clone: allow "--dissociate" without reference

The "--reference" option is not the only way to provide a repository
to borrow objects from.  A repository that borrows from another
repository can be cloned with "clone --local" and the resulting
repository will borrow from the same repository, which the user
may want to "--dissociate" from.

Signed-off-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-clone.txt b/Documentation/git-clone.txt
index f1f2a3f..6bf000d 100644 (file)
--- a/Documentation/git-clone.txt
+++ b/Documentation/git-clone.txt
@@ -104,8 +104,13 @@ objects from the source repository into a pack in the cloned repository.
 --dissociate::
        Borrow the objects from reference repositories specified
        with the `--reference` options only to reduce network
-       transfer and stop borrowing from them after a clone is made
-       by making necessary local copies of borrowed objects.
+       transfer, and stop borrowing from them after a clone is made
+       by making necessary local copies of borrowed objects.  This
+       option can also be used when cloning locally from a
+       repository that already borrows objects from another
+       repository--the new repository will borrow objects from the
+       same repository, and this option can be used to stop the
+       borrowing.
 
 --quiet::
 -q::

diff --git a/builtin/clone.c b/builtin/clone.c
index 9eaecd9..caae43e 100644 (file)
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -801,11 +801,15 @@ static void write_refspec_config(const char *src_ref_prefix,
 static void dissociate_from_references(void)
 {
        static const char* argv[] = { "repack", "-a", "-d", NULL };
+       char *alternates = git_pathdup("objects/info/alternates");
 
-       if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
-               die(_("cannot repack to clean up"));
-       if (unlink(git_path("objects/info/alternates")) && errno != ENOENT)
-               die_errno(_("cannot unlink temporary alternates file"));
+       if (!access(alternates, F_OK)) {
+               if (run_command_v_opt(argv, RUN_GIT_CMD|RUN_COMMAND_NO_STDIN))
+                       die(_("cannot repack to clean up"));
+               if (unlink(alternates) && errno != ENOENT)
+                       die_errno(_("cannot unlink temporary alternates file"));
+       }
+       free(alternates);
 }
 
 int cmd_clone(int argc, const char **argv, const char *prefix)
@@ -954,10 +958,6 @@ int cmd_clone(int argc, const char **argv, const char *prefix)
 
        if (option_reference.nr)
                setup_reference();
-       else if (option_dissociate) {
-               warning(_("--dissociate given, but there is no --reference"));
-               option_dissociate = 0;
-       }
 
        fetch_pattern = value.buf;
        refspec = parse_fetch_refspec(1, &fetch_pattern);

diff --git a/t/t5700-clone-reference.sh b/t/t5700-clone-reference.sh
index 2250ef4..dfa1bf7 100755 (executable)
--- a/t/t5700-clone-reference.sh
+++ b/t/t5700-clone-reference.sh
@@ -210,4 +210,15 @@ test_expect_success 'clone, dissociate from partial reference and repack' '
        test_line_count = 1 packs.txt
 '
 
+test_expect_success 'clone, dissociate from alternates' '
+       rm -fr A B C &&
+       test_create_repo A &&
+       commit_in A file1 &&
+       git clone --reference=A A B &&
+       test_line_count = 1 B/.git/objects/info/alternates &&
+       git clone --local --dissociate B C &&
+       ! test -f C/.git/objects/info/alternates &&
+       ( cd C && git fsck )
+'
+
 test_done