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[RFC PATCH] grep: fix bug when recursing with relative pathspec

From
BWBrandon Williams <bmwill@google.com>
Date
Mar 6, 2017, 23:07 UTC
Message-ID
<20170306230717.29095-1-bmwill@google.com>
In-Reply-To
<20170224235100.52627-1-bmwill@google.com>

When using the --recurse-submodules flag with a relative pathspec which includes "..", an error is produced inside the child process spawned for a submodule. When creating the pathspec struct in the child, the ".." is interpreted to mean "go up a directory" which causes an error stating that the path ".." is outside of the repository.

While it is true that ".." is outside the scope of the submodule, it is confusing to a user who originally invoked the command where ".." was indeed still inside the scope of the superproject. Since the child process launched for the submodule has some context that it is operating underneath a superproject, this error could be avoided.

This patch fixes the bug by passing the 'prefix' to the child process. Now each child process that works on a submodule has two points of reference to the superproject: (1) the 'super_prefix' which is the path from the root of the superproject down to root of the submodule and (2) the 'prefix' which is the path from the root of the superproject down to the directory where the user invoked the git command.

With these two pieces of information a child process can correctly interpret the pathspecs provided by the user as well as being able to properly format the its output relative to the directory the user invoked a git command from.

Signed-off-by: Brandon Williams <bmwill@google.com>
---

After taking a closer look at this bug I determined that I did a poor job at thinking of all the corner cases when implementing a recursive grep. As it turns out I think we really need to pass on the prefix information to the child process so that it has enough context to do path matching and to format its output. Unfortunately I don't know the best way to pass on this information without breaking other commands that rely on the GIT_PREFIX being overridden during discovery. Maybe we'll need to add in another env var to account for that? For the purposes of showing how to fix this bug while still getting the test suite to pass, I have git respect the GIT_PREFIX env var only if the super_prefix is set (which it should only be used in submodule operations at this point in time). Its a pretty hacky fix, so I'm up for other suggestions on how to properly pass on this information to the child process.

 builtin/grep.c                     | 39 ++++++++++++--------
 git.c                              |  2 --
 setup.c                            |  5 +++
 t/t7814-grep-recurse-submodules.sh | 73 ++++++++++++++++++++++++++++++++++++++
 4 files changed, 102 insertions(+), 17 deletions(-)
diff --git a/builtin/grep.c b/builtin/grep.c
index 2c727ef49..acecad0e0 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -310,10 +310,7 @@ static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 {
 	struct strbuf pathbuf = STRBUF_INIT;
 
-	if (opt->relative && opt->prefix_length) {
-		quote_path_relative(filename + tree_name_len, opt->prefix, &pathbuf);
-		strbuf_insert(&pathbuf, 0, filename, tree_name_len);
-	} else if (super_prefix) {
+	if (super_prefix) {
 		strbuf_add(&pathbuf, filename, tree_name_len);
 		strbuf_addstr(&pathbuf, super_prefix);
 		strbuf_addstr(&pathbuf, filename + tree_name_len);
@@ -321,6 +318,13 @@ static int grep_sha1(struct grep_opt *opt, const unsigned char *sha1,
 		strbuf_addstr(&pathbuf, filename);
 	}
 
+	if (opt->relative && opt->prefix_length) {
+		char *name = strbuf_detach(&pathbuf, NULL);
+		quote_path_relative(name + tree_name_len, opt->prefix, &pathbuf);
+		strbuf_insert(&pathbuf, 0, name, tree_name_len);
+		free(name);
+	}
+
 #ifndef NO_PTHREADS
 	if (num_threads) {
 		add_work(opt, GREP_SOURCE_SHA1, pathbuf.buf, path, sha1);
@@ -345,12 +349,14 @@ static int grep_file(struct grep_opt *opt, const char *filename)
 {
 	struct strbuf buf = STRBUF_INIT;
 
+	if (super_prefix)
+		strbuf_addstr(&buf, super_prefix);
+	strbuf_addstr(&buf, filename);
+
 	if (opt->relative && opt->prefix_length) {
-		quote_path_relative(filename, opt->prefix, &buf);
-	} else {
-		if (super_prefix)
-			strbuf_addstr(&buf, super_prefix);
-		strbuf_addstr(&buf, filename);
+		char *name = strbuf_detach(&buf, NULL);
+		quote_path_relative(name, opt->prefix, &buf);
+		free(name);
 	}
 
 #ifndef NO_PTHREADS
@@ -399,13 +405,12 @@ static void run_pager(struct grep_opt *opt, const char *prefix)
 }
 
 static void compile_submodule_options(const struct grep_opt *opt,
-				      const struct pathspec *pathspec,
+				      const char **argv,
 				      int cached, int untracked,
 				      int opt_exclude, int use_index,
 				      int pattern_type_arg)
 {
 	struct grep_pat *pattern;
-	int i;
 
 	if (recurse_submodules)
 		argv_array_push(&submodule_options, "--recurse-submodules");
@@ -523,9 +528,8 @@ static void compile_submodule_options(const struct grep_opt *opt,
 
