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[PATCH 1/2] http: add option to enable 100 Continue responses

From
brian m. carlson <sandals@crustytoothpaste.net>
Date
Oct 8, 2013, 20:48 UTC
Message-ID
<1381265287-39331-2-git-send-email-sandals@crustytoothpaste.net>
In-Reply-To
<1381265287-39331-1-git-send-email-sandals@crustytoothpaste.net>

When using GSS-Negotiate authentication with libcurl, the authentication provided will change every time, and so the probe that git uses to determine if authentication is needed is not sufficient to guarantee that data can be sent. If the data fits entirely in http.postBuffer bytes, the data can be rewound and resent if authentication fails; otherwise, a 100 Continue must be requested in this case.

By default, curl will send an Expect: 100-continue if a certain amount of data is to be uploaded, but when using chunked data this is never triggered. Add an option http.continue, which defaults to enabled, to control whether this header is sent. The addition of an option is necessary because some proxies break badly if sent this header.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
---
 http.c        | 6 ++++++
 http.h        | 1 +
 remote-curl.c | 7 ++++++-
 3 files changed, 13 insertions(+), 1 deletion(-)
diff --git a/http.c b/http.c
index f3e1439..941c941 100644
--- a/http.c
+++ b/http.c
@@ -11,6 +11,7 @@
 int active_requests;
 int http_is_verbose;
 size_t http_post_buffer = 16 * LARGE_PACKET_MAX;
+int http_use_100_continue = 1;
 
 #if LIBCURL_VERSION_NUM >= 0x070a06
 #define LIBCURL_CAN_HANDLE_AUTH_ANY
@@ -213,6 +214,11 @@ static int http_options(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
+	if (!strcmp("http.continue", var)) {
+		http_use_100_continue = git_config_bool(var, value);
+		return 0;
+	}
+
 	if (!strcmp("http.useragent", var))
 		return git_config_string(&user_agent, var, value);
 
diff --git a/http.h b/http.h
index d77c1b5..e72786e 100644
--- a/http.h
+++ b/http.h
@@ -102,6 +102,7 @@ extern void http_cleanup(void);
 extern int active_requests;
 extern int http_is_verbose;
 extern size_t http_post_buffer;
+extern int http_use_100_continue;
 
 extern char curl_errorstr[CURL_ERROR_SIZE];
 
diff --git a/remote-curl.c b/remote-curl.c
index b5ebe01..3b5e160 100644
--- a/remote-curl.c
+++ b/remote-curl.c
@@ -470,7 +470,12 @@ static int post_rpc(struct rpc_state *rpc)
 
 	headers = curl_slist_append(headers, rpc->hdr_content_type);
 	headers = curl_slist_append(headers, rpc->hdr_accept);
-	headers = curl_slist_append(headers, "Expect:");
+
+	/* Force it either on or off, since curl will try to decide based on how
+	 * much data is to be uploaded and we want consistency.
+	 */
+	headers = curl_slist_append(headers, http_use_100_continue ?
+		"Expect: 100-continue" : "Expect:");
 
 retry:
 	slot = get_active_slot();
-- 
1.8.4.rc3
Previous: brian m. carlsonNext: Jeff King
Message 2 of 11 in “HTTP GSS-Negotiate improvements”
  1. 0/2 HTTP GSS-Negotiate improvementsbrian m. carlson, Oct 8, 2013
  2. 1/2 http: add option to enable 100 Continue responsesbrian m. carlson, Oct 8, 2013
  3. Jeff KingOct 9, 2013
  4. Shawn PearceOct 9, 2013
  5. Jeff KingOct 9, 2013
  6. brian m. carlsonOct 10, 2013
  7. Jeff KingOct 10, 2013
  8. Shawn PearceOct 10, 2013
  9. brian m. carlsonOct 11, 2013
  10. Shawn PearceOct 12, 2013
  11. 2/2 Update documentation for http.continue optionbrian m. carlson, Oct 8, 2013

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