Merge branch 'jc/remote'

* jc/remote:
  git-push: Update description of refspecs and add examples
  remote.c: "git-push frotz" should update what matches at the source.
  remote.c: fix "git push" weak match disambiguation
  remote.c: minor clean-up of match_explicit()
  remote.c: refactor creation of new dst ref
  remote.c: refactor match_explicit_refs()

3 files changed, 275 insertions, 85 deletions

diff --git a/Documentation/git-push.txt b/Documentation/git-push.txt
index 366c5dbdce..665f6dc709 100644
--- a/Documentation/git-push.txt
+++ b/Documentation/git-push.txt
@@ -53,9 +53,8 @@ side are updated.
 +
 `tag <tag>` means the same as `refs/tags/<tag>:refs/tags/<tag>`.
 +
-A parameter <ref> without a colon is equivalent to
-<ref>`:`<ref>, hence updates <ref> in the destination from <ref>
-in the source.
+A parameter <ref> without a colon pushes the <ref> from the source
+repository to the destination repository under the same name.
 +
 Pushing an empty <src> allows you to delete the <dst> ref from
 the remote repository.
@@ -98,6 +97,26 @@ the remote repository.
 
 include::urls.txt[]
 
+
+Examples
+--------
+
+git push origin master::
+	Find a ref that matches `master` in the source repository
+	(most likely, it would find `refs/heads/master`), and update
+	the same ref (e.g. `refs/heads/master`) in `origin` repository
+	with it.
+
+git push origin :experimental::
+	Find a ref that matches `experimental` in the `origin` repository
+	(e.g. `refs/heads/experimental`), and delete it.
+
+git push origin master:satellite/master::
+	Find a ref that matches `master` in the source repository
+	(most likely, it would find `refs/heads/master`), and update
+	the ref that matches `satellite/master` (most likely, it would
+	be `refs/remotes/satellite/master`) in `origin` repository with it.
+
 Author
 ------
 Written by Junio C Hamano <junkio@cox.net>, later rewritten in C
diff --git a/remote.c b/remote.c
index 54c9401a6b..500ca4d968 100644
--- a/remote.c
+++ b/remote.c
@@ -333,7 +333,6 @@ static int count_refspec_match(const char *pattern,
 	for (weak_match = match = 0; refs; refs = refs->next) {
 		char *name = refs->name;
 		int namelen = strlen(name);
-		int weak_match;
 
 		if (namelen < patlen ||
 		    memcmp(name + namelen - patlen, pattern, patlen))
@@ -406,90 +405,96 @@ static struct ref *try_explicit_object_name(const char *name)
 	return ref;
 }
 
-static int match_explicit_refs(struct ref *src, struct ref *dst,
-			       struct ref ***dst_tail, struct refspec *rs,
-			       int rs_nr)
+static struct ref *make_dst(const char *name, struct ref ***dst_tail)
 {
-	int i, errs;
-	for (i = errs = 0; i < rs_nr; i++) {
-		struct ref *matched_src, *matched_dst;
+	struct ref *dst;
+	size_t len;
 
-		const char *dst_value = rs[i].dst;
+	len = strlen(name) + 1;
+	dst = xcalloc(1, sizeof(*dst) + len);
+	memcpy(dst->name, name, len);
+	link_dst_tail(dst, dst_tail);
+	return dst;
+}
 
-		if (rs[i].pattern)
-			continue;
+static int match_explicit(struct ref *src, struct ref *dst,
+			  struct ref ***dst_tail,
+			  struct refspec *rs,
+			  int errs)
+{
+	struct ref *matched_src, *matched_dst;
 
-		if (dst_value == NULL)
-			dst_value = rs[i].src;
+	const char *dst_value = rs->dst;
 
