clone: Allow repo using gitfile as a reference

Try reading gitfile files when processing --reference options to clone.
This will allow, among other things, using a submodule checked out with
a recent version of git as a reference repository without requiring the
user to have internal knowledge of submodule layout.

Signed-off-by: Aaron Schrab <aaron@schrab.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/clone.c b/builtin/clone.c
index 0a1e0bf5a4d54c2e8937a5dd0e36c033d3833aeb..58fee9874f0fea4ed52acf31f757268be5383267 100644 (file)
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -232,11 +232,21 @@ static void strip_trailing_slashes(char *dir)
 static int add_one_reference(struct string_list_item *item, void *cb_data)
 {
        char *ref_git;
+       const char *repo;
        struct strbuf alternate = STRBUF_INIT;
 
-       /* Beware: real_path() and mkpath() return static buffer */
+       /* Beware: read_gitfile(), real_path() and mkpath() return static buffer */
        ref_git = xstrdup(real_path(item->string));
-       if (is_directory(mkpath("%s/.git/objects", ref_git))) {
+
+       repo = read_gitfile(ref_git);
+       if (!repo)
+               repo = read_gitfile(mkpath("%s/.git", ref_git));
+       if (repo) {
+               free(ref_git);
+               ref_git = xstrdup(repo);
+       }
+
+       if (!repo && is_directory(mkpath("%s/.git/objects", ref_git))) {
                char *ref_git_git = mkpathdup("%s/.git", ref_git);
                free(ref_git);
                ref_git = ref_git_git;

diff --git a/t/t5700-clone-reference.sh b/t/t5700-clone-reference.sh
index 60f1552adef417b8d37ca4215be1e66627c37258..6537911a4300656706c995226b2f0444a760bae0 100755 (executable)
--- a/t/t5700-clone-reference.sh
+++ b/t/t5700-clone-reference.sh
@@ -185,4 +185,17 @@ test_expect_success 'fetch with incomplete alternates' '
        ! grep " want $tag_object" "$U.K"
 '
 
+test_expect_success 'clone using repo with gitfile as a reference' '
+       git clone --separate-git-dir=L A M &&
+       git clone --reference=M A N &&
+       echo "$base_dir/L/objects" >expected &&
+       test_cmp expected "$base_dir/N/.git/objects/info/alternates"
+'
+
+test_expect_success 'clone using repo pointed at by gitfile as reference' '
+       git clone --reference=M/.git A O &&
+       echo "$base_dir/L/objects" >expected &&
+       test_cmp expected "$base_dir/O/.git/objects/info/alternates"
+'
+
 test_done