From 85e2233f982f760d0e731b1258da2580834d8027 Mon Sep 17 00:00:00 2001
From: Matthieu Moy <Matthieu.Moy@imag.fr>
Date: Mon, 18 Jan 2010 22:44:12 +0200
Subject: branch: warn and refuse to set a branch as a tracking branch of
 itself.

Previous patch allows commands like "git branch --set-upstream foo foo",
which doesn't make much sense. Warn the user and don't change the
configuration in this case. Don't die to let the caller finish its job in
such case.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Ilari Liusvaara <ilari.liusvaara@elisanet.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/branch.c b/branch.c
index 40d3c45..9e1f63e 100644
--- a/branch.c
+++ b/branch.c
@@ -49,9 +49,19 @@ static int should_setup_rebase(const char *origin)
 
 void install_branch_config(int flag, const char *local, const char *origin, const char *remote)
 {
+	const char *shortname = remote + 11;
+	int remote_is_branch = !prefixcmp(remote, "refs/heads/");
 	struct strbuf key = STRBUF_INIT;
 	int rebasing = should_setup_rebase(origin);
 
+	if (remote_is_branch
+	    && !strcmp(local, shortname)
+	    && !origin) {
+		warning("Not setting branch %s as its own upstream.",
+			local);
+		return;
+	}
+
 	strbuf_addf(&key, "branch.%s.remote", local);
 	git_config_set(key.buf, origin ? origin : ".");
 
@@ -71,8 +81,8 @@ void install_branch_config(int flag, const char *local, const char *origin, cons
 		strbuf_addstr(&key, origin ? "remote" : "local");
 
 		/* Are we tracking a proper "branch"? */
-		if (!prefixcmp(remote, "refs/heads/")) {
-			strbuf_addf(&key, " branch %s", remote + 11);
+		if (remote_is_branch) {
+			strbuf_addf(&key, " branch %s", shortname);
 			if (origin)
 				strbuf_addf(&key, " from %s", origin);
 		}
-- 
cgit v0.10.2-6-g49f6