-		matched_src = matched_dst = NULL;
-		switch (count_refspec_match(rs[i].src, src, &matched_src)) {
-		case 1:
-			break;
-		case 0:
-			/* The source could be in the get_sha1() format
-			 * not a reference name.  :refs/other is a
-			 * way to delete 'other' ref at the remote end.
-			 */
-			matched_src = try_explicit_object_name(rs[i].src);
-			if (matched_src)
-				break;
-			errs = 1;
-			error("src refspec %s does not match any.",
-			      rs[i].src);
-			break;
-		default:
-			errs = 1;
-			error("src refspec %s matches more than one.",
-			      rs[i].src);
-			break;
-		}
-		switch (count_refspec_match(dst_value, dst, &matched_dst)) {
-		case 1:
-			break;
-		case 0:
-			if (!memcmp(dst_value, "refs/", 5)) {
-				int len = strlen(dst_value) + 1;
-				matched_dst = xcalloc(1, sizeof(*dst) + len);
-				memcpy(matched_dst->name, dst_value, len);
-				link_dst_tail(matched_dst, dst_tail);
-			}
-			else if (!strcmp(rs[i].src, dst_value) &&
-				 matched_src) {
-				/* pushing "master:master" when
-				 * remote does not have master yet.
-				 */
-				int len = strlen(matched_src->name) + 1;
-				matched_dst = xcalloc(1, sizeof(*dst) + len);
-				memcpy(matched_dst->name, matched_src->name,
-				       len);
-				link_dst_tail(matched_dst, dst_tail);
-			}
-			else {
-				errs = 1;
-				error("dst refspec %s does not match any "
-				      "existing ref on the remote and does "
-				      "not start with refs/.", dst_value);
-			}
-			break;
-		default:
-			errs = 1;
-			error("dst refspec %s matches more than one.",
-			      dst_value);
+	if (rs->pattern)
+		return errs;
+
+	matched_src = matched_dst = NULL;
+	switch (count_refspec_match(rs->src, src, &matched_src)) {
+	case 1:
+		break;
+	case 0:
+		/* The source could be in the get_sha1() format
+		 * not a reference name.  :refs/other is a
+		 * way to delete 'other' ref at the remote end.
+		 */
+		matched_src = try_explicit_object_name(rs->src);
+		if (matched_src)
 			break;
-		}
-		if (errs)
-			continue;
-		if (matched_dst->peer_ref) {
-			errs = 1;
-			error("dst ref %s receives from more than one src.",
-			      matched_dst->name);
-		}
-		else {
-			matched_dst->peer_ref = matched_src;
-			matched_dst->force = rs[i].force;
-		}
+		error("src refspec %s does not match any.",
+		      rs->src);
+		break;
+	default:
+		matched_src = NULL;
+		error("src refspec %s matches more than one.",
+		      rs->src);
+		break;
+	}
+
+	if (!matched_src)
+		errs = 1;
+
+	if (dst_value == NULL)
+		dst_value = matched_src->name;
+
+	switch (count_refspec_match(dst_value, dst, &matched_dst)) {
+	case 1:
+		break;
+	case 0:
+		if (!memcmp(dst_value, "refs/", 5))
+			matched_dst = make_dst(dst_value, dst_tail);
+		else
+			error("dst refspec %s does not match any "
+			      "existing ref on the remote and does "
+			      "not start with refs/.", dst_value);
+		break;
+	default:
+		matched_dst = NULL;
+		error("dst refspec %s matches more than one.",
+		      dst_value);
+		break;
+	}
+	if (errs || matched_dst == NULL)
+		return 1;
+	if (matched_dst->peer_ref) {
+		errs = 1;
+		error("dst ref %s receives from more than one src.",
+		      matched_dst->name);
+	}
+	else {
+		matched_dst->peer_ref = matched_src;
+		matched_dst->force = rs->force;
 	}
+	return errs;
+}
+
+static int match_explicit_refs(struct ref *src, struct ref *dst,
+			       struct ref ***dst_tail, struct refspec *rs,
+			       int rs_nr)
+{
+	int i, errs;
+	for (i = errs = 0; i < rs_nr; i++)
+		errs |= match_explicit(src, dst, dst_tail, &rs[i], errs);
 	return -errs;
 }
 
@@ -513,6 +518,11 @@ static const struct refspec *check_pattern_match(const struct refspec *rs,
 	return NULL;
 }
 
+/*
+ * Note. This is used only by "push"; refspec matching rules for
+ * push and fetch are subtly different, so do not try to reuse it
+ * without thinking.
+ */
 int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 	       int nr_refspec, char **refspec, int all)
 {
@@ -555,11 +565,8 @@ int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
 			goto free_name;
 		if (!dst_peer) {
 			/* Create a new one and link it */
-			int len = strlen(dst_name) + 1;
-			dst_peer = xcalloc(1, sizeof(*dst_peer) + len);
-			memcpy(dst_peer->name, dst_name, len);
+			dst_peer = make_dst(dst_name, dst_tail);
 			hashcpy(dst_peer->new_sha1, src->new_sha1);
-			link_dst_tail(dst_peer, dst_tail);
 		}
 		dst_peer->peer_ref = src;
 	free_name:
diff --git a/t/t5516-fetch-push.sh b/t/t5516-fetch-push.sh
index dba018f667..08d58e1c8c 100755
--- a/t/t5516-fetch-push.sh
+++ b/t/t5516-fetch-push.sh
@@ -15,12 +15,58 @@ mk_empty () {
 	)
 }
 
