Merge branch 'fg/push-default'

* fg/push-default:
  builtin-push.c: Fix typo: "anythig" -> "anything"
  Display warning for default git push with no push.default config
  New config push.default to decide default behavior for push

Conflicts:
	Documentation/config.txt

6 files changed, 134 insertions, 5 deletions

diff --git a/Documentation/RelNotes-1.6.3.txt b/Documentation/RelNotes-1.6.3.txt
index 5860b515f5..0d8260a842 100644
--- a/Documentation/RelNotes-1.6.3.txt
+++ b/Documentation/RelNotes-1.6.3.txt
@@ -22,6 +22,13 @@ branch pointed at by its HEAD, gets a large warning.  You can choose what
 should happen upon such a push by setting the configuration variable
 receive.denyDeleteCurrent in the receiving repository.
 
+In a future release, the default of "git push" without further
+arguments might be changed. Currently, it will push all matching
+refspecs to the current remote.  A configuration variable push.default
+has been introduced to select the default behaviour.  To ease the
+transition, a big warning is issued if this is not configured and a
+git push without arguments is attempted.
+
 
 Updates since v1.6.2
 --------------------
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 12540b605f..750675530c 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -1194,6 +1194,24 @@ pull.octopus::
 pull.twohead::
 	The default merge strategy to use when pulling a single branch.
 
+push.default::
+	Defines the action git push should take if no refspec is given
+	on the command line, no refspec is configured in the remote, and
+	no refspec is implied by any of the options given on the command
+	line.
++
+The term `current remote` means the remote configured for the current
+branch, or `origin` if no remote is configured. `origin` is also used
+if you are not on any branch. Possible values are:
++
+* `nothing` do not push anything.
+* `matching` push all matching branches to the current remote.
+  All branches having the same name in both ends are considered to be
+  matching. This is the current default value.
+* `tracking` push the current branch to the branch it is tracking.
+* `current` push the current branch to a branch of the same name on the
+  current remote.
+
 rebase.stat::
 	Whether to show a diffstat of what changed upstream since the last
 	rebase. False by default.
diff --git a/builtin-push.c b/builtin-push.c
index ca36fb1e58..2eabcd3bdf 100644
--- a/builtin-push.c
+++ b/builtin-push.c
@@ -48,6 +48,71 @@ static void set_refspecs(const char **refs, int nr)
 	}
 }
 
+static void setup_push_tracking(void)
+{
+	struct strbuf refspec = STRBUF_INIT;
+	struct branch *branch = branch_get(NULL);
+	if (!branch)
+		die("You are not currently on a branch.");
+	if (!branch->merge_nr)
+		die("The current branch %s is not tracking anything.",
+		    branch->name);
+	if (branch->merge_nr != 1)
+		die("The current branch %s is tracking multiple branches, "
+		    "refusing to push.", branch->name);
+	strbuf_addf(&refspec, "%s:%s", branch->name, branch->merge[0]->src);
+	add_refspec(refspec.buf);
+}
+
+static const char *warn_unconfigured_push_msg[] = {
+	"You did not specify any refspecs to push, and the current remote",
+	"has not configured any push refspecs. The default action in this",
+	"case is to push all matching refspecs, that is, all branches",
+	"that exist both locally and remotely will be updated.  This may",
+	"not necessarily be what you want to happen.",
+	"",
+	"You can specify what action you want to take in this case, and",
+	"avoid seeing this message again, by configuring 'push.default' to:",
+	"  'nothing'  : Do not push anything",
+	"  'matching' : Push all matching branches (default)",
+	"  'tracking' : Push the current branch to whatever it is tracking",
+	"  'current'  : Push the current branch"
+};
+
+static void warn_unconfigured_push(void)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(warn_unconfigured_push_msg); i++)
+		warning("%s", warn_unconfigured_push_msg[i]);
+}
+
+static void setup_default_push_refspecs(void)
+{
+	git_config(git_default_config, NULL);
+	switch (push_default) {
+	case PUSH_DEFAULT_UNSPECIFIED:
+		warn_unconfigured_push();
+		/* fallthrough */
+
+	case PUSH_DEFAULT_MATCHING:
+		add_refspec(":");
+		break;
+
+	case PUSH_DEFAULT_TRACKING:
+		setup_push_tracking();
+		break;
+
+	case PUSH_DEFAULT_CURRENT:
+		add_refspec("HEAD");
+		break;
+
+	case PUSH_DEFAULT_NOTHING:
+		die("You didn't specify any refspecs to push, and "
+		    "push.default is \"nothing\".");
+		break;
+	}
+}
+
 static int do_push(const char *repo, int flags)
 {
 	int i, errs;
@@ -79,11 +144,12 @@ static int do_push(const char *repo, int flags)
 		return error("--all and --mirror are incompatible");
 	}
 
