Thu, Dec 27, 2018 at 8:47 PM Masaya Suzuki <masayasuzuki@google.com> wrote:
> > When GIT_CURL_VERBOSE is set, libcurl produces request/response headers
> > to stderr. However, if the response is an error response and
> > CURLOPT_FAILONERROR is set, libcurl stops parsing the response, and it
> > won't ump the headers. Showing HTTP response headers is useful for
>
> s/ump/dump/
>
> > debugging, especially for non-OK responses.
> >
> > This is substantially same as setting http_options.keep_error to all
> > requests. Hence, removing this option.
>
> s/removing/remove/
>
> > Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
> > ---
> > diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
> > @@ -0,0 +1,32 @@
> > +test_expect_success 'setup repository' '
> > +       ...
> > +'
> > +
> > +test_expect_success 'create http-accessible bare repository' '
>
> Not a big deal, but this seems like more setup, so it could be folded
> into the "setup" test above it.
>
> > +       mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
> > +       (cd "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
> > +        git --bare init
> > +       ) &&
>
> Since this is a new test script, it makes sense to format the subshell
> in the modern style:
>
>     (
>         cd ... &&
>         git ...
>     ) &&
>
> Alternately, use -C and drop the subshell altogether:
>
>     git -C $BLAH/repo.git --bare init &&
>
> > +       git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
> > +       git push public master:master
> > +'
> > +
> > +test_expect_success 'failure in git-upload-pack is shown' '
> > +       (GIT_CURL_VERBOSE=1 git clone --bare "$HTTPD_URL/error_git_upload_pack/smart/repo.git" 2>curl_log ||
> > +        true) &&
>
> Using test_might_fail() would allow you to drop the subshell and the "|| true":
>
>     test_might_fail env GIT_CURL_VERBOSE=1  git clone ... &&
>
> > +       cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
> > +'

The test should success. This is a test that a log is produced after a git command fails. The point of this test is "cat curl_log | grep ..." part that asserts the log.

Eric Sunshine· Dec 28, 2018, 19:58 UTC · re: Masaya Suzuki · lore

Re: [PATCH 2/2] Unset CURLOPT_FAILONERROR

On Fri, Dec 28, 2018 at 2:51 PM Masaya Suzuki <masayasuzuki@google.com> wrote:
Show 16 quoted lines
> On Fri, Dec 28, 2018 at 11:37 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
> > On Thu, Dec 27, 2018 at 8:47 PM Masaya Suzuki <masayasuzuki@google.com> wrote:
> > > +test_expect_success 'failure in git-upload-pack is shown' '
> > > +       (GIT_CURL_VERBOSE=1 git clone --bare "$HTTPD_URL/error_git_upload_pack/smart/repo.git" 2>curl_log ||
> > > +        true) &&
> >
> > Using test_might_fail() would allow you to drop the subshell and the "|| true":
> >
> >     test_might_fail env GIT_CURL_VERBOSE=1  git clone ... &&
> >
> > > +       cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
> > > +'
>
> The test should success. This is a test that a log is produced after a
> git command fails. The point of this test is "cat curl_log | grep ..."
> part that asserts the log.

Unfortunately, the name "test_might_fail" is confusing. It is not saying that the entire test might or might not fail. Rather, it is saying that the one command might or might not fail (and that you don't care if it does fail). The idiom:

    (some-git-command || true) &&
can be replaced with:
   test_might_fail some-git-command &&

without changing its meaning, and without affecting the success/failure status of the test overall.

So, this new test could be written like this:
--- 8< ---
test_expect_success 'failure in git-upload-pack is shown' '
   test_might_fail env GIT_CURL_VERBOSE=1 git clone --bare
"$HTTPD_URL/error_git_upload_pack/smart/repo.git" 2>curl_log &&
   cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
'
--- 8< ---
and have the same meaning.
Masaya Suzuki· Dec 28, 2018, 20:00 UTC · re: Eric Sunshine · lore

Re: [PATCH 2/2] Unset CURLOPT_FAILONERROR

On Fri, Dec 28, 2018 at 11:58 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
Show 44 quoted lines
>
> On Fri, Dec 28, 2018 at 2:51 PM Masaya Suzuki <masayasuzuki@google.com> wrote:
> > On Fri, Dec 28, 2018 at 11:37 AM Eric Sunshine <sunshine@sunshineco.com> wrote:
> > > On Thu, Dec 27, 2018 at 8:47 PM Masaya Suzuki <masayasuzuki@google.com> wrote:
> > > > +test_expect_success 'failure in git-upload-pack is shown' '
> > > > +       (GIT_CURL_VERBOSE=1 git clone --bare "$HTTPD_URL/error_git_upload_pack/smart/repo.git" 2>curl_log ||
> > > > +        true) &&
> > >
> > > Using test_might_fail() would allow you to drop the subshell and the "|| true":
> > >
> > >     test_might_fail env GIT_CURL_VERBOSE=1  git clone ... &&
> > >
> > > > +       cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
> > > > +'
> >
> > The test should success. This is a test that a log is produced after a
> > git command fails. The point of this test is "cat curl_log | grep ..."
> > part that asserts the log.
>
> Unfortunately, the name "test_might_fail" is confusing. It is not
> saying that the entire test might or might not fail. Rather, it is
> saying that the one command might or might not fail (and that you
> don't care if it does fail). The idiom:
>
>     (some-git-command || true) &&
>
> can be replaced with:
>
>    test_might_fail some-git-command &&
>
> without changing its meaning, and without affecting the
> success/failure status of the test overall.
>
> So, this new test could be written like this:
>
> --- 8< ---
> test_expect_success 'failure in git-upload-pack is shown' '
>    test_might_fail env GIT_CURL_VERBOSE=1 git clone --bare
> "$HTTPD_URL/error_git_upload_pack/smart/repo.git" 2>curl_log &&
>    cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
> '
> --- 8< ---
>
> and have the same meaning.
Ah. I see. It's used inside the test. Thanks.
Masaya Suzuki· Dec 29, 2018, 19:44 UTC · re: Masaya Suzuki · lore

[PATCH v2 0/2] Show HTTP headers of failed requests with GIT_CURL_VERBOSE

When GIT_CURL_VERBOSE is set, libcurl produces request/response headers to stderr. However, if the response is an error response and CURLOPT_FAILONERROR is set, libcurl stops parsing the response, and it won't dump the headers. Showing HTTP response headers is useful for debugging, especially for non-OK responses.

To this end, the caller of libcurl needs to handle HTTP request failures by themselves. The first patch makes git prepared to handle those failures. The second patch actually unsets CURLOPT_FAILONERROR.

Masaya Suzuki (2):
  Change how HTTP response body is returned
  Unset CURLOPT_FAILONERROR
 http.c                       | 103 +++++++++++++++++++----------------
 http.h                       |   1 -
 remote-curl.c                |  30 ++++++++--
 t/lib-httpd/apache.conf      |   1 +
 t/t5581-http-curl-verbose.sh |  28 ++++++++++
 5 files changed, 110 insertions(+), 53 deletions(-)
 create mode 100755 t/t5581-http-curl-verbose.sh
-- 
2.20.1.415.g653613c723-goog
Masaya Suzuki· Dec 29, 2018, 19:44 UTC · re: Masaya Suzuki · lore

[PATCH v2 1/2] Change how HTTP response body is returned

This changes the way HTTP response body is returned in http_request_reauth and post_rpc.