 	/* Add Pathspecs */
 	argv_array_push(&submodule_options, "--");
-	for (i = 0; i < pathspec->nr; i++)
-		argv_array_push(&submodule_options,
-				pathspec->items[i].original);
+	for (; *argv; argv++)
+		argv_array_push(&submodule_options, *argv);
 }
 
 /*
@@ -549,6 +553,11 @@ static int grep_submodule_launch(struct grep_opt *opt,
 	prepare_submodule_repo_env(&cp.env_array);
 	argv_array_push(&cp.env_array, GIT_DIR_ENVIRONMENT);
 
+	if (opt->relative && opt->prefix_length)
+		argv_array_pushf(&cp.env_array, "%s=%s",
+				 GIT_PREFIX_ENVIRONMENT,
+				 opt->prefix);
+
 	/* Add super prefix */
 	argv_array_pushf(&cp.args, "--super-prefix=%s%s/",
 			 super_prefix ? super_prefix : "",
@@ -1206,7 +1215,7 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 
 	if (recurse_submodules) {
 		gitmodules_config();
-		compile_submodule_options(&opt, &pathspec, cached, untracked,
+		compile_submodule_options(&opt, argv + i, cached, untracked,
 					  opt_exclude, use_index,
 					  pattern_type_arg);
 	}
diff --git a/git.c b/git.c
index b367cf668..b05108afd 100644
--- a/git.c
+++ b/git.c
@@ -361,8 +361,6 @@ static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 	if (!help && get_super_prefix()) {
 		if (!(p->option & SUPPORT_SUPER_PREFIX))
 			die("%s doesn't support --super-prefix", p->cmd);
-		if (prefix)
-			die("can't use --super-prefix from a subdirectory");
 	}
 
 	if (!help && p->option & NEED_WORK_TREE)
diff --git a/setup.c b/setup.c
index 1b534a750..0de379319 100644
--- a/setup.c
+++ b/setup.c
@@ -936,10 +936,15 @@ static const char *setup_git_directory_gently_1(int *nongit_ok)
 const char *setup_git_directory_gently(int *nongit_ok)
 {
 	const char *prefix;
+	const char *env_prefix;
 
 	prefix = setup_git_directory_gently_1(nongit_ok);
+	env_prefix = getenv(GIT_PREFIX_ENVIRONMENT);
+
 	if (prefix)
 		setenv(GIT_PREFIX_ENVIRONMENT, prefix, 1);
+	else if (env_prefix && get_super_prefix())
+		prefix = env_prefix;
 	else
 		setenv(GIT_PREFIX_ENVIRONMENT, "", 1);
 
diff --git a/t/t7814-grep-recurse-submodules.sh b/t/t7814-grep-recurse-submodules.sh
index 67247a01d..d8ed3d64f 100755
--- a/t/t7814-grep-recurse-submodules.sh
+++ b/t/t7814-grep-recurse-submodules.sh
@@ -227,6 +227,79 @@ test_expect_success 'grep history with moved submoules' '
 	test_cmp expect actual
 '
 
+test_expect_success 'grep using relative path' '
+	test_when_finished "rm -rf parent sub" &&
+	git init sub &&
+	echo "foobar" >sub/file &&
+	git -C sub add file &&
+	git -C sub commit -m "add file" &&
+
+	git init parent &&
+	echo "foobar" >parent/file &&
+	git -C parent add file &&
+	mkdir parent/src &&
+	echo "foobar" >parent/src/file2 &&
+	git -C parent add src/file2 &&
+	git -C parent submodule add ../sub &&
+	git -C parent commit -m "add files and submodule" &&
+
+	# From top works
+	cat >expect <<-\EOF &&
+	file:foobar
+	src/file2:foobar
+	sub/file:foobar
+	EOF
+	git -C parent grep --recurse-submodules -e "foobar" >actual &&
+	test_cmp expect actual &&
+
+	# Relative path to top errors out
+	cat >expect <<-\EOF &&
+	../file:foobar
+	file2:foobar
+	../sub/file:foobar
+	EOF
+	git -C parent/src grep --recurse-submodules -e "foobar" -- .. >actual &&
+	test_cmp expect actual &&
+
+	# Relative path to submodule errors out
+	cat >expect <<-\EOF &&
+	../sub/file:foobar
+	EOF
+	git -C parent/src grep --recurse-submodules -e "foobar" -- ../sub >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'grep from a subdir' '
+	test_when_finished "rm -rf parent sub" &&
+	git init sub &&
+	echo "foobar" >sub/file &&
+	git -C sub add file &&
+	git -C sub commit -m "add file" &&
+
+	git init parent &&
+	mkdir parent/src &&
+	echo "foobar" >parent/src/file &&
+	git -C parent add src/file &&
+	git -C parent submodule add ../sub src/sub &&
+	git -C parent submodule add ../sub sub &&
+	git -C parent commit -m "add files and submodules" &&
+
+	cat >expect <<-\EOF &&
+	src/file:foobar
+	src/sub/file:foobar
+	sub/file:foobar
+	EOF
+	git -C parent grep --recurse-submodules -e "foobar" >actual &&
+	test_cmp expect actual &&
+
+	cat >expect <<-\EOF &&
+	file:foobar
+	sub/file:foobar
+	EOF
+	git -C parent/src grep --recurse-submodules -e "foobar" >actual &&
+	test_cmp expect actual
+'
+
 test_incompatible_with_recurse_submodules ()
 {
 	test_expect_success "--recurse-submodules and $1 are incompatible" "
-- 
2.12.0.rc1.440.g5b76565f74-goog
Previous: Brandon WilliamsNext: Brandon Williams
Message 15 of 48 in “recursing submodules with relative pathspec (grep and ls-files)”
  1. 0/5 recursing submodules with relative pathspec (grep and ls-files)Brandon Williams, Feb 24, 2017
  2. 1/5 grep: illustrate bug when recursing with relative pathspecBrandon Williams, Feb 24, 2017
  3. Duy NguyenFeb 26, 2017
  4. Brandon WilliamsFeb 27, 2017
  5. 2/5 pathspec: add PATHSPEC_FROMROOT flagBrandon Williams, Feb 24, 2017
  6. Stefan BellerFeb 25, 2017
  7. 3/5 grep: fix bug when recuring with relative pathspecBrandon Williams, Feb 24, 2017
  8. Junio C HamanoFeb 28, 2017
  9. Brandon WilliamsMar 2, 2017
  10. 5/5 ls-files: fix bug when recuring with relative pathspecBrandon Williams, Feb 24, 2017
  11. Junio C HamanoFeb 28, 2017
  12. Brandon WilliamsMar 2, 2017
  13. 4/5 ls-files: illustrate bug when recursing with relative pathspecBrandon Williams, Feb 24, 2017
  14. Brandon WilliamsFeb 27, 2017
  15. grep: fix bug when recursing with relative pathspecBrandon Williams, Mar 6, 2017
  16. 0/4 recursing submodules with relative pathspec (grep and ls-files)Brandon Williams, Mar 14, 2017
  17. 1/4 grep: fix help text typoBrandon Williams, Mar 14, 2017
  18. Stefan BellerMar 14, 2017
  19. Brandon WilliamsMar 15, 2017
  20. 2/4 setup: allow for prefix to be passed to git commandsBrandon Williams, Mar 14, 2017
  21. Johannes SchindelinMar 14, 2017
  22. Brandon WilliamsMar 14, 2017
  23. 3/4 grep: fix bug when recursing with relative pathspecBrandon Williams, Mar 14, 2017
  24. Stefan BellerMar 14, 2017
  25. 4/4 ls-files: fix bug when recursing with relative pathspecBrandon Williams, Mar 14, 2017
  26. Stefan BellerMar 14, 2017
  27. Brandon WilliamsMar 15, 2017
  28. 0/5 recursing submodules with relative pathspec (grep and ls-files)Brandon Williams, Mar 17, 2017
  29. 3/5 grep: fix bug when recursing with relative pathspecBrandon Williams, Mar 17, 2017
  30. Duy NguyenMar 21, 2017
  31. Junio C HamanoMar 21, 2017
  32. Brandon WilliamsMar 22, 2017
  33. 5/5 ls-files: fix bug when recursing with relative pathspecBrandon Williams, Mar 17, 2017
  34. 4/5 ls-files: fix typo in variable nameBrandon Williams, Mar 17, 2017
  35. 2/5 setup: allow for prefix to be passed to git commandsBrandon Williams, Mar 17, 2017
  36. Stefan BellerMar 17, 2017
  37. Junio C HamanoMar 17, 2017
  38. Brandon WilliamsMar 17, 2017
  39. Junio C HamanoMar 17, 2017
  40. Brandon WilliamsMar 17, 2017
  41. Junio C HamanoMar 17, 2017
  42. Brandon WilliamsMar 20, 2017
  43. Junio C HamanoMar 21, 2017
  44. Stefan BellerMar 28, 2017
  45. Brandon WilliamsMar 17, 2017
  46. Stefan BellerMar 17, 2017
  47. Brandon WilliamsMar 17, 2017
  48. 1/5 grep: fix help text typoBrandon Williams, Mar 17, 2017

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