create_symref: if symlink fails, fall back to writing a "symbolic ref"

There are filesystems out there which do not understand symlinks, even if
the OS is perfectly capable of writing them. So, do not fail right away,
but try to write a symbolic ref first. If that fails, you can die().

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/refs.c b/refs.c
index 97506a4ebdfbd164abad6be76d7160db171d9148..a52b038eefdf22fce20d1a81180c97def0613cdb 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -116,14 +116,17 @@ const char *resolve_ref(const char *path, unsigned char *sha1, int reading)
 
 int create_symref(const char *git_HEAD, const char *refs_heads_master)
 {
-#if USE_SYMLINK_HEAD
-       unlink(git_HEAD);
-       return symlink(refs_heads_master, git_HEAD);
-#else
        const char *lockpath;
        char ref[1000];
        int fd, len, written;
 
+#if USE_SYMLINK_HEAD
+       unlink(git_HEAD);
+       if (!symlink(refs_heads_master, git_HEAD))
+               return 0;
+       fprintf(stderr, "no symlink - falling back to symbolic ref\n");
+#endif
+
        len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
        if (sizeof(ref) <= len) {
                error("refname too long: %s", refs_heads_master);
@@ -144,7 +147,6 @@ int create_symref(const char *git_HEAD, const char *refs_heads_master)
                return -3;
        }
        return 0;
-#endif
 }
 
 int read_ref(const char *filename, unsigned char *sha1)