1. http_request_reauth makes up to two requests; one without a
   credential and one with a credential. The first request can fail if
   it needs a credential. When the keep_error option is specified, the
   response to the first request can be written to the HTTP response
   body destination. If the response body destination is a string
   buffer, it erases the buffer before making the second request. By
   introducing http_response_dest, it can handle the case that the
   destination is a file handle.
2. post_rpc makes an HTTP request and the response body is directly
   written to a file descriptor. This makes it check the HTTP status
   code before writing it, and do not write the response body if it's an
   error response. It's ok without this check now because post_rpc makes
   a request with CURLOPT_FAILONERROR, and libcurl won't call the
   callback if the response has an error status code.
Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c        | 99 +++++++++++++++++++++++++++++----------------------
 remote-curl.c | 29 ++++++++++++---
 2 files changed, 81 insertions(+), 47 deletions(-)
Show changes to 2 files +81 −47

http.c, remote-curl.c

diff --git a/http.c b/http.c
index eacc2a75e..d23417670 100644
--- a/http.c
+++ b/http.c
@@ -165,6 +165,19 @@ static int http_schannel_check_revoke = 1;
  */
 static int http_schannel_use_ssl_cainfo;
 
+/*
+ * Where to store the result of http_request.
+ *
+ * At most one of buffer or file can be non-NULL. The buffer and file are not
+ * allocated by http_request, and the caller is responsible for releasing them.
+ */
+struct http_response_dest {
+	struct strbuf *buffer;
+
+	FILE *file;
+	const char *filename;
+};
+
 size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
 {
 	size_t size = eltsize * nmemb;
@@ -1794,12 +1807,8 @@ static void http_opt_request_remainder(CURL *curl, off_t pos)
 	curl_easy_setopt(curl, CURLOPT_RANGE, buf);
 }
 
-/* http_request() targets */
-#define HTTP_REQUEST_STRBUF	0
-#define HTTP_REQUEST_FILE	1
-
 static int http_request(const char *url,
-			void *result, int target,
+			struct http_response_dest *dest,
 			const struct http_get_options *options)
 {
 	struct active_request_slot *slot;
@@ -1812,21 +1821,23 @@ static int http_request(const char *url,
 	slot = get_active_slot();
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
 
-	if (result == NULL) {
-		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
-	} else {
+	if (dest->file) {
+		off_t posn = ftello(dest->file);
 		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
-		curl_easy_setopt(slot->curl, CURLOPT_FILE, result);
-
-		if (target == HTTP_REQUEST_FILE) {
-			off_t posn = ftello(result);
-			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
-					 fwrite);
-			if (posn > 0)
-				http_opt_request_remainder(slot->curl, posn);
-		} else
-			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
-					 fwrite_buffer);
+		curl_easy_setopt(slot->curl, CURLOPT_FILE,
+				 dest->file);
+		curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+				 fwrite);
+		if (posn > 0)
+			http_opt_request_remainder(slot->curl, posn);
+	} else if (dest->buffer) {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
+		curl_easy_setopt(slot->curl, CURLOPT_FILE,
+				 dest->buffer);
+		curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
+				 fwrite_buffer);
+	} else {
+		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
 	}
 
 	accept_language = get_accept_language();
@@ -1930,10 +1941,10 @@ static int update_url_from_redirect(struct strbuf *base,
 }
 
 static int http_request_reauth(const char *url,
-			       void *result, int target,
+			       struct http_response_dest *dest,
 			       struct http_get_options *options)
 {
-	int ret = http_request(url, result, target, options);
+	int ret = http_request(url, dest, options);
 
 	if (ret != HTTP_OK && ret != HTTP_REAUTH)
 		return ret;
@@ -1949,32 +1960,34 @@ static int http_request_reauth(const char *url,
 	if (ret != HTTP_REAUTH)
 		return ret;
 
-	/*
-	 * If we are using KEEP_ERROR, the previous request may have
-	 * put cruft into our output stream; we should clear it out before
-	 * making our next request. We only know how to do this for
-	 * the strbuf case, but that is enough to satisfy current callers.
-	 */
-	if (options && options->keep_error) {
-		switch (target) {
-		case HTTP_REQUEST_STRBUF:
-			strbuf_reset(result);
-			break;
-		default:
-			BUG("HTTP_KEEP_ERROR is only supported with strbufs");
+	if (dest->file) {
+		/*
+		 * At this point, the file contains the response body of the
+		 * previous request. We need to truncate the file.
+		 */
+		FILE *new_file = freopen(dest->filename, "w", dest->file);
+		if (new_file == NULL) {
+			error("Unable to open local file %s", dest->filename);
+			return HTTP_ERROR;
 		}
+		dest->file = new_file;
+	} else if (dest->buffer) {
+		strbuf_reset(dest->buffer);
 	}
 
 	credential_fill(&http_auth);
 
-	return http_request(url, result, target, options);
+	return http_request(url, dest, options);
 }
 
 int http_get_strbuf(const char *url,
-		    struct strbuf *result,
+		    struct strbuf *dest_buffer,
 		    struct http_get_options *options)
 {
-	return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
+	struct http_response_dest dest;
+	dest.file = NULL;
+	dest.buffer = dest_buffer;
+	return http_request_reauth(url, &dest, options);
 }
 
 /*
@@ -1988,18 +2001,20 @@ static int http_get_file(const char *url, const char *filename,
 {
 	int ret;
 	struct strbuf tmpfile = STRBUF_INIT;
-	FILE *result;
+	struct http_response_dest dest;
 
 	strbuf_addf(&tmpfile, "%s.temp", filename);
-	result = fopen(tmpfile.buf, "a");
-	if (!result) {
+	dest.buffer = NULL;
+	dest.file = fopen(tmpfile.buf, "a");
+	if (!dest.file) {
 		error("Unable to open local file %s", tmpfile.buf);
 		ret = HTTP_ERROR;
 		goto cleanup;
 	}
+	dest.filename = tmpfile.buf;
 
-	ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
-	fclose(result);
+	ret = http_request_reauth(url, &dest, options);
+	fclose(dest.file);
 
 	if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
 		ret = HTTP_ERROR;
diff --git a/remote-curl.c b/remote-curl.c
index 1220dffcd..48656bf18 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -546,14 +546,31 @@ static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
 }
 #endif
 
+struct rpc_in_data {
+	struct rpc_state *rpc;
+	struct active_request_slot *slot;
+};
+
+/*
+ * A callback for CURLOPT_WRITEFUNCTION. The return value is the bytes consumed
+ * from ptr.
+ */
 static size_t rpc_in(char *ptr, size_t eltsize,
 		size_t nmemb, void *buffer_)
 {
 	size_t size = eltsize * nmemb;
-	struct rpc_state *rpc = buffer_;
+	struct rpc_in_data *data = buffer_;
+	long response_code;
+
+	if (curl_easy_getinfo(data->slot->curl, CURLINFO_RESPONSE_CODE,
+			      &response_code) != CURLE_OK)
+		return size;
+	if (response_code != 200)
+		return size;
+
 	if (size)
-		rpc->any_written = 1;
-	write_or_die(rpc->in, ptr, size);
+		data->rpc->any_written = 1;
+	write_or_die(data->rpc->in, ptr, size);
 	return size;
 }
 
@@ -633,6 +650,7 @@ static int post_rpc(struct rpc_state *rpc)
 	size_t gzip_size = 0;
 	int err, large_request = 0;
 	int needs_100_continue = 0;
+	struct rpc_in_data rpc_in_data;
 
 	/* Try to load the entire request, if we can fit it into the
 	 * allocated buffer space we can use HTTP/1.0 and avoid the
@@ -765,8 +783,9 @@ static int post_rpc(struct rpc_state *rpc)
 
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
-
+	rpc_in_data.rpc = rpc;
+	rpc_in_data.slot = slot;
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
 
 	rpc->any_written = 0;
 	err = run_slot(slot, NULL);
-- 
2.20.1.415.g653613c723-goog
Junio C Hamano· Jan 3, 2019, 19:09 UTC · re: Masaya Suzuki · lore

Re: [PATCH v2 1/2] Change how HTTP response body is returned

Masaya Suzuki <masayasuzuki@google.com> writes:
> Subject: Re: [PATCH v2 1/2] Change how HTTP response body is returned
Perhaps:
    Subject: http: change the way response body is returned

but if we can state why we want to do so concisely, that would be even better.

Show 17 quoted lines
> This changes the way HTTP response body is returned in
> http_request_reauth and post_rpc.
>
> 1. http_request_reauth makes up to two requests; one without a
>    credential and one with a credential. The first request can fail if
>    it needs a credential. When the keep_error option is specified, the
>    response to the first request can be written to the HTTP response
>    body destination. If the response body destination is a string
>    buffer, it erases the buffer before making the second request. By
>    introducing http_response_dest, it can handle the case that the
>    destination is a file handle.
> 2. post_rpc makes an HTTP request and the response body is directly
>    written to a file descriptor. This makes it check the HTTP status
>    code before writing it, and do not write the response body if it's an
>    error response. It's ok without this check now because post_rpc makes
>    a request with CURLOPT_FAILONERROR, and libcurl won't call the
>    callback if the response has an error status code.

