[PATCH v4] remote rename/remove: gently handle remote.pushDefault config

[Bert Wesarg <bert.wesarg@googlemail.com>]

When renaming a remote with

    git remote rename X Y
    git remote remove X

Git already renames or removes any branch.<name>.remote and
branch.<name>.pushRemote configurations if their value is X.

However remote.pushDefault needs a more gentle approach, as this may be
set in a non-repo configuration file. In such a case only a warning is
printed, such as:

warning: The global configuration remote.pushDefault in:
	$HOME/.gitconfig:35
now names the non-existent remote origin

It is changed to remote.pushDefault = Y or removed when set in a repo
configuration though.

Signed-off-by: Bert Wesarg <bert.wesarg@googlemail.com>
---

Matthew, you are in Cc because of your current work 'config: allow user to
know scope of config options'. I think I'm correct to assuming an ordering
of the enum config_scope.

Changes since v3:
 * do not use `test_config_global` in a subshell

Changes since v1:
 * handle also 'git remote remove'

Cc: Junio C Hamano <gitster@pobox.com>
Cc: Johannes Schindelin <johannes.schindelin@gmx.de>
Cc: Matthew Rogers <mattr94@gmail.com>
---
 builtin/remote.c  | 54 +++++++++++++++++++++++++++++++++
 t/t5505-remote.sh | 76 +++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 128 insertions(+), 2 deletions(-)

diff --git a/builtin/remote.c b/builtin/remote.c
index a2379a14bf..5af06b74a7 100644
--- a/builtin/remote.c
+++ b/builtin/remote.c
@@ -615,6 +615,55 @@ static int migrate_file(struct remote *remote)
 	return 0;
 }
 
+struct push_default_info
+{
+	const char *old_name;
+	enum config_scope scope;
+	struct strbuf origin;
+	int linenr;
+};
+
+static int config_read_push_default(const char *key, const char *value,
+	void *cb)
+{
+	struct push_default_info* info = cb;
+	if (strcmp(key, "remote.pushdefault") || strcmp(value, info->old_name))
+		return 0;
+
+	info->scope = current_config_scope();
+	strbuf_reset(&info->origin);
+	strbuf_addstr(&info->origin, current_config_name());
+	info->linenr = current_config_line();
+
+	return 0;
+}
+
+static void handle_push_default(const char* old_name, const char* new_name)
+{
+	struct push_default_info push_default = {
+		old_name, CONFIG_SCOPE_UNKNOWN, STRBUF_INIT, -1 };
+	git_config(config_read_push_default, &push_default);
+	if (push_default.scope >= CONFIG_SCOPE_COMMAND)
+		; /* pass */
+	else if (push_default.scope >= CONFIG_SCOPE_LOCAL) {
+		int result = git_config_set_gently("remote.pushDefault",
+						   new_name);
+		if (new_name && result && result != CONFIG_NOTHING_SET)
+			die(_("could not set '%s'"), "remote.pushDefault");
+		else if (!new_name && result && result != CONFIG_NOTHING_SET)
+			die(_("could not unset '%s'"), "remote.pushDefault");
+	} else if (push_default.scope >= CONFIG_SCOPE_SYSTEM) {
+		/* warn */
+		warning(_("The %s configuration remote.pushDefault in:\n"
+			  "\t%s:%d\n"
+			  "now names the non-existent remote '%s'"),
+			config_scope_name(push_default.scope),
+			push_default.origin.buf, push_default.linenr,
+			old_name);
+	}
+}
+
+
 static int mv(int argc, const char **argv)
 {
 	struct option options[] = {
@@ -750,6 +799,9 @@ static int mv(int argc, const char **argv)
 			die(_("creating '%s' failed"), buf.buf);
 	}
 	string_list_clear(&remote_branches, 1);
+
+	handle_push_default(rename.old_name, rename.new_name);
+
 	return 0;
 }
 
@@ -835,6 +887,8 @@ static int rm(int argc, const char **argv)
 		strbuf_addf(&buf, "remote.%s", remote->name);
 		if (git_config_rename_section(buf.buf, NULL) < 1)
 			return error(_("Could not remove config section '%s'"), buf.buf);
+
+		handle_push_default(remote->name, NULL);
 	}
 
 	return result;
diff --git a/t/t5505-remote.sh b/t/t5505-remote.sh
index 082042b05a..dda81b7d07 100755
--- a/t/t5505-remote.sh
+++ b/t/t5505-remote.sh
@@ -734,6 +734,7 @@ test_expect_success 'reject adding remote with an invalid name' '
 # the last two ones check if the config is updated.
 
