Merge branch 'jc/triangle-push-fixup'

Earlier remote.pushdefault (and per-branch branch.*.pushremote)
were introduced as an additional mechanism to choose what
repository to push into when "git push" did not say it from the
command line, to help people who push to a repository that is
different from where they fetch from.  This attempts to finish that
topic by teaching the default mechanism to choose branch in the
remote repository to be updated by such a push.

The 'current', 'matching' and 'nothing' modes (specified by the
push.default configuration variable) extend to such a "triangular"
workflow naturally, but 'upstream' and 'simple' have to be updated.

. 'upstream' is about pushing back to update the branch in the
  remote repository that the current branch fetches from and
  integrates with, it errors out in a triangular workflow.

. 'simple' is meant to help new people by avoiding mistakes, and
  will be the safe default in Git 2.0.

  In a non-triangular workflow, it will continue to act as a cross
  between 'upstream' and 'current' in that it pushes to the current
  branch's @{upstream} only when it is set to the same name as the
  current branch (e.g. your 'master' forks from the 'master' from
  the central repository).

  In a triangular workflow, this series tentatively defines it as
  the same as 'current', but we may have to tighten it to avoid
  surprises in some way.

* jc/triangle-push-fixup:
  t/t5528-push-default: test pushdefault workflows
  t/t5528-push-default: generalize test_push_*
  push: change `simple` to accommodate triangular workflows
  config doc: rewrite push.default section
  t/t5528-push-default: remove redundant test_config lines

1 files changed, 31 insertions, 12 deletions

diff --git a/builtin/push.c b/builtin/push.c
index 2d84d10720..a2580a94f5 100644
--- a/builtin/push.c
+++ b/builtin/push.c
@@ -120,10 +120,11 @@ static const char message_detached_head_die[] =
 	   "\n"
 	   "    git push %s HEAD:<name-of-remote-branch>\n");
 
-static void setup_push_upstream(struct remote *remote, int simple)
+static void setup_push_upstream(struct remote *remote, struct branch *branch,
+				int triangular)
 {
 	struct strbuf refspec = STRBUF_INIT;
-	struct branch *branch = branch_get(NULL);
+
 	if (!branch)
 		die(_(message_detached_head_die), remote->name);
 	if (!branch->merge_nr || !branch->merge || !branch->remote_name)
@@ -137,18 +138,29 @@ static void setup_push_upstream(struct remote *remote, int simple)
 	if (branch->merge_nr != 1)
 		die(_("The current branch %s has multiple upstream branches, "
 		    "refusing to push."), branch->name);
-	if (strcmp(branch->remote_name, remote->name))
+	if (triangular)
 		die(_("You are pushing to remote '%s', which is not the upstream of\n"
 		      "your current branch '%s', without telling me what to push\n"
 		      "to update which remote branch."),
 		    remote->name, branch->name);
-	if (simple && strcmp(branch->refname, branch->merge[0]->src))
-		die_push_simple(branch, remote);
+
+	if (push_default == PUSH_DEFAULT_SIMPLE) {
+		/* Additional safety */
+		if (strcmp(branch->refname, branch->merge[0]->src))
+			die_push_simple(branch, remote);
+	}
 
 	strbuf_addf(&refspec, "%s:%s", branch->name, branch->merge[0]->src);
 	add_refspec(refspec.buf);
 }
 
+static void setup_push_current(struct remote *remote, struct branch *branch)
+{
+	if (!branch)
+		die(_(message_detached_head_die), remote->name);
+	add_refspec(branch->name);
+}
+
 static char warn_unspecified_push_default_msg[] =
 N_("push.default is unset; its implicit value is changing in\n"
    "Git 2.0 from 'matching' to 'simple'. To squelch this message\n"
@@ -173,9 +185,16 @@ static void warn_unspecified_push_default_configuration(void)
 	warning("%s\n", _(warn_unspecified_push_default_msg));
 }
 
+static int is_workflow_triangular(struct remote *remote)
+{
+	struct remote *fetch_remote = remote_get(NULL);
+	return (fetch_remote && fetch_remote != remote);
+}
+
 static void setup_default_push_refspecs(struct remote *remote)
 {
-	struct branch *branch;
+	struct branch *branch = branch_get(NULL);
+	int triangular = is_workflow_triangular(remote);
 
 	switch (push_default) {
 	default:
@@ -188,18 +207,18 @@ static void setup_default_push_refspecs(struct remote *remote)
 		break;
 
 	case PUSH_DEFAULT_SIMPLE:
-		setup_push_upstream(remote, 1);
+		if (triangular)
+			setup_push_current(remote, branch);
+		else
+			setup_push_upstream(remote, branch, triangular);
 		break;
 
 	case PUSH_DEFAULT_UPSTREAM:
-		setup_push_upstream(remote, 0);
+		setup_push_upstream(remote, branch, triangular);
 		break;
 
 	case PUSH_DEFAULT_CURRENT:
-		branch = branch_get(NULL);
-		if (!branch)
-			die(_(message_detached_head_die), remote->name);
-		add_refspec(branch->name);
+		setup_push_current(remote, branch);
 		break;
 
 	case PUSH_DEFAULT_NOTHING: