path.c: implement xdg_config_home()

diff --git a/cache.h b/cache.h
index 22b7b8129072f3905c68f02fe19f463bdb738b9e..2cb5371ac213b04bb575cb0dd92f907af18d1d4b 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -65,13 +65,6 @@ unsigned long git_deflate_bound(git_zstream *, unsigned long);
  *
  * The value 0160000 is not normally a valid mode, and
  * also just happens to be S_IFDIR + S_IFLNK
- *
- * NOTE! We *really* shouldn't depend on the S_IFxxx macros
- * always having the same values everywhere. We should use
- * our internal git values for these things, and then we can
- * translate that to the OS-specific value. It just so
- * happens that everybody shares the same bit representation
- * in the UNIX world (and apparently wider too..)
  */
 #define S_IFGITLINK    0160000
 #define S_ISGITLINK(m) (((m) & S_IFMT) == S_IFGITLINK)
@@ -835,6 +828,13 @@ char *strip_path_suffix(const char *path, const char *suffix);
 int daemon_avoid_alias(const char *path);
 extern int is_ntfs_dotgit(const char *name);
 
+/**
+ * Return a newly allocated string with the evaluation of
+ * "$XDG_CONFIG_HOME/git/$filename" if $XDG_CONFIG_HOME is non-empty, otherwise
+ * "$HOME/.config/git/$filename". Return NULL upon error.
+ */
+extern char *xdg_config_home(const char *filename);
+
 /* object replacement */
 #define LOOKUP_REPLACE_OBJECT 1
 extern void *read_sha1_file_extended(const unsigned char *sha1, enum object_type *type, unsigned long *size, unsigned flag);