 test_expect_success 'rename a remote' '
+	test_config_global remote.pushDefault origin &&
 	git clone one four &&
 	(
 		cd four &&
@@ -744,7 +745,42 @@ test_expect_success 'rename a remote' '
 		test "$(git rev-parse upstream/master)" = "$(git rev-parse master)" &&
 		test "$(git config remote.upstream.fetch)" = "+refs/heads/*:refs/remotes/upstream/*" &&
 		test "$(git config branch.master.remote)" = "upstream" &&
-		test "$(git config branch.master.pushRemote)" = "upstream"
+		test "$(git config branch.master.pushRemote)" = "upstream" &&
+		test "$(git config --global remote.pushDefault)" = "origin"
+	)
+'
+
+test_expect_success 'rename a remote renames repo remote.pushDefault' '
+	git clone one four.1 &&
+	(
+		cd four.1 &&
+		git config remote.pushDefault origin &&
+		git remote rename origin upstream &&
+		test "$(git config --local remote.pushDefault)" = "upstream"
+	)
+'
+
+test_expect_success 'rename a remote renames repo remote.pushDefault but ignores global' '
+	test_config_global remote.pushDefault other &&
+	git clone one four.2 &&
+	(
+		cd four.2 &&
+		git config remote.pushDefault origin &&
+		git remote rename origin upstream &&
+		test "$(git config --global remote.pushDefault)" = "other" &&
+		test "$(git config --local remote.pushDefault)" = "upstream"
+	)
+'
+
+test_expect_success 'rename a remote renames repo remote.pushDefault but keeps global' '
+	test_config_global remote.pushDefault origin &&
+	git clone one four.3 &&
+	(
+		cd four.3 &&
+		git config remote.pushDefault origin &&
+		git remote rename origin upstream &&
+		test "$(git config --global remote.pushDefault)" = "origin" &&
+		test "$(git config --local remote.pushDefault)" = "upstream"
 	)
 '
 
@@ -787,6 +823,7 @@ test_expect_success 'rename succeeds with existing remote.<target>.prune' '
 '
 
 test_expect_success 'remove a remote' '
+	test_config_global remote.pushDefault origin &&
 	git clone one four.five &&
 	(
 		cd four.five &&
@@ -794,7 +831,42 @@ test_expect_success 'remove a remote' '
 		git remote remove origin &&
 		test -z "$(git for-each-ref refs/remotes/origin)" &&
 		test_must_fail git config branch.master.remote &&
-		test_must_fail git config branch.master.pushRemote
+		test_must_fail git config branch.master.pushRemote &&
+		test "$(git config --global remote.pushDefault)" = "origin"
+	)
+'
+
+test_expect_success 'remove a remote removes repo remote.pushDefault' '
+	git clone one four.five.1 &&
+	(
+		cd four.five.1 &&
+		git config remote.pushDefault origin &&
+		git remote remove origin &&
+		test_must_fail git config --local remote.pushDefault
+	)
+'
+
+test_expect_success 'remove a remote removes repo remote.pushDefault but ignores global' '
+	test_config_global remote.pushDefault other &&
+	git clone one four.five.2 &&
+	(
+		cd four.five.2 &&
+		git config remote.pushDefault origin &&
+		git remote remove origin &&
+		test "$(git config --global remote.pushDefault)" = "other" &&
+		test_must_fail git config --local remote.pushDefault
+	)
+'
+
+test_expect_success 'remove a remote removes repo remote.pushDefault but keeps global' '
+	test_config_global remote.pushDefault origin &&
+	git clone one four.five.3 &&
+	(
+		cd four.five.3 &&
+		git config remote.pushDefault origin &&
+		git remote remove origin &&
+		test "$(git config --global remote.pushDefault)" = "origin" &&
+		test_must_fail git config --local remote.pushDefault
 	)
 '
 
-- 
2.25.0.30.g00ce2e43d4