Minor fixes for warnings and error propagation

include/git2/repository.h

@@ -418,7 +418,11 @@ GIT_EXTERN(int) git_repository_config(git_config **out, git_repository *repo);
  * Get a snapshot of the repository's configuration
  *
  * Convenience function to take a snapshot from the repository's
- * configuration.
+ * configuration.  The contents of this snapshot will not change,
+ * even if the underlying config files are modified.
+ *
+ * The configuration file must be freed once it's no longer
+ * being used by the user.
  *
  * @param out Pointer to store the loaded configuration
  * @param repo the repository

src/config_file.c

@@ -247,18 +247,15 @@ static int refcounted_strmap_alloc(refcounted_strmap **out)
 	int error;
 
 	map = git__calloc(1, sizeof(refcounted_strmap));
-	if (!map) {
-		giterr_set_oom();
-		return -1;
-	}
+	GITERR_CHECK_ALLOC(map);
 
 	git_atomic_set(&map->refcount, 1);
-	if ((error = git_strmap_alloc(&map->values)) < 0) {
-		git__free(map);
-		return error;
-	}
 
+	if ((error = git_strmap_alloc(&map->values)) < 0)
+		git__free(map);
+	else
 		*out = map;
+
 	return error;
 }
 

src/diff_driver.c

@@ -219,7 +219,7 @@ static int git_diff_driver_load(
 	git_diff_driver *drv = NULL;
 	size_t namelen = strlen(driver_name);
 	khiter_t pos;
-	git_config *cfg, *repo_cfg;
+	git_config *cfg;
 	git_buf name = GIT_BUF_INIT;
 	const git_config_entry *ce;
 	bool found_driver = false;

src/repository.c

@@ -627,10 +627,11 @@ int git_repository_config(git_config **out, git_repository *repo)
 
 int git_repository_config_snapshot(git_config **out, git_repository *repo)
 {
+	int error;
 	git_config *weak;
 
-	if (git_repository_config__weakptr(&weak, repo) < 0)
-		return -1;
+	if ((error = git_repository_config__weakptr(&weak, repo)) < 0)
+		return error;
 
 	return git_config_snapshot(out, weak);
 }