The above may be an accurate description of what the code will do with this patch, but I cannot quite read the reason why we would want the code to behave so in the first place.

Show 56 quoted lines
>
> Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
> ---
>  http.c        | 99 +++++++++++++++++++++++++++++----------------------
>  remote-curl.c | 29 ++++++++++++---
>  2 files changed, 81 insertions(+), 47 deletions(-)
>
> diff --git a/http.c b/http.c
> index eacc2a75e..d23417670 100644
> --- a/http.c
> +++ b/http.c
> @@ -165,6 +165,19 @@ static int http_schannel_check_revoke = 1;
>   */
>  static int http_schannel_use_ssl_cainfo;
>  
> +/*
> + * Where to store the result of http_request.
> + *
> + * At most one of buffer or file can be non-NULL. The buffer and file are not
> + * allocated by http_request, and the caller is responsible for releasing them.
> + */
> +struct http_response_dest {
> +	struct strbuf *buffer;
> +
> +	FILE *file;
> +	const char *filename;
> +};
> +
>  size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
>  {
>  	size_t size = eltsize * nmemb;
> @@ -1794,12 +1807,8 @@ static void http_opt_request_remainder(CURL *curl, off_t pos)
>  	curl_easy_setopt(curl, CURLOPT_RANGE, buf);
>  }
>  
> -/* http_request() targets */
> -#define HTTP_REQUEST_STRBUF	0
> -#define HTTP_REQUEST_FILE	1
> -
>  static int http_request(const char *url,
> -			void *result, int target,
> +			struct http_response_dest *dest,
>  			const struct http_get_options *options)
>  {
>  	struct active_request_slot *slot;
> @@ -1812,21 +1821,23 @@ static int http_request(const char *url,
>  	slot = get_active_slot();
>  	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
>  
> -	if (result == NULL) {
> -		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
> -	} else {
> +	if (dest->file) {
> +		off_t posn = ftello(dest->file);
>  		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
> -		curl_easy_setopt(slot->curl, CURLOPT_FILE, result);

OK, so it used to be that we can either discard the result (i.e. NOBODY) or send the result to CURLOPT_FILE, and the latter has two options (sent to a file, or sent to in-core buffer). The way these three choices are given were with the result pointer and the target enum.

That is replaced by a struct that allows the same three choices.
Makes sense so far.
Show 10 quoted lines
> @@ -1930,10 +1941,10 @@ static int update_url_from_redirect(struct strbuf *base,
>  }
>  
>  static int http_request_reauth(const char *url,
> -			       void *result, int target,
> +			       struct http_response_dest *dest,
>  			       struct http_get_options *options)
>  {
> -	int ret = http_request(url, result, target, options);
> +	int ret = http_request(url, dest, options);
Just adjusting the calling convention to the change we saw above.
Show 17 quoted lines
> @@ -1949,32 +1960,34 @@ static int http_request_reauth(const char *url,
>  	if (ret != HTTP_REAUTH)
>  		return ret;
>  
> -	/*
> -	 * If we are using KEEP_ERROR, the previous request may have
> -	 * put cruft into our output stream; we should clear it out before
> -	 * making our next request. We only know how to do this for
> -	 * the strbuf case, but that is enough to satisfy current callers.
> -	 */
> -	if (options && options->keep_error) {
> -		switch (target) {
> -		case HTTP_REQUEST_STRBUF:
> -			strbuf_reset(result);
> -			break;
> -		default:
> -			BUG("HTTP_KEEP_ERROR is only supported with strbufs");

Now it gets interesting. We used to allow keep-error only when receiving to in-core buffer.

Show 6 quoted lines
> +	if (dest->file) {
> +		/*
> +		 * At this point, the file contains the response body of the
> +		 * previous request. We need to truncate the file.
> +		 */
> +		FILE *new_file = freopen(dest->filename, "w", dest->file);
Now freopen() lets us restart the file anew with a new "FILE *".
> +		if (new_file == NULL) {
> +			error("Unable to open local file %s", dest->filename);
error_errno(), perhaps?

At this point, I presume that dest->file is closed by the failed freopen(), but dest->file is still non-NULL and causes further calls to http_request() with this dest would be a disaster? As long as the caller of this function reacts to HTTP_ERROR and kill the dest, it would be fine.

Show 6 quoted lines
> +			return HTTP_ERROR;
>  		}
> +		dest->file = new_file;
> +	} else if (dest->buffer) {
> +		strbuf_reset(dest->buffer);
>  	}
OK.
Show 5 quoted lines
>  	credential_fill(&http_auth);
>  
> -	return http_request(url, result, target, options);
> +	return http_request(url, dest, options);
>  }

So far, I spotted one reason why this patch wants to exist: it used to be that keep_error was impossible when sending to a file. It somehow wants to allow us to do so (even though it still is unclear who that new caller that wants to use keep_error is, and for what purpose it wants to use that facility).

Perhaps this step can be split into at least two steps? The first one is to turn <result, target> to <dest> without changing any other behaviour, and then the second one implements keep_error handling for the "dest->file != NULL" case.

There may be other things this patch does, in which case it may deserve to become three or more steps, but we haven't seen enough to decide if that is the case. Let's read on.

Show 10 quoted lines
>  int http_get_strbuf(const char *url,
> -		    struct strbuf *result,
> +		    struct strbuf *dest_buffer,
>  		    struct http_get_options *options)
>  {
> -	return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
> +	struct http_response_dest dest;
> +	dest.file = NULL;
> +	dest.buffer = dest_buffer;
> +	return http_request_reauth(url, &dest, options);

This is merely adjusting for the updated calling convention, which makes sense.

Show 21 quoted lines
>  }
>  
>  /*
> @@ -1988,18 +2001,20 @@ static int http_get_file(const char *url, const char *filename,
>  {
>  	int ret;
>  	struct strbuf tmpfile = STRBUF_INIT;
> -	FILE *result;
> +	struct http_response_dest dest;
>  
>  	strbuf_addf(&tmpfile, "%s.temp", filename);
> -	result = fopen(tmpfile.buf, "a");
> -	if (!result) {
> +	dest.buffer = NULL;
> +	dest.file = fopen(tmpfile.buf, "a");
> +	if (!dest.file) {
>  		error("Unable to open local file %s", tmpfile.buf);
>  		ret = HTTP_ERROR;
>  		goto cleanup;
>  	}
> +	dest.filename = tmpfile.buf;

Hmph. I somehow expected that the presence of dest.filename field would allow callers to just set it and let the fopen() call handled in http_request(), e.g. at the beginning of the function, it would do something like

	if (!dest->file && dest->filename)
		dest->file = fopen(...);

But obviously that is not within the scope of this change. Leaving the caller responsible for opening and reporting errors as before like the above is preferrable.

Show 38 quoted lines
> diff --git a/remote-curl.c b/remote-curl.c
> index 1220dffcd..48656bf18 100644
> --- a/remote-curl.c
> +++ b/remote-curl.c
> @@ -546,14 +546,31 @@ static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
>  }
>  #endif
>  
> +struct rpc_in_data {
> +	struct rpc_state *rpc;
> +	struct active_request_slot *slot;
> +};
> +
> +/*
> + * A callback for CURLOPT_WRITEFUNCTION. The return value is the bytes consumed
> + * from ptr.
> + */
>  static size_t rpc_in(char *ptr, size_t eltsize,
>  		size_t nmemb, void *buffer_)
>  {
>  	size_t size = eltsize * nmemb;
> -	struct rpc_state *rpc = buffer_;
> +	struct rpc_in_data *data = buffer_;
> +	long response_code;
> +
> +	if (curl_easy_getinfo(data->slot->curl, CURLINFO_RESPONSE_CODE,
> +			      &response_code) != CURLE_OK)
> +		return size;
> +	if (response_code != 200)
> +		return size;
> +
>  	if (size)
> -		rpc->any_written = 1;
> -	write_or_die(rpc->in, ptr, size);
> +		data->rpc->any_written = 1;
> +	write_or_die(data->rpc->in, ptr, size);
>  	return size;
>  }

This is not necessarily related to the change we saw in http.c but making it more careful in general? That is, we avoid writing the payload to the destination (by the way, rpc->IN being the target of write(2) is somewhat a brain-twister). It may deserve to become its own step in a patch series, with separate justification (i.e. "when rpc channel receives an error from the cURL library, we used to write the data to the file anyway, and that caused such and such problems, as demonstrated by the new test added by this patch. we fix it by checking for the error before writing to the file").