+mk_test () {
+	mk_empty &&
+	(
+		for ref in "$@"
+		do
+			git push testrepo $the_first_commit:refs/$ref || {
+				echo "Oops, push refs/$ref failure"
+				exit 1
+			}
+		done &&
+		cd testrepo &&
+		for ref in "$@"
+		do
+			r=$(git show-ref -s --verify refs/$ref) &&
+			test "z$r" = "z$the_first_commit" || {
+				echo "Oops, refs/$ref is wrong"
+				exit 1
+			}
+		done &&
+		git fsck --full
+	)
+}
+
+check_push_result () {
+	(
+		cd testrepo &&
+		it="$1" &&
+		shift
+		for ref in "$@"
+		do
+			r=$(git show-ref -s --verify refs/$ref) &&
+			test "z$r" = "z$it" || {
+				echo "Oops, refs/$ref is wrong"
+				exit 1
+			}
+		done &&
+		git fsck --full
+	)
+}
+
 test_expect_success setup '
 
 	: >path1 &&
 	git add path1 &&
 	test_tick &&
 	git commit -a -m repo &&
+	the_first_commit=$(git show-ref -s --verify refs/heads/master) &&
+
+	: >path2 &&
+	git add path2 &&
+	test_tick &&
+	git commit -a -m second &&
 	the_commit=$(git show-ref -s --verify refs/heads/master)
 
 '
@@ -79,4 +125,122 @@ test_expect_success 'push with wildcard' '
 	)
 '
 
+test_expect_success 'push with matching heads' '
+
+	mk_test heads/master &&
+	git push testrepo &&
+	check_push_result $the_commit heads/master
+
+'
+
+test_expect_success 'push with no ambiguity (1)' '
+
+	mk_test heads/master &&
+	git push testrepo master:master &&
+	check_push_result $the_commit heads/master
+
+'
+
+test_expect_success 'push with no ambiguity (2)' '
+
+	mk_test remotes/origin/master &&
+	git push testrepo master:master &&
+	check_push_result $the_commit remotes/origin/master
+
+'
+
+test_expect_success 'push with weak ambiguity (1)' '
+
+	mk_test heads/master remotes/origin/master &&
+	git push testrepo master:master &&
+	check_push_result $the_commit heads/master &&
+	check_push_result $the_first_commit remotes/origin/master
+
+'
+
+test_expect_success 'push with weak ambiguity (2)' '
+
+	mk_test heads/master remotes/origin/master remotes/another/master &&
+	git push testrepo master:master &&
+	check_push_result $the_commit heads/master &&
+	check_push_result $the_first_commit remotes/origin/master remotes/another/master
+
+'
+
+test_expect_success 'push with ambiguity (1)' '
+
+	mk_test remotes/origin/master remotes/frotz/master &&
+	if git push testrepo master:master
+	then
+		echo "Oops, should have failed"
+		false
+	else
+		check_push_result $the_first_commit remotes/origin/master remotes/frotz/master
+	fi
+'
+
+test_expect_success 'push with ambiguity (2)' '
+
+	mk_test heads/frotz tags/frotz &&
+	if git push testrepo master:frotz
+	then
+		echo "Oops, should have failed"
+		false
+	else
+		check_push_result $the_first_commit heads/frotz tags/frotz
+	fi
+
+'
+
+test_expect_success 'push with colon-less refspec (1)' '
+
+	mk_test heads/frotz tags/frotz &&
+	git branch -f frotz master &&
+	git push testrepo frotz &&
+	check_push_result $the_commit heads/frotz &&
+	check_push_result $the_first_commit tags/frotz
+
+'
+
+test_expect_success 'push with colon-less refspec (2)' '
+
+	mk_test heads/frotz tags/frotz &&
+	if git show-ref --verify -q refs/heads/frotz
+	then
+		git branch -D frotz
+	fi &&
+	git tag -f frotz &&
+	git push testrepo frotz &&
+	check_push_result $the_commit tags/frotz &&
+	check_push_result $the_first_commit heads/frotz
+
+'
+
+test_expect_success 'push with colon-less refspec (3)' '
+
+	mk_test &&
+	if git show-ref --verify -q refs/tags/frotz
+	then
+		git tag -d frotz
+	fi &&
+	git branch -f frotz master &&
+	git push testrepo frotz &&
+	check_push_result $the_commit heads/frotz &&
+	test "$( cd testrepo && git show-ref | wc -l )" = 1
+'
+
+test_expect_success 'push with colon-less refspec (4)' '
+
+	mk_test &&
+	if git show-ref --verify -q refs/heads/frotz
+	then
+		git branch -D frotz
+	fi &&
+	git tag -f frotz &&
+	git push testrepo frotz &&
+	check_push_result $the_commit tags/frotz &&
+	test "$( cd testrepo && git show-ref | wc -l )" = 1
+
+'
+
 test_done