[PATCH 05/11] config: use git_config_string_dup() to fix leaky open coding

[Jeff King <peff@peff.net>]

These are cases which open-code the equivalent of git_config_string(),
but end up leaking the resulting value if the config value is seen
multiple times (because they never free an existing value). Using
git_config_string_dup() plug these potential leaks.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/help.c | 7 ++-----
 config.c       | 8 ++------
 merge-ll.c     | 5 +----
 3 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/builtin/help.c b/builtin/help.c
index dc1fbe2b98..1bdd2faee0 100644
--- a/builtin/help.c
+++ b/builtin/help.c
@@ -52,7 +52,7 @@ static enum help_action {
 	HELP_ACTION_CONFIG_SECTIONS_FOR_COMPLETION,
 } cmd_mode;
 
-static const char *html_path;
+static char *html_path;
 static int verbose = 1;
 static enum help_format help_format = HELP_FORMAT_NONE;
 static int exclude_guides;
@@ -407,10 +407,7 @@ static int git_help_config(const char *var, const char *value,
 		return 0;
 	}
 	if (!strcmp(var, "help.htmlpath")) {
-		if (!value)
-			return config_error_nonbool(var);
-		html_path = xstrdup(value);
-		return 0;
+		return git_config_string_dup(&html_path, var, value);
 	}
 	if (!strcmp(var, "man.viewer")) {
 		if (!value)
diff --git a/config.c b/config.c
index a0aa45abd5..c115e6d8c9 100644
--- a/config.c
+++ b/config.c
@@ -1575,12 +1575,8 @@ static int git_default_core_config(const char *var, const char *value,
 	if (!strcmp(var, "core.checkroundtripencoding"))
 		return git_config_string(&check_roundtrip_encoding, var, value);
 
-	if (!strcmp(var, "core.notesref")) {
-		if (!value)
-			return config_error_nonbool(var);
-		notes_ref_name = xstrdup(value);
-		return 0;
-	}
+	if (!strcmp(var, "core.notesref"))
+		return git_config_string_dup(&notes_ref_name, var, value);
 
 	if (!strcmp(var, "core.editor"))
 		return git_config_string(&editor_program, var, value);
diff --git a/merge-ll.c b/merge-ll.c
index bf1077ae09..660d9a3bd6 100644
--- a/merge-ll.c
+++ b/merge-ll.c
@@ -308,8 +308,6 @@ static int read_merge_config(const char *var, const char *value,
 		return git_config_string(&fn->description, var, value);
 
 	if (!strcmp("driver", key)) {
-		if (!value)
-			return config_error_nonbool(var);
 		/*
 		 * merge.<name>.driver specifies the command line:
 		 *
@@ -333,8 +331,7 @@ static int read_merge_config(const char *var, const char *value,
 		 * file named by %A, and signal that it has done with zero exit
 		 * status.
 		 */
-		fn->cmdline = xstrdup(value);
-		return 0;
+		return git_config_string_dup(&fn->cmdline, var, value);
 	}
 
 	if (!strcmp("recursive", key))
-- 
2.44.0.872.g288abe5b5b