Show 20 quoted lines
> @@ -633,6 +650,7 @@ static int post_rpc(struct rpc_state *rpc)
>  	size_t gzip_size = 0;
>  	int err, large_request = 0;
>  	int needs_100_continue = 0;
> +	struct rpc_in_data rpc_in_data;
>  
>  	/* Try to load the entire request, if we can fit it into the
>  	 * allocated buffer space we can use HTTP/1.0 and avoid the
> @@ -765,8 +783,9 @@ static int post_rpc(struct rpc_state *rpc)
>  
>  	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
>  	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
> -	curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
> -
> +	rpc_in_data.rpc = rpc;
> +	rpc_in_data.slot = slot;
> +	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
>  
>  	rpc->any_written = 0;
>  	err = run_slot(slot, NULL);

These two hunks look like mere adjustments for the new callback type, which makes sense.

Thanks.
Jeff King· Jan 4, 2019, 10:11 UTC · re: Junio C Hamano · lore

Re: [PATCH v2 1/2] Change how HTTP response body is returned

On Thu, Jan 03, 2019 at 11:09:02AM -0800, Junio C Hamano wrote:
Show 19 quoted lines
> > +	if (dest->file) {
> > +		/*
> > +		 * At this point, the file contains the response body of the
> > +		 * previous request. We need to truncate the file.
> > +		 */
> > +		FILE *new_file = freopen(dest->filename, "w", dest->file);
> 
> Now freopen() lets us restart the file anew with a new "FILE *".
> 
> > +		if (new_file == NULL) {
> > +			error("Unable to open local file %s", dest->filename);
> 
> error_errno(), perhaps?
> 
> At this point, I presume that dest->file is closed by the failed
> freopen(), but dest->file is still non-NULL and causes further calls
> to http_request() with this dest would be a disaster?  As long as
> the caller of this function reacts to HTTP_ERROR and kill the dest,
> it would be fine.

I also wondered what timing guarantees freopen() gives us (i.e., is it possible for it to open and truncate the file, and then close the old handle, flushing some in-memory buffer). C99 says:

  The freopen function first attempts to close any file that is
  associated with the specified stream. Failure to close the file is
  ignored. The error and end-of-file indicators for the stream are
  cleared.

So I think the order is OK for my concern, but not for yours. I.e., on an error, dest->file is now undefined.

It might be nice to set "dest->file == NULL" in that case. There's no guarantee that the caller did not hold onto its own copy of the handle, but since this struct is only exposed internally within http.c, that's probably OK.

The most robust thing would perhaps be:
  fflush(dest->file);
  ftruncate(fileno(dest->file), 0);
which leaves the handle intact.

(I agree with the rest of your review, especially that it would be easier to read if this were split into separate refactor and change-behavior steps).

-Peff
Junio C Hamano· Jan 4, 2019, 20:13 UTC · re: Jeff King · lore

Re: [PATCH v2 1/2] Change how HTTP response body is returned

Jeff King <peff@peff.net> writes:
Show 6 quoted lines
> The most robust thing would perhaps be:
>
>   fflush(dest->file);
>   ftruncate(fileno(dest->file), 0);
>
> which leaves the handle intact.

An added benefit of that approach is that there is no need for the filename field in the dest structure.

Having a separate filename field could be a positive flexibility (it could be used to open a file, store its FILE* in dest->file, while storing the name of another file in dest->filename), but also a negative flexibility (dest->file possibly pointing to a file different from dest->filename is a source of confusion). As I do not think any current caller that wants such a flexibility, or callers in any immediate future, it probably is an overall plus if we do not have to add the dest->filename field.

Show 5 quoted lines
> (I agree with the rest of your review, especially that it would be
> easier to read if this were split into separate refactor and
> change-behavior steps).
>
> -Peff
Jeff King· Jan 4, 2019, 10:30 UTC · re: Masaya Suzuki · lore

Re: [PATCH v2 1/2] Change how HTTP response body is returned

On Sat, Dec 29, 2018 at 11:44:46AM -0800, Masaya Suzuki wrote:
Show 15 quoted lines
> +/*
> + * A callback for CURLOPT_WRITEFUNCTION. The return value is the bytes consumed
> + * from ptr.
> + */
>  static size_t rpc_in(char *ptr, size_t eltsize,
>  		size_t nmemb, void *buffer_)
>  {
>  	size_t size = eltsize * nmemb;
> -	struct rpc_state *rpc = buffer_;
> +	struct rpc_in_data *data = buffer_;
> +	long response_code;
> +
> +	if (curl_easy_getinfo(data->slot->curl, CURLINFO_RESPONSE_CODE,
> +			      &response_code) != CURLE_OK)
> +		return size;

This hunk was unexpected to me. The function here is just writing out the data, and I expected we'd handle the error after the whole transfer is done. But we do that anyway eventually via run_slot() (which uses handle_curl_result). I guess the goal here is to start throwing away data when we see an error, rather than storing it?

That makes some sense, though I do wonder if there's any case where curl would call our WRITEFUNCTION before it knows the HTTP status. That implies a body before our header, which seems impossible, though.

> +	if (response_code != 200)
> +		return size;

The current behavior with CURLOPT_FAILONERROR treats codes >= 400 as an error. And in handle_curl_result(), we treat >= 300 as an error (since we only see 3xx for a disabled redirect). I suppose it's unlikely for us to see any success code besides 200, but we probably ought to be following the same rules here.

-Peff
Masaya Suzuki· Dec 29, 2018, 19:44 UTC · re: Masaya Suzuki · lore

[PATCH v2 2/2] Unset CURLOPT_FAILONERROR

When GIT_CURL_VERBOSE is set, libcurl produces request/response headers to stderr. However, if the response is an error response and CURLOPT_FAILONERROR is set, libcurl stops parsing the response, and it won't dump the headers. Showing HTTP response headers is useful for debugging, especially for non-OK responses.

This is substantially same as setting http_options.keep_error to all requests. Hence, remove this option.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c                       |  4 ----
 http.h                       |  1 -
 remote-curl.c                |  1 -
 t/lib-httpd/apache.conf      |  1 +
 t/t5581-http-curl-verbose.sh | 28 ++++++++++++++++++++++++++++
 5 files changed, 29 insertions(+), 6 deletions(-)
 create mode 100755 t/t5581-http-curl-verbose.sh
Show changes to 5 files +29 −6

http.c, http.h, remote-curl.c, t/lib-httpd/apache.conf, t/t5581-http-curl-verbose.sh

diff --git a/http.c b/http.c
index d23417670..8f8101da3 100644
--- a/http.c
+++ b/http.c
@@ -1269,7 +1269,6 @@ struct active_request_slot *get_active_slot(void)
 	curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
 	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
-	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
 	curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);
 
 	/*
@@ -1848,8 +1847,6 @@ static int http_request(const char *url,
 	strbuf_addstr(&buf, "Pragma:");
 	if (options && options->no_cache)
 		strbuf_addstr(&buf, " no-cache");
-	if (options && options->keep_error)
-		curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 	if (options && options->initial_request &&
 	    http_follow_config == HTTP_FOLLOW_INITIAL)
 		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
@@ -2415,7 +2412,6 @@ struct http_object_request *new_http_object_request(const char *base_url,
 	freq->slot = get_active_slot();
 
 	curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
-	curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
 	curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
 	curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
 	curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
diff --git a/http.h b/http.h
index d305ca1dc..eebf40688 100644
--- a/http.h
+++ b/http.h
@@ -146,7 +146,6 @@ extern char *get_remote_object_url(const char *url, const char *hex,
 /* Options for http_get_*() */
 struct http_get_options {
 	unsigned no_cache:1,
-		 keep_error:1,
 		 initial_request:1;
 
