Add ~ expansion to global attributes and excludes

This adds ~/ prefix expansion for the value of core.attributesfile
and core.excludesfile, plus it fixes the fact that the attributes
cache was holding on to the string data from the config for a long
time (instead of making its own strdup) which could have caused a
problem if the config was refreshed.  Adds a test for the new
expansion capability.

2 files changed, 25 insertions, 12 deletions

diff --git a/src/attr.c b/src/attr.c
index 9fe4471f6..6cdff29f9 100644
--- a/src/attr.c
+++ b/src/attr.c
@@ -596,26 +596,33 @@ static int collect_attr_files(
 }
 
 static int attr_cache__lookup_path(
-	const char **out, git_config *cfg, const char *key, const char *fallback)
+	char **out, git_config *cfg, const char *key, const char *fallback)
 {
 	git_buf buf = GIT_BUF_INIT;
 	int error;
+	const char *cfgval = NULL;
 
-	if (!(error = git_config_get_string(out, cfg, key)))
-		return 0;
+	*out = NULL;
+
+	if (!(error = git_config_get_string(&cfgval, cfg, key))) {
+
+		/* expand leading ~/ as needed */
+		if (cfgval && cfgval[0] == '~' && cfgval[1] == '/' &&
+			!git_futils_find_global_file(&buf, &cfgval[2]))
+			*out = git_buf_detach(&buf);
+		else if (cfgval)
+			*out = git__strdup(cfgval);
 
-	if (error == GIT_ENOTFOUND) {
+	} else if (error == GIT_ENOTFOUND) {
 		giterr_clear();
 		error = 0;
 
 		if (!git_futils_find_xdg_file(&buf, fallback))
 			*out = git_buf_detach(&buf);
-		else
-			*out = NULL;
-
-		git_buf_free(&buf);
 	}
 
+	git_buf_free(&buf);
+
 	return error;
 }
 
@@ -696,6 +703,12 @@ void git_attr_cache_flush(
 
 	git_pool_clear(&cache->pool);
 
+	git__free(cache->cfg_attr_file);
+	cache->cfg_attr_file = NULL;
+
+	git__free(cache->cfg_excl_file);
+	cache->cfg_excl_file = NULL;
+
 	cache->initialized = 0;
 }
 
diff --git a/src/attrcache.h b/src/attrcache.h
index 12cec4bfb..077633b87 100644
--- a/src/attrcache.h
+++ b/src/attrcache.h
@@ -13,10 +13,10 @@
 typedef struct {
 	int initialized;
 	git_pool pool;
-	git_strmap *files;	/* hash path to git_attr_file of rules */
-	git_strmap *macros;	/* hash name to vector<git_attr_assignment> */
-	const char *cfg_attr_file; /* cached value of core.attributesfile */
-	const char *cfg_excl_file; /* cached value of core.excludesfile */
+	git_strmap *files;	 /* hash path to git_attr_file of rules */
+	git_strmap *macros;	 /* hash name to vector<git_attr_assignment> */
+	char *cfg_attr_file; /* cached value of core.attributesfile */
+	char *cfg_excl_file; /* cached value of core.excludesfile */
 } git_attr_cache;
 
 extern int git_attr_cache__init(git_repository *repo);