Correctly read xdr compatible %HOME%/.config/git/config config file

This file is not just read if the global config file (%HOME%/.gitconfig)
is not found, however, it is used everytime but with lower priority.

Signed-off-by: Sven Strickroth <email@cs-ware.de>

include/git2/config.h

@@ -61,6 +61,9 @@ typedef struct {
  * may be used on any `git_config` call to load the
  * global configuration file.
  *
+ * This method will not guess the path to the xdr compatible
+ * config file (.config/git/config).
+ *
  * @param global_config_path Buffer of GIT_PATH_MAX length to store the path
  * @return 0 if a global configuration file has been
  *	found. Its path will be stored in `buffer`.
@@ -68,6 +71,23 @@ typedef struct {
 GIT_EXTERN(int) git_config_find_global(char *global_config_path, size_t length);
 
 /**
+ * Locate the path to the global xdr compatible configuration file
+ *
+ * The xdr compatible configuration file is usually
+ * located in `$HOME/.config/git/config`.
+ *
+ * This method will try to guess the full path to that
+ * file, if the file exists. The returned path
+ * may be used on any `git_config` call to load the
+ * global configuration file.
+ *
+ * @param global_config_path Buffer of GIT_PATH_MAX length to store the path
+ * @return 0 if a global configuration file has been
+ *	found. Its path will be stored in `buffer`.
+ */
+GIT_EXTERN(int) git_config_find_xdr(char *global_config_path, size_t length);
+
+/**
  * Locate the path to the system configuration file
  *
  * If /etc/gitconfig doesn't exist, it will look for

src/config.c

@@ -451,8 +451,12 @@ int git_config_find_global_r(git_buf *path)
 {
 	int error = git_futils_find_global_file(path, GIT_CONFIG_FILENAME);
 
-	if (error == GIT_ENOTFOUND)
-		error = git_futils_find_global_file(path, GIT_CONFIG_FILENAME_ALT);
+	return error;
+}
+
+int git_config_find_xdr_r(git_buf *path)
+{
+	int error = git_futils_find_global_file(path, GIT_CONFIG_FILENAME_ALT);
 
 	return error;
 }

src/repository.c

@@ -445,6 +445,7 @@ static int load_config(
 	git_config **out,
 	git_repository *repo,
 	const char *global_config_path,
+	const char *xdr_config_path,
 	const char *system_config_path)
 {
 	git_buf config_path = GIT_BUF_INIT;
@@ -459,13 +460,18 @@ static int load_config(
 		&config_path, repo->path_repository, GIT_CONFIG_FILENAME_INREPO) < 0)
 		goto on_error;
 
-	if (git_config_add_file_ondisk(cfg, config_path.ptr, 3) < 0)
+	if (git_config_add_file_ondisk(cfg, config_path.ptr, 4) < 0)
 		goto on_error;
 
 	git_buf_free(&config_path);
 
 	if (global_config_path != NULL) {
-		if (git_config_add_file_ondisk(cfg, global_config_path, 2) < 0)
+		if (git_config_add_file_ondisk(cfg, global_config_path, 3) < 0)
+			goto on_error;
+	}
+
+	if (xdr_config_path != NULL) {
+		if (git_config_add_file_ondisk(cfg, xdr_config_path, 3) < 0)
 			goto on_error;
 	}
 
@@ -487,19 +493,23 @@ on_error:
 int git_repository_config__weakptr(git_config **out, git_repository *repo)
 {
 	if (repo->_config == NULL) {
-		git_buf global_buf = GIT_BUF_INIT, system_buf = GIT_BUF_INIT;
+		git_buf global_buf = GIT_BUF_INIT, xdr_buf = GIT_BUF_INIT, system_buf = GIT_BUF_INIT;
 		int res;
 
 		const char *global_config_path = NULL;
+		const char *xdr_config_path = NULL;
 		const char *system_config_path = NULL;
 
 		if (git_config_find_global_r(&global_buf) == 0)
 			global_config_path = global_buf.ptr;
 
+		if (git_config_find_xdr_r(&xdr_buf) == 0)
+			xdr_config_path = xdr_buf.ptr;
+
 		if (git_config_find_system_r(&system_buf) == 0)
 			system_config_path = system_buf.ptr;
 
-		res = load_config(&repo->_config, repo, global_config_path, system_config_path);
+		res = load_config(&repo->_config, repo, global_config_path, xdr_config_path, system_config_path);
 
 		git_buf_free(&global_buf);
 		git_buf_free(&system_buf);