 	/* If non-NULL, returns the content-type of the response. */
diff --git a/remote-curl.c b/remote-curl.c
index 48656bf18..43e7a1d80 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -380,7 +380,6 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
-	http_options.keep_error = 1;
 
 	http_ret = http_get_strbuf(refs_url.buf, &buffer, &http_options);
 	switch (http_ret) {
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 581c010d8..cc4b87507 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -115,6 +115,7 @@ Alias /auth/dumb/ www/auth/dumb/
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
 </LocationMatch>
+ScriptAliasMatch /error_git_upload_pack/(.*)/git-upload-pack error.sh/
 ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
 ScriptAlias /broken_smart/ broken-smart-http.sh/
 ScriptAlias /error/ error.sh/
diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
new file mode 100755
index 000000000..73148eeba
--- /dev/null
+++ b/t/t5581-http-curl-verbose.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+test_description='test GIT_CURL_VERBOSE'
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'setup repository' '
+	mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" --bare init &&
+	git config push.default matching &&
+	echo content >file &&
+	git add file &&
+	git commit -m one &&
+	git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git push public master:master
+'
+
+test_expect_success 'failure in git-upload-pack is shown' '
+	test_might_fail env GIT_CURL_VERBOSE=1 \
+		git clone "$HTTPD_URL/error_git_upload_pack/smart/repo.git" \
+		2>curl_log &&
+	cat curl_log | grep "< HTTP/1.1 500 Intentional Breakage"
+'
+
+stop_httpd
+
+test_done
-- 
2.20.1.415.g653613c723-goog
Jeff King· Jan 4, 2019, 10:49 UTC · re: Masaya Suzuki · lore

Re: [PATCH v2 2/2] Unset CURLOPT_FAILONERROR

On Sat, Dec 29, 2018 at 11:44:47AM -0800, Masaya Suzuki wrote:
Show 5 quoted lines
> When GIT_CURL_VERBOSE is set, libcurl produces request/response headers
> to stderr. However, if the response is an error response and
> CURLOPT_FAILONERROR is set, libcurl stops parsing the response, and it
> won't dump the headers. Showing HTTP response headers is useful for
> debugging, especially for non-OK responses.

Out of curiosity, does GIT_TRACE_CURL do any better? Or is it simply that curl closes the handle when it sees the bad response code, and nobody ever gets to see the rest of the data?

> This is substantially same as setting http_options.keep_error to all
> requests. Hence, remove this option.

The assumption here is that every code path using FAILONERROR is prepared to handle the failing http response codes itself (since we no longer set it at all in get_active_slot()). Is that so?

Anything that uses handle_curl_result() is OK. That means run_one_slot() is fine, which in turn covers run_slot() for RPCs, and http_request() for normal one-at-a-time requests. But what about the parallel multiple requests issued by the dumb-http walker code?

There I think we end up in step_active_slots(), which calls into finish_active_slot() for completed requests. I think that unconditionally fetches the http code without bothering to look at whether curl reported success or not.

So I _think_ that's probably all of the users of the curl handles provided by get_active_slot(). Though given the tangled mess of our HTTP code, I won't be surprised if there's a corner case I missed in that analysis.

-Peff
Masaya Suzuki· Jan 7, 2019, 23:24 UTC · re: Jeff King · lore

Re: [PATCH v2 2/2] Unset CURLOPT_FAILONERROR

On Fri, Jan 4, 2019 at 2:49 AM Jeff King <peff@peff.net> wrote:
Show 12 quoted lines
>
> On Sat, Dec 29, 2018 at 11:44:47AM -0800, Masaya Suzuki wrote:
>
> > When GIT_CURL_VERBOSE is set, libcurl produces request/response headers
> > to stderr. However, if the response is an error response and
> > CURLOPT_FAILONERROR is set, libcurl stops parsing the response, and it
> > won't dump the headers. Showing HTTP response headers is useful for
> > debugging, especially for non-OK responses.
>
> Out of curiosity, does GIT_TRACE_CURL do any better? Or is it simply
> that curl closes the handle when it sees the bad response code, and
> nobody ever gets to see the rest of the data?

curl disregards the rest of the contents when it sees a bad response code when CURLOPT_FAILONERROR is set (https://github.com/curl/curl/blob/dea3f94298ac0859464768959488938c4e104545/lib/http.c#L3691). So nobody gets the rest of the data.

Show 7 quoted lines
>
> > This is substantially same as setting http_options.keep_error to all
> > requests. Hence, remove this option.
>
> The assumption here is that every code path using FAILONERROR is
> prepared to handle the failing http response codes itself (since we no
> longer set it at all in get_active_slot()). Is that so?

I was thinking that I covered the all code paths using FAILONERROR, but it seems it's not the case. http-walker.c and http-push.c also calls get_active_slot(). I'll narrow down the scope on removing FAILONERROR.

Show 5 quoted lines
>
> Anything that uses handle_curl_result() is OK. That means run_one_slot()
> is fine, which in turn covers run_slot() for RPCs, and http_request()
> for normal one-at-a-time requests. But what about the parallel multiple
> requests issued by the dumb-http walker code?

Right. I'll keep FAILONERROR in get_active_slot and remove it only for the code paths that can handle HTTP errors.

Show 12 quoted lines
>
> There I think we end up in step_active_slots(), which calls into
> finish_active_slot() for completed requests. I think that
> unconditionally fetches the http code without bothering to look at
> whether curl reported success or not.
>
> So I _think_ that's probably all of the users of the curl handles
> provided by get_active_slot(). Though given the tangled mess of our HTTP
> code, I won't be surprised if there's a corner case I missed in that
> analysis.
>
> -Peff
Masaya Suzuki· Jan 8, 2019, 02:47 UTC · re: Masaya Suzuki · lore

[PATCH v3 0/5] Show HTTP headers of failed requests with GIT_CURL_VERBOSE

Diff from v2[1]:
*   Remove http_resonse_dest
    This was introduced to have a filename for freopen. Jeff King proposed [2]
    using fflush and ftruncate and this makes this struct not needed.
*   Unset CURLOPT_FAILONERROR only when it's necessary.
    Previously, CURLOPT_FAILONERROR was unset for everything. This patch series
    does so only when it's necessary. This is from the observation in [3] that
    pointed out there are other possible code paths that hit http.c.
*   Split the patches for easier review

[1]: https://public-inbox.org/git/20181229194447.157763-1-masayasuzuki@google.com/ [2]: https://public-inbox.org/git/20190104101149.GA26185@sigill.intra.peff.net/ [3]: https://public-inbox.org/git/20190104104907.GC26185@sigill.intra.peff.net/

Masaya Suzuki (5):
  http: support file handles for HTTP_KEEP_ERROR
  http: enable keep_error for HTTP requests
  remote-curl: define struct for CURLOPT_WRITEFUNCTION
  remote-curl: unset CURLOPT_FAILONERROR
  test: test GIT_CURL_VERBOSE=1 shows an error
 http.c                       | 27 +++++++++++++--------------
 http.h                       |  1 -
 remote-curl.c                | 29 ++++++++++++++++++++++++-----
 t/lib-httpd/apache.conf      |  1 +
 t/t5581-http-curl-verbose.sh | 28 ++++++++++++++++++++++++++++
 5 files changed, 66 insertions(+), 20 deletions(-)
 create mode 100755 t/t5581-http-curl-verbose.sh
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 8, 2019, 02:47 UTC · re: Masaya Suzuki · lore

[PATCH v3 1/5] http: support file handles for HTTP_KEEP_ERROR

HTTP_KEEP_ERROR makes it easy to debug HTTP transport errors. In order to make HTTP_KEEP_ERROR enabled for all requests, file handles need to be supported.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
Show changes to http.c +6 −3
diff --git a/http.c b/http.c
index 0b6807cef9..06450da96e 100644
--- a/http.c
+++ b/http.c
@@ -1991,16 +1991,19 @@ static int http_request_reauth(const char *url,
 	/*
 	 * If we are using KEEP_ERROR, the previous request may have
 	 * put cruft into our output stream; we should clear it out before
-	 * making our next request. We only know how to do this for
-	 * the strbuf case, but that is enough to satisfy current callers.
+	 * making our next request.
 	 */
 	if (options && options->keep_error) {
 		switch (target) {
 		case HTTP_REQUEST_STRBUF:
 			strbuf_reset(result);
 			break;
+		case HTTP_REQUEST_FILE:
+			fflush(result);
+			ftruncate(fileno(result), 0);
+			break;
 		default:
-			BUG("HTTP_KEEP_ERROR is only supported with strbufs");
+			BUG("Unknown http_request target");
 		}
 	}
 
