Merge branch 'jc/push-refmap'

Make "git push origin master" update the same ref that would be
updated by our 'master' when "git push origin" (no refspecs) is run
while the 'master' branch is checked out, which makes "git push"
more symmetric to "git fetch" and more usable for the triangular
workflow.

* jc/push-refmap:
  push: also use "upstream" mapping when pushing a single ref
  push: use remote.$name.push as a refmap
  builtin/push.c: use strbuf instead of manual allocation

1 files changed, 62 insertions, 22 deletions

diff --git a/builtin/push.c b/builtin/push.c
index a73982a308..0e50ddbb01 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -35,35 +35,75 @@ static void add_refspec(const char *ref)
 	refspec[refspec_nr-1] = ref;
 }
 
-static void set_refspecs(const char **refs, int nr)
+static const char *map_refspec(const char *ref,
+			       struct remote *remote, struct ref *local_refs)
 {
+	struct ref *matched = NULL;
+
+	/* Does "ref" uniquely name our ref? */
+	if (count_refspec_match(ref, local_refs, &matched) != 1)
+		return ref;
+
+	if (remote->push) {
+		struct refspec query;
+		memset(&query, 0, sizeof(struct refspec));
+		query.src = matched->name;
+		if (!query_refspecs(remote->push, remote->push_refspec_nr, &query) &&
+		    query.dst) {
+			struct strbuf buf = STRBUF_INIT;
+			strbuf_addf(&buf, "%s%s:%s",
+				    query.force ? "+" : "",
+				    query.src, query.dst);
+			return strbuf_detach(&buf, NULL);
+		}
+	}
+
+	if (push_default == PUSH_DEFAULT_UPSTREAM &&
+	    !prefixcmp(matched->name, "refs/heads/")) {
+		struct branch *branch = branch_get(matched->name + 11);
+		if (branch->merge_nr == 1 && branch->merge[0]->src) {
+			struct strbuf buf = STRBUF_INIT;
+			strbuf_addf(&buf, "%s:%s",
+				    ref, branch->merge[0]->src);
+			return strbuf_detach(&buf, NULL);
+		}
+	}
+
+	return ref;
+}
+
+static void set_refspecs(const char **refs, int nr, const char *repo)
+{
+	struct remote *remote = NULL;
+	struct ref *local_refs = NULL;
 	int i;
+
 	for (i = 0; i < nr; i++) {
 		const char *ref = refs[i];
 		if (!strcmp("tag", ref)) {
-			char *tag;
-			int len;
+			struct strbuf tagref = STRBUF_INIT;
 			if (nr <= ++i)
 				die(_("tag shorthand without <tag>"));
-			len = strlen(refs[i]) + 11;
-			if (deleterefs) {
-				tag = xmalloc(len+1);
-				strcpy(tag, ":refs/tags/");
-			} else {
-				tag = xmalloc(len);
-				strcpy(tag, "refs/tags/");
+			ref = refs[i];
+			if (deleterefs)
+				strbuf_addf(&tagref, ":refs/tags/%s", ref);
+			else
+				strbuf_addf(&tagref, "refs/tags/%s", ref);
+			ref = strbuf_detach(&tagref, NULL);
+		} else if (deleterefs) {
+			struct strbuf delref = STRBUF_INIT;
+			if (strchr(ref, ':'))
+				die(_("--delete only accepts plain target ref names"));
+			strbuf_addf(&delref, ":%s", ref);
+			ref = strbuf_detach(&delref, NULL);
+		} else if (!strchr(ref, ':')) {
+			if (!remote) {
+				/* lazily grab remote and local_refs */
+				remote = remote_get(repo);
+				local_refs = get_local_heads();
 			}
-			strcat(tag, refs[i]);
-			ref = tag;
-		} else if (deleterefs && !strchr(ref, ':')) {
-			char *delref;
-			int len = strlen(ref)+1;
-			delref = xmalloc(len+1);
-			strcpy(delref, ":");
-			strcat(delref, ref);
-			ref = delref;
-		} else if (deleterefs)
-			die(_("--delete only accepts plain target ref names"));
+			ref = map_refspec(ref, remote, local_refs);
+		}
 		add_refspec(ref);
 	}
 }
@@ -501,7 +541,7 @@ int cmd_push(int argc, const char **argv, const char *prefix)
 
 	if (argc > 0) {
 		repo = argv[0];
-		set_refspecs(argv + 1, argc - 1);
+		set_refspecs(argv + 1, argc - 1, repo);
 	}
 
 	rc = do_push(repo, flags);