-	if (!refspec
-		&& !(flags & TRANSPORT_PUSH_ALL)
-		&& remote->push_refspec_nr) {
-		refspec = remote->push_refspec;
-		refspec_nr = remote->push_refspec_nr;
+	if (!refspec && !(flags & TRANSPORT_PUSH_ALL)) {
+		if (remote->push_refspec_nr) {
+			refspec = remote->push_refspec;
+			refspec_nr = remote->push_refspec_nr;
+		} else if (!(flags & TRANSPORT_PUSH_MIRROR))
+			setup_default_push_refspecs();
 	}
 	errs = 0;
 	for (i = 0; i < remote->url_nr; i++) {
diff --git a/cache.h b/cache.h
index 39789ee94a..f48e80bc05 100644
--- a/cache.h
+++ b/cache.h
@@ -542,8 +542,17 @@ enum rebase_setup_type {
 	AUTOREBASE_ALWAYS,
 };
 
+enum push_default_type {
+	PUSH_DEFAULT_UNSPECIFIED = -1,
+	PUSH_DEFAULT_NOTHING = 0,
+	PUSH_DEFAULT_MATCHING,
+	PUSH_DEFAULT_TRACKING,
+	PUSH_DEFAULT_CURRENT,
+};
+
 extern enum branch_track git_branch_track;
 extern enum rebase_setup_type autorebase;
+extern enum push_default_type push_default;
 
 #define GIT_REPO_VERSION 0
 extern int repository_format_version;
diff --git a/config.c b/config.c
index 50efd639c4..b76fe4c6dc 100644
--- a/config.c
+++ b/config.c
@@ -565,6 +565,31 @@ static int git_default_branch_config(const char *var, const char *value)
 	return 0;
 }
 
+static int git_default_push_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "push.default")) {
+		if (!value)
+			return config_error_nonbool(var);
+		else if (!strcmp(value, "nothing"))
+			push_default = PUSH_DEFAULT_NOTHING;
+		else if (!strcmp(value, "matching"))
+			push_default = PUSH_DEFAULT_MATCHING;
+		else if (!strcmp(value, "tracking"))
+			push_default = PUSH_DEFAULT_TRACKING;
+		else if (!strcmp(value, "current"))
+			push_default = PUSH_DEFAULT_CURRENT;
+		else {
+			error("Malformed value for %s: %s", var, value);
+			return error("Must be one of nothing, matching, "
+				     "tracking or current.");
+		}
+		return 0;
+	}
+
+	/* Add other config variables here and to Documentation/config.txt. */
+	return 0;
+}
+
 static int git_default_mailmap_config(const char *var, const char *value)
 {
 	if (!strcmp(var, "mailmap.file"))
@@ -588,6 +613,9 @@ int git_default_config(const char *var, const char *value, void *dummy)
 	if (!prefixcmp(var, "branch."))
 		return git_default_branch_config(var, value);
 
+	if (!prefixcmp(var, "push."))
+		return git_default_push_config(var, value);
+
 	if (!prefixcmp(var, "mailmap."))
 		return git_default_mailmap_config(var, value);
 
diff --git a/environment.c b/environment.c
index e278bce0ea..4696885b22 100644
--- a/environment.c
+++ b/environment.c
@@ -42,6 +42,7 @@ enum safe_crlf safe_crlf = SAFE_CRLF_WARN;
 unsigned whitespace_rule_cfg = WS_DEFAULT_RULE;
 enum branch_track git_branch_track = BRANCH_TRACK_REMOTE;
 enum rebase_setup_type autorebase = AUTOREBASE_NEVER;
+enum push_default_type push_default = PUSH_DEFAULT_UNSPECIFIED;
 
 /* Parallel index stat data preload? */
 int core_preload_index = 0;