-- 
2.20.1.97.g81188d93c3-goog
SZEDER Gábor· Jan 9, 2019, 12:15 UTC · re: Masaya Suzuki · lore

Re: [PATCH v3 1/5] http: support file handles for HTTP_KEEP_ERROR

On Mon, Jan 07, 2019 at 06:47:37PM -0800, Masaya Suzuki wrote:
Show 29 quoted lines
> HTTP_KEEP_ERROR makes it easy to debug HTTP transport errors. In order
> to make HTTP_KEEP_ERROR enabled for all requests, file handles need to
> be supported.
> 
> Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
> ---
>  http.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/http.c b/http.c
> index 0b6807cef9..06450da96e 100644
> --- a/http.c
> +++ b/http.c
> @@ -1991,16 +1991,19 @@ static int http_request_reauth(const char *url,
>  	/*
>  	 * If we are using KEEP_ERROR, the previous request may have
>  	 * put cruft into our output stream; we should clear it out before
> -	 * making our next request. We only know how to do this for
> -	 * the strbuf case, but that is enough to satisfy current callers.
> +	 * making our next request.
>  	 */
>  	if (options && options->keep_error) {
>  		switch (target) {
>  		case HTTP_REQUEST_STRBUF:
>  			strbuf_reset(result);
>  			break;
> +		case HTTP_REQUEST_FILE:
> +			fflush(result);
> +			ftruncate(fileno(result), 0);
Some GCC versions complain about the above line:
  http.c: In function ‘http_request_reauth’:
  http.c:1961:3: error: ignoring return value of ‘ftruncate’, declared with attribute warn_unused_result [-Werror=unused-result]
     ftruncate(fileno(result), 0);
     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
      CC shell.o
      CC remote-testsvn.o
      CC vcs-svn/line_buffer.o
  cc1: all warnings being treated as errors
  make: *** [http.o] Error 1
  make: *** Waiting for unfinished jobs....
Show 10 quoted lines
> +			break;
>  		default:
> -			BUG("HTTP_KEEP_ERROR is only supported with strbufs");
> +			BUG("Unknown http_request target");
>  		}
>  	}
>  
> -- 
> 2.20.1.97.g81188d93c3-goog
> 
Masaya Suzuki· Jan 8, 2019, 02:47 UTC · re: Masaya Suzuki · lore

[PATCH v3 2/5] http: enable keep_error for HTTP requests

curl stops parsing a response when it sees a bad HTTP status code and it has CURLOPT_FAILONERROR set. This prevents GIT_CURL_VERBOSE to show HTTP headers on error.

keep_error is an option to receive the HTTP response body for those error responses. By enabling this option, curl will process the HTTP response headers, and they're shown if GIT_CURL_VERBOSE is set.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c        | 30 +++++++++++++-----------------
 http.h        |  1 -
 remote-curl.c |  1 -
 3 files changed, 13 insertions(+), 19 deletions(-)
Show changes to 3 files +13 −19

http.c, http.h, remote-curl.c

diff --git a/http.c b/http.c
index 06450da96e..a72db87723 100644
--- a/http.c
+++ b/http.c
@@ -1876,8 +1876,6 @@ static int http_request(const char *url,
 	strbuf_addstr(&buf, "Pragma:");
 	if (options && options->no_cache)
 		strbuf_addstr(&buf, " no-cache");
-	if (options && options->keep_error)
-		curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 	if (options && options->initial_request &&
 	    http_follow_config == HTTP_FOLLOW_INITIAL)
 		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
@@ -1895,6 +1893,7 @@ static int http_request(const char *url,
 	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
+	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 
 	ret = run_one_slot(slot, &results);
 
@@ -1989,22 +1988,19 @@ static int http_request_reauth(const char *url,
 		return ret;
 
 	/*
-	 * If we are using KEEP_ERROR, the previous request may have
-	 * put cruft into our output stream; we should clear it out before
-	 * making our next request.
+	 * The previous request may have put cruft into our output stream; we
+	 * should clear it out before making our next request.
 	 */
-	if (options && options->keep_error) {
-		switch (target) {
-		case HTTP_REQUEST_STRBUF:
-			strbuf_reset(result);
-			break;
-		case HTTP_REQUEST_FILE:
-			fflush(result);
-			ftruncate(fileno(result), 0);
-			break;
-		default:
-			BUG("Unknown http_request target");
-		}
+	switch (target) {
+	case HTTP_REQUEST_STRBUF:
+		strbuf_reset(result);
+		break;
+	case HTTP_REQUEST_FILE:
+		fflush(result);
+		ftruncate(fileno(result), 0);
+		break;
+	default:
+		BUG("Unknown http_request target");
 	}
 
 	credential_fill(&http_auth);
diff --git a/http.h b/http.h
index d305ca1dc7..eebf40688c 100644
--- a/http.h
+++ b/http.h
@@ -146,7 +146,6 @@ extern char *get_remote_object_url(const char *url, const char *hex,
 /* Options for http_get_*() */
 struct http_get_options {
 	unsigned no_cache:1,
-		 keep_error:1,
 		 initial_request:1;
 
 	/* If non-NULL, returns the content-type of the response. */
diff --git a/remote-curl.c b/remote-curl.c
index 1220dffcdc..d8eda2380a 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -380,7 +380,6 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
-	http_options.keep_error = 1;
 
 	http_ret = http_get_strbuf(refs_url.buf, &buffer, &http_options);
 	switch (http_ret) {
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 8, 2019, 02:47 UTC · re: Masaya Suzuki · lore

[PATCH v3 3/5] remote-curl: define struct for CURLOPT_WRITEFUNCTION

In order to pass more values for rpc_in, define a struct and pass it as an additional value.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 remote-curl.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)
Show changes to remote-curl.c +14 −4
diff --git a/remote-curl.c b/remote-curl.c
index d8eda2380a..d4673b6e8c 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -545,14 +545,22 @@ static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
 }
 #endif
 
+struct rpc_in_data {
+	struct rpc_state *rpc;
+};
+
+/*
+ * A callback for CURLOPT_WRITEFUNCTION. The return value is the bytes consumed
+ * from ptr.
+ */
 static size_t rpc_in(char *ptr, size_t eltsize,
 		size_t nmemb, void *buffer_)
 {
 	size_t size = eltsize * nmemb;
-	struct rpc_state *rpc = buffer_;
+	struct rpc_in_data *data = buffer_;
 	if (size)
-		rpc->any_written = 1;
-	write_or_die(rpc->in, ptr, size);
+		data->rpc->any_written = 1;
+	write_or_die(data->rpc->in, ptr, size);
 	return size;
 }
 
@@ -632,6 +640,7 @@ static int post_rpc(struct rpc_state *rpc)
 	size_t gzip_size = 0;
 	int err, large_request = 0;
 	int needs_100_continue = 0;
+	struct rpc_in_data rpc_in_data;
 
 	/* Try to load the entire request, if we can fit it into the
 	 * allocated buffer space we can use HTTP/1.0 and avoid the
@@ -764,7 +773,8 @@ static int post_rpc(struct rpc_state *rpc)
 
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
+	rpc_in_data.rpc = rpc;
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
 
 
 	rpc->any_written = 0;
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 8, 2019, 02:47 UTC · re: Masaya Suzuki · lore

[PATCH v3 4/5] remote-curl: unset CURLOPT_FAILONERROR

By not setting CURLOPT_FAILONERROR, curl parses the HTTP response headers even if the response is an error. This makes GIT_CURL_VERBOSE to show the HTTP headers, which is useful for debugging.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 remote-curl.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
Show changes to remote-curl.c +10 −0
diff --git a/remote-curl.c b/remote-curl.c
index d4673b6e8c..91b39ca098 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -547,6 +547,7 @@ static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
 
 struct rpc_in_data {
 	struct rpc_state *rpc;
+	struct active_request_slot *slot;
 };
 
