merge: fix incorrect merge message for ambiguous tag/branch

If we have both a tag and a branch named "foo", then calling
"git merge foo" will warn about the ambiguous ref, but merge
the tag.

When generating the commit message, though, we simply
checked whether "refs/heads/foo" existed, and if it did,
assumed it was a branch. This led to the statement "Merge
branch 'foo'" in the commit message, which is quite wrong.

Instead, we should use dwim_ref to find the actual ref used,
and describe it appropriately.

In addition to the test in t7608, we must also tweak the
expected output of t4202, which was accidentally triggering
this bug.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin-merge.c b/builtin-merge.c
index 82b546689c500649285ea2c7825171f572c3758e..f7db14846ecbca6b0f928237951d9505b68e5d6a 100644 (file)
--- a/builtin-merge.c
+++ b/builtin-merge.c
@@ -358,6 +358,7 @@ static void merge_name(const char *remote, struct strbuf *msg)
        struct strbuf buf = STRBUF_INIT;
        struct strbuf bname = STRBUF_INIT;
        const char *ptr;
+       char *found_ref;
        int len, early;
 
        strbuf_branchname(&bname, remote);
@@ -368,14 +369,12 @@ static void merge_name(const char *remote, struct strbuf *msg)
        if (!remote_head)
                die("'%s' does not point to a commit", remote);
 
-       strbuf_addstr(&buf, "refs/heads/");
-       strbuf_addstr(&buf, remote);
-       resolve_ref(buf.buf, branch_head, 0, NULL);
-
-       if (!hashcmp(remote_head->sha1, branch_head)) {
-               strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
-                       sha1_to_hex(branch_head), remote);
-               goto cleanup;
+       if (dwim_ref(remote, strlen(remote), branch_head, &found_ref) > 0) {
+               if (!prefixcmp(found_ref, "refs/heads/")) {
+                       strbuf_addf(msg, "%s\t\tbranch '%s' of .\n",
+                                   sha1_to_hex(branch_head), remote);
+                       goto cleanup;
+               }
        }
 
        /* See if remote matches <name>^^^.. or <name>~<number> */

diff --git a/t/t4202-log.sh b/t/t4202-log.sh
index 48e0088b4780e133a450aea01092d9238e7122e9..1e952ca55b1ff146000153d720f11d1b7fa22707 100755 (executable)
--- a/t/t4202-log.sh
+++ b/t/t4202-log.sh
@@ -320,11 +320,11 @@ test_expect_success 'set up more tangled history' '
 '
 
 cat > expect <<\EOF
-*   Merge branch 'reach'
+*   Merge commit 'reach'
 |\
 | \
 |  \
-*-. \   Merge branches 'octopus-a' and 'octopus-b'
+*-. \   Merge commit 'octopus-a'; commit 'octopus-b'
 |\ \ \
 * | | | seventh
 | | * | octopus-b

diff --git a/t/t7608-merge-messages.sh b/t/t7608-merge-messages.sh
index 9d10583916d42092eaee29fbcafc73b1c827773b..81ced8ac3cc924a8461196cb71d27e9fc3a8f610 100755 (executable)
--- a/t/t7608-merge-messages.sh
+++ b/t/t7608-merge-messages.sh
@@ -38,7 +38,7 @@ test_expect_success 'merge tag' '
        check_oneline "Merge commit Qtag-1Q"
 '
 
-test_expect_failure 'ambiguous tag' '
+test_expect_success 'ambiguous tag' '
        git checkout -b ambiguous master &&
        test_commit ambiguous &&
        git checkout master &&