contrib/subtree: unwrap tag refs

Rob Mayoff · peff · commit 5d65fe312e22 · 2015-11-24T16:53:35.000-05:00
If a subtree was added using a tag ref, the tag ref is stored in the subtree commit message instead of the underlying commit's ref. To split or push subsequent changes to the subtree, the subtree command needs to unwrap the tag ref. This patch makes it do so. The problem was described in a message to the mailing list from Junio C Hamano dated 29 Apr 2014, with the subject "Re: git subtree issue in more recent versions". The archived message can be found at <http://comments.gmane.org/gmane.comp.version-control.git/247503>. Signed-off-by: Rob Mayoff <mayoff@dqd.com> Signed-off-by: Jeff King <peff@peff.net>
diff --git a/contrib/subtree/git-subtree.sh b/contrib/subtree/git-subtree.sh
@@ -245,7 +245,10 @@ find_latest_squash()
 		case "$a" in
 			START) sq="$b" ;;
 			git-subtree-mainline:) main="$b" ;;
-			git-subtree-split:) sub="$b" ;;
+			git-subtree-split:)
+				sub="$(git rev-parse "$b^0")" ||
+				    die "could not rev-parse split hash $b from commit $sq"
+				;;
 			END)
 				if [ -n "$sub" ]; then
 					if [ -n "$main" ]; then
@@ -278,7 +281,10 @@ find_existing_splits()
 		case "$a" in
 			START) sq="$b" ;;
 			git-subtree-mainline:) main="$b" ;;
-			git-subtree-split:) sub="$b" ;;
+			git-subtree-split:)
+				sub="$(git rev-parse "$b^0")" ||
+				    die "could not rev-parse split hash $b from commit $sq"
+				;;
 			END)
 				debug "  Main is: '$main'"
 				if [ -z "$main" -a -n "$sub" ]; then