 /*
@@ -558,6 +559,13 @@ static size_t rpc_in(char *ptr, size_t eltsize,
 {
 	size_t size = eltsize * nmemb;
 	struct rpc_in_data *data = buffer_;
+	long response_code;
+
+	if (curl_easy_getinfo(data->slot->curl, CURLINFO_RESPONSE_CODE,
+			      &response_code) != CURLE_OK)
+		return size;
+	if (response_code >= 300)
+		return size;
 	if (size)
 		data->rpc->any_written = 1;
 	write_or_die(data->rpc->in, ptr, size);
@@ -774,7 +782,9 @@ static int post_rpc(struct rpc_state *rpc)
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
 	rpc_in_data.rpc = rpc;
+	rpc_in_data.slot = slot;
 	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
+	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 
 
 	rpc->any_written = 0;
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 8, 2019, 02:47 UTC · re: Masaya Suzuki · lore

[PATCH v3 5/5] test: test GIT_CURL_VERBOSE=1 shows an error

This tests GIT_CURL_VERBOSE shows an error when an URL returns 500. This exercises the code in remote_curl.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 t/lib-httpd/apache.conf      |  1 +
 t/t5581-http-curl-verbose.sh | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100755 t/t5581-http-curl-verbose.sh
Show changes to 2 files +29 −0

t/lib-httpd/apache.conf, t/t5581-http-curl-verbose.sh

diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 581c010d8f..cc4b87507e 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -115,6 +115,7 @@ Alias /auth/dumb/ www/auth/dumb/
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
 </LocationMatch>
+ScriptAliasMatch /error_git_upload_pack/(.*)/git-upload-pack error.sh/
 ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
 ScriptAlias /broken_smart/ broken-smart-http.sh/
 ScriptAlias /error/ error.sh/
diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
new file mode 100755
index 0000000000..cd9283eeec
--- /dev/null
+++ b/t/t5581-http-curl-verbose.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+test_description='test GIT_CURL_VERBOSE'
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'setup repository' '
+	mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" --bare init &&
+	git config push.default matching &&
+	echo content >file &&
+	git add file &&
+	git commit -m one &&
+	git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git push public master:master
+'
+
+test_expect_success 'failure in git-upload-pack is shown' '
+	test_might_fail env GIT_CURL_VERBOSE=1 \
+		git clone "$HTTPD_URL/error_git_upload_pack/smart/repo.git" \
+		2>curl_log &&
+	grep "< HTTP/1.1 500 Intentional Breakage" curl_log
+'
+
+stop_httpd
+
+test_done
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 10, 2019, 19:33 UTC · re: Masaya Suzuki · lore

[PATCH v4 0/5] Show HTTP headers of failed requests with GIT_CURL_VERBOSE

Diff from v3[1]:
*   Handle ftruncate and fflush return values
*   Call rewind to set the position back
[1]: https://public-inbox.org/git/20190108024741.62176-1-masayasuzuki@google.com/
Masaya Suzuki (5):
  http: support file handles for HTTP_KEEP_ERROR
  http: enable keep_error for HTTP requests
  remote-curl: define struct for CURLOPT_WRITEFUNCTION
  remote-curl: unset CURLOPT_FAILONERROR
  test: test GIT_CURL_VERBOSE=1 shows an error
 http.c                       | 32 +++++++++++++++++++-------------
 http.h                       |  1 -
 remote-curl.c                | 29 ++++++++++++++++++++++++-----
 t/lib-httpd/apache.conf      |  1 +
 t/t5581-http-curl-verbose.sh | 28 ++++++++++++++++++++++++++++
 5 files changed, 72 insertions(+), 19 deletions(-)
 create mode 100755 t/t5581-http-curl-verbose.sh
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 10, 2019, 19:33 UTC · re: Masaya Suzuki · lore

[PATCH v4 1/5] http: support file handles for HTTP_KEEP_ERROR

HTTP_KEEP_ERROR makes it easy to debug HTTP transport errors. In order to make HTTP_KEEP_ERROR enabled for all requests, file handles need to be supported.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)
Show changes to http.c +13 −3
diff --git a/http.c b/http.c
index 0b6807cef9..4eccf4c5d8 100644
--- a/http.c
+++ b/http.c
@@ -1991,16 +1991,26 @@ static int http_request_reauth(const char *url,
 	/*
 	 * If we are using KEEP_ERROR, the previous request may have
 	 * put cruft into our output stream; we should clear it out before
-	 * making our next request. We only know how to do this for
-	 * the strbuf case, but that is enough to satisfy current callers.
+	 * making our next request.
 	 */
 	if (options && options->keep_error) {
 		switch (target) {
 		case HTTP_REQUEST_STRBUF:
 			strbuf_reset(result);
 			break;
+		case HTTP_REQUEST_FILE:
+			if (fflush(result)) {
+				error_errno("unable to flush a file");
+				return HTTP_START_FAILED;
+			}
+			rewind(result);
+			if (ftruncate(fileno(result), 0) < 0) {
+				error_errno("unable to truncate a file");
+				return HTTP_START_FAILED;
+			}
+			break;
 		default:
-			BUG("HTTP_KEEP_ERROR is only supported with strbufs");
+			BUG("Unknown http_request target");
 		}
 	}
 
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 10, 2019, 19:33 UTC · re: Masaya Suzuki · lore

[PATCH v4 2/5] http: enable keep_error for HTTP requests

curl stops parsing a response when it sees a bad HTTP status code and it has CURLOPT_FAILONERROR set. This prevents GIT_CURL_VERBOSE to show HTTP headers on error.

keep_error is an option to receive the HTTP response body for those error responses. By enabling this option, curl will process the HTTP response headers, and they're shown if GIT_CURL_VERBOSE is set.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 http.c        | 42 +++++++++++++++++++-----------------------
 http.h        |  1 -
 remote-curl.c |  1 -
 3 files changed, 19 insertions(+), 25 deletions(-)
Show changes to 3 files +19 −25

http.c, http.h, remote-curl.c

diff --git a/http.c b/http.c
index 4eccf4c5d8..954bebf684 100644
--- a/http.c
+++ b/http.c
@@ -1876,8 +1876,6 @@ static int http_request(const char *url,
 	strbuf_addstr(&buf, "Pragma:");
 	if (options && options->no_cache)
 		strbuf_addstr(&buf, " no-cache");
-	if (options && options->keep_error)
-		curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 	if (options && options->initial_request &&
 	    http_follow_config == HTTP_FOLLOW_INITIAL)
 		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
@@ -1895,6 +1893,7 @@ static int http_request(const char *url,
 	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "");
+	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 
 	ret = run_one_slot(slot, &results);
 
@@ -1989,29 +1988,26 @@ static int http_request_reauth(const char *url,
 		return ret;
 
 	/*
-	 * If we are using KEEP_ERROR, the previous request may have
-	 * put cruft into our output stream; we should clear it out before
-	 * making our next request.
+	 * The previous request may have put cruft into our output stream; we
+	 * should clear it out before making our next request.
 	 */
-	if (options && options->keep_error) {
-		switch (target) {
-		case HTTP_REQUEST_STRBUF:
-			strbuf_reset(result);
-			break;
-		case HTTP_REQUEST_FILE:
-			if (fflush(result)) {
-				error_errno("unable to flush a file");
-				return HTTP_START_FAILED;
-			}
-			rewind(result);
-			if (ftruncate(fileno(result), 0) < 0) {
-				error_errno("unable to truncate a file");
-				return HTTP_START_FAILED;
-			}
-			break;
-		default:
-			BUG("Unknown http_request target");
+	switch (target) {
+	case HTTP_REQUEST_STRBUF:
+		strbuf_reset(result);
+		break;
+	case HTTP_REQUEST_FILE:
+		if (fflush(result)) {
+			error_errno("unable to flush a file");
+			return HTTP_START_FAILED;
 		}
+		rewind(result);
+		if (ftruncate(fileno(result), 0) < 0) {
+			error_errno("unable to truncate a file");
+			return HTTP_START_FAILED;
+		}
+		break;
+	default:
+		BUG("Unknown http_request target");
 	}
 
 	credential_fill(&http_auth);
diff --git a/http.h b/http.h
index d305ca1dc7..eebf40688c 100644
--- a/http.h
+++ b/http.h
@@ -146,7 +146,6 @@ extern char *get_remote_object_url(const char *url, const char *hex,
 /* Options for http_get_*() */
 struct http_get_options {
 	unsigned no_cache:1,
-		 keep_error:1,
 		 initial_request:1;
 
