git-clone --reference: work well with pack-ref'ed reference repository

Earlier we only used loose refs to anchor already existing
objects.  When cloning from a repository that forked relatively
long time ago from the reference repository, this made the
want/have exchange by fetch-pack to do unnecessary work.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git-clone.sh b/git-clone.sh
index 171099674d1d89f5017dc77787c1fbff96154743..1bd54ded3c424db30ca46b00b3ed42b4d774d21d 100755 (executable)
--- a/git-clone.sh
+++ b/git-clone.sh
@@ -178,46 +178,32 @@ esac && export GIT_DIR && git-init ${template+"$template"} || usage
 
 if test -n "$reference"
 then
+       ref_git=
        if test -d "$reference"
        then
                if test -d "$reference/.git/objects"
                then
-                       reference="$reference/.git"
+                       ref_git="$reference/.git"
+               elif test -d "$reference/objects"
+               then
+                       ref_git="$reference"
                fi
-               reference=$(cd "$reference" && pwd)
-               echo "$reference/objects" >"$GIT_DIR/objects/info/alternates"
-               (cd "$reference" && tar cf - refs) |
-               (cd "$GIT_DIR/refs" &&
-                mkdir reference-tmp &&
-                cd reference-tmp &&
-                tar xf - &&
-                find refs ! -type d -print |
-                while read ref
-                do
-                       if test -h "$ref"
-                       then
-                               # Old-style symbolic link ref.  Not likely
-                               # to appear under refs/ but we might as well
-                               # deal with them.
-                               :
-                       elif test -f "$ref"
-                       then
-                               point=$(cat "$ref") &&
-                                       case "$point" in
-                                       'ref: '*) ;;
-                                       *) continue ;;
-                                       esac
-                       fi
-                       # The above makes true ref to 'continue' and
-                       # we will come here when we are looking at
-                       # symbolic link ref or a textual symref (or
-                       # garbage, like fifo).
-                       # The true ref pointed at by it is enough to
-                       # ensure that we do not fetch objects reachable
-                       # from it.
-                       rm -f "$ref"
-                done
-               )
+       fi
+       if test -n "$ref_git"
+       then
+               ref_git=$(cd "$ref_git" && pwd)
+               echo "$ref_git/objects" >"$GIT_DIR/objects/info/alternates"
+               (
+                       GIT_DIR="$ref_git" git for-each-ref \
+                               --format='%(objectname) %(*objectname)'
+               ) |
+               while read a b
+               do
+                       test -z "$a" ||
+                       git update-ref "refs/reference-tmp/$a" "$a"
+                       test -z "$b" ||
+                       git update-ref "refs/reference-tmp/$b" "$b"
+               done
        else
                die "reference repository '$reference' is not a local directory."
        fi