Merge remote branch 'ko/master' into jc/read-tree-cache-tree-fix

* ko/master: (2325 commits)
  Git 1.7.2-rc2
  backmerge a few more fixes to 1.7.1.X series
  fix git branch -m in presence of cross devices
  t/t0006: specify timezone as EST5 not EST to comply with POSIX
  add missing && to submodule-merge testcase
  t/README: document more test helpers
  test-date: fix sscanf type conversion
  xdiff: optimise for no whitespace difference when ignoring whitespace.
  gitweb: Move evaluate_gitweb_config out of run_request
  parse_date: fix signedness in timezone calculation
  t0006: test timezone parsing
  rerere.txt: Document forget subcommand
  t/README: proposed rewording...
  t/README: Document the do's and don'ts of tests
  t/README: Add a section about skipping tests
  t/README: Document test_expect_code
  t/README: Document test_external*
  t/README: Document the prereq functions, and 3-arg test_*
  t/README: Typo: paralell -> parallel
  t/README: The trash is in 't/trash directory.$name'
  ...

Conflicts:
	builtin-read-tree.c

1 files changed, 34 insertions, 13 deletions

diff --git a/branch.c b/branch.c
index 05ef3f5c9c..2ab42aaf4d 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);
 		}
@@ -108,6 +118,7 @@ static int setup_tracking(const char *new_ref, const char *orig_ref,
 		switch (track) {
 		case BRANCH_TRACK_ALWAYS:
 		case BRANCH_TRACK_EXPLICIT:
+		case BRANCH_TRACK_OVERRIDE:
 			break;
 		default:
 			return 1;
@@ -128,18 +139,25 @@ void create_branch(const char *head,
 		   const char *name, const char *start_name,
 		   int force, int reflog, enum branch_track track)
 {
-	struct ref_lock *lock;
+	struct ref_lock *lock = NULL;
 	struct commit *commit;
 	unsigned char sha1[20];
 	char *real_ref, msg[PATH_MAX + 20];
 	struct strbuf ref = STRBUF_INIT;
 	int forcing = 0;
+	int dont_change_ref = 0;
+	int explicit_tracking = 0;
+
+	if (track == BRANCH_TRACK_EXPLICIT || track == BRANCH_TRACK_OVERRIDE)
+		explicit_tracking = 1;
 
 	if (strbuf_check_branch_ref(&ref, name))
 		die("'%s' is not a valid branch name.", name);
 
 	if (resolve_ref(ref.buf, sha1, 1, NULL)) {
-		if (!force)
+		if (!force && track == BRANCH_TRACK_OVERRIDE)
+			dont_change_ref = 1;
+		else if (!force)
 			die("A branch named '%s' already exists.", name);
 		else if (!is_bare_repository() && !strcmp(head, name))
 			die("Cannot force update the current branch.");
@@ -153,12 +171,12 @@ void create_branch(const char *head,
 	switch (dwim_ref(start_name, strlen(start_name), sha1, &real_ref)) {
 	case 0:
 		/* Not branching from any existing branch */
-		if (track == BRANCH_TRACK_EXPLICIT)
+		if (explicit_tracking)
 			die("Cannot setup tracking information; starting point is not a branch.");
 		break;
 	case 1:
 		/* Unique completion -- good, only if it is a real ref */
-		if (track == BRANCH_TRACK_EXPLICIT && !strcmp(real_ref, "HEAD"))
+		if (explicit_tracking && !strcmp(real_ref, "HEAD"))
 			die("Cannot setup tracking information; starting point is not a branch.");
 		break;
 	default:
@@ -170,25 +188,28 @@ void create_branch(const char *head,
 		die("Not a valid branch point: '%s'.", start_name);
 	hashcpy(sha1, commit->object.sha1);
 
-	lock = lock_any_ref_for_update(ref.buf, NULL, 0);
-	if (!lock)
-		die_errno("Failed to lock ref for update");
+	if (!dont_change_ref) {
+		lock = lock_any_ref_for_update(ref.buf, NULL, 0);
+		if (!lock)
+			die_errno("Failed to lock ref for update");
+	}
 
 	if (reflog)
 		log_all_ref_updates = 1;
 
 	if (forcing)
-		snprintf(msg, sizeof msg, "branch: Reset from %s",
+		snprintf(msg, sizeof msg, "branch: Reset to %s",
 			 start_name);
-	else
+	else if (!dont_change_ref)
 		snprintf(msg, sizeof msg, "branch: Created from %s",
 			 start_name);
 
 	if (real_ref && track)
 		setup_tracking(name, real_ref, track);
 
-	if (write_ref_sha1(lock, sha1, msg) < 0)
-		die_errno("Failed to write ref");
+	if (!dont_change_ref)
+		if (write_ref_sha1(lock, sha1, msg) < 0)
+			die_errno("Failed to write ref");
 
 	strbuf_release(&ref);
 	free(real_ref);