 	/* If non-NULL, returns the content-type of the response. */
diff --git a/remote-curl.c b/remote-curl.c
index 1220dffcdc..d8eda2380a 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -380,7 +380,6 @@ static struct discovery *discover_refs(const char *service, int for_push)
 	http_options.extra_headers = &extra_headers;
 	http_options.initial_request = 1;
 	http_options.no_cache = 1;
-	http_options.keep_error = 1;
 
 	http_ret = http_get_strbuf(refs_url.buf, &buffer, &http_options);
 	switch (http_ret) {
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 10, 2019, 19:33 UTC · re: Masaya Suzuki · lore

[PATCH v4 3/5] remote-curl: define struct for CURLOPT_WRITEFUNCTION

In order to pass more values for rpc_in, define a struct and pass it as an additional value.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 remote-curl.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)
Show changes to remote-curl.c +14 −4
diff --git a/remote-curl.c b/remote-curl.c
index d8eda2380a..d4673b6e8c 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -545,14 +545,22 @@ static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
 }
 #endif
 
+struct rpc_in_data {
+	struct rpc_state *rpc;
+};
+
+/*
+ * A callback for CURLOPT_WRITEFUNCTION. The return value is the bytes consumed
+ * from ptr.
+ */
 static size_t rpc_in(char *ptr, size_t eltsize,
 		size_t nmemb, void *buffer_)
 {
 	size_t size = eltsize * nmemb;
-	struct rpc_state *rpc = buffer_;
+	struct rpc_in_data *data = buffer_;
 	if (size)
-		rpc->any_written = 1;
-	write_or_die(rpc->in, ptr, size);
+		data->rpc->any_written = 1;
+	write_or_die(data->rpc->in, ptr, size);
 	return size;
 }
 
@@ -632,6 +640,7 @@ static int post_rpc(struct rpc_state *rpc)
 	size_t gzip_size = 0;
 	int err, large_request = 0;
 	int needs_100_continue = 0;
+	struct rpc_in_data rpc_in_data;
 
 	/* Try to load the entire request, if we can fit it into the
 	 * allocated buffer space we can use HTTP/1.0 and avoid the
@@ -764,7 +773,8 @@ static int post_rpc(struct rpc_state *rpc)
 
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
-	curl_easy_setopt(slot->curl, CURLOPT_FILE, rpc);
+	rpc_in_data.rpc = rpc;
+	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
 
 
 	rpc->any_written = 0;
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 10, 2019, 19:33 UTC · re: Masaya Suzuki · lore

[PATCH v4 4/5] remote-curl: unset CURLOPT_FAILONERROR

By not setting CURLOPT_FAILONERROR, curl parses the HTTP response headers even if the response is an error. This makes GIT_CURL_VERBOSE to show the HTTP headers, which is useful for debugging.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 remote-curl.c | 10 ++++++++++
 1 file changed, 10 insertions(+)
Show changes to remote-curl.c +10 −0
diff --git a/remote-curl.c b/remote-curl.c
index d4673b6e8c..91b39ca098 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -547,6 +547,7 @@ static curlioerr rpc_ioctl(CURL *handle, int cmd, void *clientp)
 
 struct rpc_in_data {
 	struct rpc_state *rpc;
+	struct active_request_slot *slot;
 };
 
 /*
@@ -558,6 +559,13 @@ static size_t rpc_in(char *ptr, size_t eltsize,
 {
 	size_t size = eltsize * nmemb;
 	struct rpc_in_data *data = buffer_;
+	long response_code;
+
+	if (curl_easy_getinfo(data->slot->curl, CURLINFO_RESPONSE_CODE,
+			      &response_code) != CURLE_OK)
+		return size;
+	if (response_code >= 300)
+		return size;
 	if (size)
 		data->rpc->any_written = 1;
 	write_or_die(data->rpc->in, ptr, size);
@@ -774,7 +782,9 @@ static int post_rpc(struct rpc_state *rpc)
 	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
 	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, rpc_in);
 	rpc_in_data.rpc = rpc;
+	rpc_in_data.slot = slot;
 	curl_easy_setopt(slot->curl, CURLOPT_FILE, &rpc_in_data);
+	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
 
 
 	rpc->any_written = 0;
-- 
2.20.1.97.g81188d93c3-goog
Masaya Suzuki· Jan 10, 2019, 19:33 UTC · re: Masaya Suzuki · lore

[PATCH v4 5/5] test: test GIT_CURL_VERBOSE=1 shows an error

This tests GIT_CURL_VERBOSE shows an error when an URL returns 500. This exercises the code in remote_curl.

Signed-off-by: Masaya Suzuki <masayasuzuki@google.com>
---
 t/lib-httpd/apache.conf      |  1 +
 t/t5581-http-curl-verbose.sh | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+)
 create mode 100755 t/t5581-http-curl-verbose.sh
Show changes to 2 files +29 −0

t/lib-httpd/apache.conf, t/t5581-http-curl-verbose.sh

diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 581c010d8f..cc4b87507e 100644
--- a/t/lib-httpd/apache.conf
+++ b/t/lib-httpd/apache.conf
@@ -115,6 +115,7 @@ Alias /auth/dumb/ www/auth/dumb/
 	SetEnv GIT_EXEC_PATH ${GIT_EXEC_PATH}
 	SetEnv GIT_HTTP_EXPORT_ALL
 </LocationMatch>
+ScriptAliasMatch /error_git_upload_pack/(.*)/git-upload-pack error.sh/
 ScriptAliasMatch /smart_*[^/]*/(.*) ${GIT_EXEC_PATH}/git-http-backend/$1
 ScriptAlias /broken_smart/ broken-smart-http.sh/
 ScriptAlias /error/ error.sh/
diff --git a/t/t5581-http-curl-verbose.sh b/t/t5581-http-curl-verbose.sh
new file mode 100755
index 0000000000..cd9283eeec
--- /dev/null
+++ b/t/t5581-http-curl-verbose.sh
@@ -0,0 +1,28 @@
+#!/bin/sh
+
+test_description='test GIT_CURL_VERBOSE'
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-httpd.sh
+start_httpd
+
+test_expect_success 'setup repository' '
+	mkdir "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git -C "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" --bare init &&
+	git config push.default matching &&
+	echo content >file &&
+	git add file &&
+	git commit -m one &&
+	git remote add public "$HTTPD_DOCUMENT_ROOT_PATH/repo.git" &&
+	git push public master:master
+'
+
+test_expect_success 'failure in git-upload-pack is shown' '
+	test_might_fail env GIT_CURL_VERBOSE=1 \
+		git clone "$HTTPD_URL/error_git_upload_pack/smart/repo.git" \
+		2>curl_log &&
+	grep "< HTTP/1.1 500 Intentional Breakage" curl_log
+'
+
+stop_httpd
+
+test_done
-- 
2.20.1.97.g81188d93c3-goog
Junio C Hamano· Jan 10, 2019, 23:06 UTC · re: Masaya Suzuki · lore

Re: [PATCH v4 0/5] Show HTTP headers of failed requests with GIT_CURL_VERBOSE

Masaya Suzuki <masayasuzuki@google.com> writes:
Show 6 quoted lines
> Diff from v3[1]:
>
> *   Handle ftruncate and fflush return values
> *   Call rewind to set the position back
>
> [1]: https://public-inbox.org/git/20190108024741.62176-1-masayasuzuki@google.com/

Thanks. Adding the error checking even to 1/5 and moving the updated code in 2/5 makes the range-diff a bit noisy, but the resulting series makes lot of sense.

Will queue.
Show 15 quoted lines
>
> Masaya Suzuki (5):
>   http: support file handles for HTTP_KEEP_ERROR
>   http: enable keep_error for HTTP requests
>   remote-curl: define struct for CURLOPT_WRITEFUNCTION
>   remote-curl: unset CURLOPT_FAILONERROR
>   test: test GIT_CURL_VERBOSE=1 shows an error
>
>  http.c                       | 32 +++++++++++++++++++-------------
>  http.h                       |  1 -
>  remote-curl.c                | 29 ++++++++++++++++++++++++-----
>  t/lib-httpd/apache.conf      |  1 +
>  t/t5581-http-curl-verbose.sh | 28 ++++++++++++++++++++++++++++
>  5 files changed, 72 insertions(+), 19 deletions(-)
>  create mode 100755 t/t5581-http-curl-verbose.sh

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