Re: git-merge fails when trying to merge from a tag

From: Junio C Hamano <junkio@cox.net>
Date: Dec 13, 2005, 19:21 UTC
Message-ID: <7vy82o951s.fsf@assigned-by-dhcp.cox.net>
In-Reply-To: <20051213175516.GA3695@hpsvcnb.fc.hp.com>

Carl Baldwin <cnb@fc.hp.com> writes:

> I just tried to merge using a tag object.

Thanks for the report.

> % git merge "Merging release-0.3.1" HEAD refs/tags/release-0.3.1

Once I considered changing commit-tree to take any committish after -p, but thought the command is a low level primitive and the user should know what he is doing, but apparently, git-merge does not know what it is doing ;-).

In fact, I never use "merge" myself, and haven't noticed this breakage until now (you would notice that the Everyday document never talks about "git merge"). Instead, I always do this:

	$ git pull . tag release-0.3.1

But you are right. It is advertised as the end-user command and demonstrated in the tutorial.

How about this patch? I haven't looked at what (old) git-resolve and git-octopus commands do --- they may need similar parameter massaging.

-- >8 -- [PATCH] allow merging any committish

Although "git-merge" is advertised as the end-user level command (instead of being a "git-pull" backend), it was not prepared to take tag objects that point at commits and barfed when fed one. Sanitize the input while we validate them, for which we already have a loop.

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

diff --git a/git-merge.sh b/git-merge.sh
index a221daa..d25ae4b 100755
--- a/git-merge.sh
+++ b/git-merge.sh
@@ -97,11 +97,14 @@ head=$(git-rev-parse --verify "$1"^0) ||
 shift
 
 # All the rest are remote heads
+remoteheads=
 for remote
 do
-	git-rev-parse --verify "$remote"^0 >/dev/null ||
+	remotehead=$(git-rev-parse --verify "$remote"^0) ||
 	    die "$remote - not something we can merge"
+	remoteheads="${remoteheads}$remotehead "
 done
+set x $remoteheads ; shift
 
 case "$#" in
 1)