[PATCH 4/5] fix memory leak parsing core.commentchar

[Jeff King <peff@peff.net>]

When we see the core.commentchar config option, we extract
the string with git_config_string, which does two things:

  1. It complains via config_error_nonbool if there is no
     string value.

  2. It makes a copy of the string.

Since we immediately parse the string into its
single-character value, we only care about (1). And in fact
(2) is a detriment, as it means we leak the copy. Instead,
let's just check the pointer value ourselves, and parse
directly from the const string we already have.

Signed-off-by: Jeff King <peff@peff.net>
---
 config.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

diff --git a/config.c b/config.c
index 9767c4b..058505c 100644
--- a/config.c
+++ b/config.c
@@ -817,14 +817,12 @@ static int git_default_core_config(const char *var, const char *value)
 		return git_config_string(&editor_program, var, value);
 
 	if (!strcmp(var, "core.commentchar")) {
-		const char *comment;
-		int ret = git_config_string(&comment, var, value);
-		if (ret)
-			return ret;
-		else if (!strcasecmp(comment, "auto"))
+		if (!value)
+			return config_error_nonbool(var);
+		else if (!strcasecmp(value, "auto"))
 			auto_comment_line_char = 1;
-		else if (comment[0] && !comment[1]) {
-			comment_line_char = comment[0];
+		else if (value[0] && !value[1]) {
+			comment_line_char = value[0];
 			auto_comment_line_char = 0;
 		} else
 			return error("core.commentChar should only be one character");
-- 
2.0.0.566.gfe3e6b2