setup: introduce the discover_git_directory() function

diff --git a/cache.h b/cache.h
index 61fc86e6d7199518555632a0b0b584471b9083a8..3cba58e219ba58834b83881715b3b699d3bc4af5 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -518,6 +518,13 @@ extern void set_git_work_tree(const char *tree);
 #define ALTERNATE_DB_ENVIRONMENT "GIT_ALTERNATE_OBJECT_DIRECTORIES"
 
 extern void setup_work_tree(void);
+/*
+ * Find GIT_DIR of the repository that contains the current working directory,
+ * without changing the working directory or other global state. The result is
+ * appended to gitdir. The return value is either NULL if no repository was
+ * found, or pointing to the path inside gitdir's buffer.
+ */
+extern const char *discover_git_directory(struct strbuf *gitdir);
 extern const char *setup_git_directory_gently(int *);
 extern const char *setup_git_directory(void);
 extern char *prefix_path(const char *prefix, int len, const char *path);