builtin/branch: stop supporting the "--set-upstream" option

The '--set-upstream' option of branch was deprecated in b347d06b
("branch: deprecate --set-upstream and show help if we detect
possible mistaken use", 2012-08-30) and has been planned for removal
ever since.

In order to prevent "--set-upstream" on a command line from being taken as
an abbreviated form of "--set-upstream-to", explicitly catch "--set-upstream"
option and die, instead of just removing it from the list of options.

Before this change, an attempt to use "--set-upstream" resulted in:

    $ git branch
    * master

    $ git branch --set-upstream origin/master
    The --set-upstream flag is deprecated and will be removed. Consider using --track or --set-upstream-to
    Branch origin/master set up to track local branch master.

    $ echo $?
    0

    $ git branch
    * master
      origin/master

With this change, the behaviour becomes like this:

    $ git branch
    * master

    $ git branch --set-upstream origin/master
    fatal: the '--set-upstream' option is no longer supported. Please use '--track' or '--set-upstream-to' instead.

    $ echo $?
    128

    $ git branch
    * master

Signed-off-by: Kaartic Sivaraam <kaarticsivaraam91196@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-branch.txt

@@ -195,10 +195,8 @@ start-point is either a local or remote-tracking branch.
 	branch.autoSetupMerge configuration variable is true.
 --set-upstream::
-	If specified branch does not exist yet or if `--force` has been
-	given, acts exactly like `--track`. Otherwise sets up configuration
-	like `--track` would when creating the branch, except that where
-	branch points to is not changed.
+	As this option had confusing syntax, it is no longer supported.
+	Please use `--track` or `--set-upstream-to` instead.
 -u <upstream>::
 --set-upstream-to=<upstream>::

builtin/branch.c

@@ -561,8 +561,8 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		OPT__QUIET(&quiet, N_("suppress informational messages")),
 		OPT_SET_INT('t', "track",  &track, N_("set up tracking mode (see git-pull(1))"),
 			BRANCH_TRACK_EXPLICIT),
-		OPT_SET_INT( 0, "set-upstream",  &track, N_("change upstream info"),
-			BRANCH_TRACK_OVERRIDE),
+		{ OPTION_SET_INT, 0, "set-upstream", &track, NULL, N_("do not use"),
+			PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, BRANCH_TRACK_OVERRIDE },
 		OPT_STRING('u', "set-upstream-to", &new_upstream, N_("upstream"), N_("change the upstream info")),
 		OPT_BOOL(0, "unset-upstream", &unset_upstream, N_("Unset the upstream info")),
 		OPT__COLOR(&branch_use_color, N_("use colored output")),
@@ -759,8 +759,6 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		strbuf_release(&buf);
 	} else if (argc > 0 && argc <= 2) {
 		struct branch *branch = branch_get(argv[0]);
-		int branch_existed = 0, remote_tracking = 0;
-		struct strbuf buf = STRBUF_INIT;
 		if (!strcmp(argv[0], "HEAD"))
 			die(_("it does not make sense to create 'HEAD' manually"));
@@ -772,28 +770,11 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 			die(_("-a and -r options to 'git branch' do not make sense with a branch name"));
 		if (track == BRANCH_TRACK_OVERRIDE)
-			fprintf(stderr, _("The --set-upstream flag is deprecated and will be removed. Consider using --track or --set-upstream-to\n"));
-
-		strbuf_addf(&buf, "refs/remotes/%s", branch->name);
-		remote_tracking = ref_exists(buf.buf);
-		strbuf_release(&buf);
-		branch_existed = ref_exists(branch->refname);
+			die(_("the '--set-upstream' option is no longer supported. Please use '--track' or '--set-upstream-to' instead."));
 		create_branch(argv[0], (argc == 2) ? argv[1] : head,
 			      force, reflog, 0, quiet, track);
-		/*
-		 * We only show the instructions if the user gave us
-		 * one branch which doesn't exist locally, but is the
-		 * name of a remote-tracking branch.
-		 */
-		if (argc == 1 && track == BRANCH_TRACK_OVERRIDE &&
-		    !branch_existed && remote_tracking) {
-			fprintf(stderr, _("\nIf you wanted to make '%s' track '%s', do this:\n\n"), head, branch->name);
-			fprintf(stderr, "    git branch -d %s\n", branch->name);
-			fprintf(stderr, "    git branch --set-upstream-to %s\n", branch->name);
-		}
-
 	} else
 		usage_with_options(builtin_branch_usage, options);

