From: Omar Polo <op@omarpolo.com>
Subject: Re: gitconfig: fix read/write out of bound
To: James Cook <falsifian@falsifian.org>
Cc: gameoftrees@openbsd.org
Date: Tue, 21 Feb 2023 09:20:33 +0100

James Cook <falsifian@falsifian.org> writes:
> got still emits a "syntax error" warning if my ~/.gitconfig has a
> comment line with whitespace before the initial #, but it seems to be
> harmless. Example .gitconfig triggering the error message:
> 
> [user]
> 	#comment
> 	name = James Cook
> 	email = falsifian@falsifian.org

This adjust the parser to look for comments after trimming the lines,
which makes such "indented" comments work.  It also adds a test case
for it.

There's a separate, but small, change that I'm bundling here and it's
to log gitconfig.c error to stderr instead that on stdout.

ok?

diff /home/op/w/gotd
commit - 45e6b2f427b11e0fc760c10ee96eae3a6a5f06e7
path + /home/op/w/gotd
blob - 836551957b7ea94b0769a73ed8ac1f103def1278
file + lib/gitconfig.c
--- lib/gitconfig.c
+++ lib/gitconfig.c
@@ -55,8 +55,8 @@
 #define LOG_DBG(x)
 #endif
 
-#define log_print printf
-#define log_error printf
+#define log_print(...) fprintf(stderr, __VA_ARGS__)
+#define log_error(...) fprintf(stderr, __VA_ARGS__)
 
 #ifdef GITCONFIG_DEBUG
 static void
@@ -222,10 +222,6 @@ conf_parse_line(char **section, struct got_gitconfig *
 	size_t	 i;
 	int	 j;
 
-	/* Lines starting with '#' or ';' are comments.  */
-	if (*line == '#' || *line == ';')
-		return NULL;
-
 	/* '[section]' parsing...  */
 	if (*line == '[') {
 		for (i = 1; i < sz; i++)
@@ -248,6 +244,10 @@ conf_parse_line(char **section, struct got_gitconfig *
 		sz--;
 	}
 
+	/* Lines starting with '#' or ';' are comments.  */
+	if (*line == '#' || *line == ';')
+		return NULL;
+
 	/* Deal with assignments.  */
 	for (i = 0; i < sz; i++)
 		if (line[i] == '=') {
blob - 62bcb9f3f02f060aa7096a6fd0d8eb9f6ded5382
file + regress/cmdline/commit.sh
--- regress/cmdline/commit.sh
+++ regress/cmdline/commit.sh
@@ -982,6 +982,9 @@ test_commit_gitconfig_author() {
 
 	# retry with spaces in the git config
 	ed -s "$testroot/repo/.git/config" <<EOF
+/^\[user/ a
+    # it's me!
+.
 ,s/	/    /g
 wq
 EOF
@@ -989,13 +992,24 @@ EOF
 
 	# unset in a subshell to avoid affecting our environment
 	(unset GOT_IGNORE_GITCONFIG && cd "$testroot/wt" && \
-		got commit -m 'test gitconfig author again' >/dev/null)
+		got commit -m 'test gitconfig author again' \
+		>/dev/null 2>$testroot/stderr)
 	ret=$?
 	if [ $ret -ne 0 ]; then
 		test_done "$testroot" "$ret"
 		return 1
 	fi
 
+	# shouldn't have triggered any parsing error
+	echo -n > $testroot/stderr.expected
+	cmp -s $testroot/stderr.expected $testroot/stderr
+	ret=$?
+	if [ $ret -ne 0 ]; then
+		diff -u $testroot/stderr.expected $testroot/stderr
+		test_done "$testroot" "$ret"
+		return 1
+	fi
+
 	(cd "$testroot/repo" && got log -l1 | grep ^from: > $testroot/stdout)
 	ret=$?
 	if [ $ret -ne 0 ]; then