dir: fix leak when parsing "status.showUntrackedFiles"

We use `repo_config_get_string()` to read "status.showUntrackedFiles"
from the config subsystem. This function allocates the result, but we
never free the result after parsing it.

The value never leaves the scope of the calling function, so refactor it
to instead use `repo_config_get_string_tmp()`, which does not hand over
ownership to the caller.

Signed-off-by: Patrick Steinhardt <[email protected]>
Signed-off-by: Taylor Blau <[email protected]>

Author: pks-t

dir.c

@@ -2872,14 +2872,14 @@ static void set_untracked_ident(struct untracked_cache *uc)
 static unsigned new_untracked_cache_flags(struct index_state *istate)
 {
 	struct repository *repo = istate->repo;
-	char *val;
+	const char *val;
 
 	/*
 	 * This logic is coordinated with the setting of these flags in
 	 * wt-status.c#wt_status_collect_untracked(), and the evaluation
 	 * of the config setting in commit.c#git_status_config()
 	 */
-	if (!repo_config_get_string(repo, "status.showuntrackedfiles", &val) &&
+	if (!repo_config_get_string_tmp(repo, "status.showuntrackedfiles", &val) &&
 	    !strcmp(val, "all"))
 		return 0;
 

t/t7063-status-untracked-cache.sh

@@ -5,6 +5,7 @@ test_description='test untracked cache'
 GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
 export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
 
+TEST_PASSES_SANITIZE_LEAK=true
 . ./test-lib.sh
 
 # On some filesystems (e.g. FreeBSD's ext2 and ufs) directory mtime