t/t3200-branch.sh

@@ -605,38 +605,8 @@ test_expect_success 'test --unset-upstream on a particular branch' '
 	test_must_fail git config branch.my14.merge
 '
-test_expect_success '--set-upstream shows message when creating a new branch that exists as remote-tracking' '
-	git update-ref refs/remotes/origin/master HEAD &&
-	git branch --set-upstream origin/master 2>actual &&
-	test_when_finished git update-ref -d refs/remotes/origin/master &&
-	test_when_finished git branch -d origin/master &&
-	cat >expected <<EOF &&
-The --set-upstream flag is deprecated and will be removed. Consider using --track or --set-upstream-to
-
-If you wanted to make '"'master'"' track '"'origin/master'"', do this:
-
-    git branch -d origin/master
-    git branch --set-upstream-to origin/master
-EOF
-	test_i18ncmp expected actual
-'
-
-test_expect_success '--set-upstream with two args only shows the deprecation message' '
-	git branch --set-upstream master my13 2>actual &&
-	test_when_finished git branch --unset-upstream master &&
-	cat >expected <<EOF &&
-The --set-upstream flag is deprecated and will be removed. Consider using --track or --set-upstream-to
-EOF
-	test_i18ncmp expected actual
-'
-
-test_expect_success '--set-upstream with one arg only shows the deprecation message if the branch existed' '
-	git branch --set-upstream my13 2>actual &&
-	test_when_finished git branch --unset-upstream my13 &&
-	cat >expected <<EOF &&
-The --set-upstream flag is deprecated and will be removed. Consider using --track or --set-upstream-to
-EOF
-	test_i18ncmp expected actual
+test_expect_success '--set-upstream fails' '
+    test_must_fail git branch --set-upstream origin/master
 '
 test_expect_success '--set-upstream-to notices an error to set branch as own upstream' '
@@ -961,19 +931,6 @@ test_expect_success 'attempt to delete a branch merged to its base' '
 	test_must_fail git branch -d my10
 '
-test_expect_success 'use set-upstream on the current branch' '
-	git checkout master &&
-	git --bare init myupstream.git &&
-	git push myupstream.git master:refs/heads/frotz &&
-	git remote add origin myupstream.git &&
-	git fetch &&
-	git branch --set-upstream master origin/frotz &&
-
-	test "z$(git config branch.master.remote)" = "zorigin" &&
-	test "z$(git config branch.master.merge)" = "zrefs/heads/frotz"
-
-'
-
 test_expect_success 'use --edit-description' '
 	write_script editor <<-\EOF &&
 		echo "New contents" >"$1"

t/t6040-tracking-info.sh

@@ -188,35 +188,29 @@ test_expect_success 'fail to track annotated tags' '
 	test_must_fail git checkout heavytrack
 '
-test_expect_success 'setup tracking with branch --set-upstream on existing branch' '
+test_expect_success '--set-upstream-to does not change branch' '
 	git branch from-master master &&
-	test_must_fail git config branch.from-master.merge > actual &&
-	git branch --set-upstream from-master master &&
-	git config branch.from-master.merge > actual &&
-	grep -q "^refs/heads/master$" actual
-'
-
-test_expect_success '--set-upstream does not change branch' '
+	git branch --set-upstream-to master from-master &&
 	git branch from-master2 master &&
 	test_must_fail git config branch.from-master2.merge > actual &&
 	git rev-list from-master2 &&
 	git update-ref refs/heads/from-master2 from-master2^ &&
 	git rev-parse from-master2 >expect2 &&
-	git branch --set-upstream from-master2 master &&
+	git branch --set-upstream-to master from-master2 &&
 	git config branch.from-master.merge > actual &&
 	git rev-parse from-master2 >actual2 &&
 	grep -q "^refs/heads/master$" actual &&
 	cmp expect2 actual2
 '
-test_expect_success '--set-upstream @{-1}' '
-	git checkout from-master &&
+test_expect_success '--set-upstream-to @{-1}' '
+	git checkout follower &&
 	git checkout from-master2 &&
 	git config branch.from-master2.merge > expect2 &&
-	git branch --set-upstream @{-1} follower &&
+	git branch --set-upstream-to @{-1} from-master &&
 	git config branch.from-master.merge > actual &&
 	git config branch.from-master2.merge > actual2 &&
-	git branch --set-upstream from-master follower &&
+	git branch --set-upstream-to follower from-master &&
 	git config branch.from-master.merge > expect &&
 	test_cmp expect2 actual2 &&
 	test_cmp expect actual