[PATCH v3] Add core.mode configuration

[Felipe Contreras <felipe.contreras@gmail.com>]

So that we can specify general modes of operation, specifically, add the
'next' mode, which makes Git pre v2.0 behave as Git v2.0.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>
---
 builtin/add.c      | 13 ++++++++----
 cache.h            |  6 ++++++
 config.c           | 13 ++++++++++++
 environment.c      |  1 +
 t/t2205-add-new.sh | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 89 insertions(+), 4 deletions(-)
 create mode 100755 t/t2205-add-new.sh

diff --git a/builtin/add.c b/builtin/add.c
index 8266a9c..95a396d 100644
--- a/builtin/add.c
+++ b/builtin/add.c
@@ -483,14 +483,16 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 	 */
 	memset(&update_data, 0, sizeof(update_data));
 	if (!take_worktree_changes && addremove_explicit < 0)
-		update_data.warn_add_would_remove = 1;
+		if (git_mode == MODE_CURRENT)
+			update_data.warn_add_would_remove = 1;
 
 	if (!take_worktree_changes && addremove_explicit < 0 && argc)
 		/*
 		 * Turn "git add pathspec..." to "git add -A pathspec..."
 		 * in Git 2.0 but not yet
 		 */
-		; /* addremove = 1; */
+		if (git_mode != MODE_CURRENT)
+			addremove = 1;
 
 	if (!show_only && ignore_missing)
 		die(_("Option --ignore-missing can only be used together with --dry-run"));
@@ -503,10 +505,13 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 		short_option_with_implicit_dot = "-u";
 	}
 	if (option_with_implicit_dot && !argc) {
-		static const char *here[2] = { ".", NULL };
+		static const char *here[2] = { ":/", NULL };
 		argc = 1;
 		argv = here;
-		implicit_dot = 1;
+		if (git_mode == MODE_CURRENT) {
+			here[0] = ".";
+			implicit_dot = 1;
+		}
 	}
 
 	add_new_files = !take_worktree_changes && !refresh_only;
diff --git a/cache.h b/cache.h
index 85b544f..f28240f 100644
--- a/cache.h
+++ b/cache.h
@@ -627,9 +627,15 @@ enum push_default_type {
 	PUSH_DEFAULT_UNSPECIFIED
 };
 
+enum git_mode {
+	MODE_CURRENT = 0,
+	MODE_NEXT
+};
+
 extern enum branch_track git_branch_track;
 extern enum rebase_setup_type autorebase;
 extern enum push_default_type push_default;
+extern enum git_mode git_mode;
 
 enum object_creation_mode {
 	OBJECT_CREATION_USES_HARDLINKS = 0,
diff --git a/config.c b/config.c
index e13a7b6..f0e0370 100644
--- a/config.c
+++ b/config.c
@@ -831,6 +831,19 @@ static int git_default_core_config(const char *var, const char *value)
 		return 0;
 	}
 
+	if (!strcmp(var, "core.mode")) {
+		if (!value)
+			return config_error_nonbool(var);
+		else if (!strcmp(value, "current"))
+			git_mode = MODE_CURRENT;
+		else if (!strcmp(value, "next")) {
+			git_mode = MODE_NEXT;
+			push_default = PUSH_DEFAULT_SIMPLE;
+		} else
+			die("wrong mode '%s'", value);
+		return 0;
+	}
+
 	/* Add other config variables here and to Documentation/config.txt. */
 	return 0;
 }
diff --git a/environment.c b/environment.c
index 5398c36..751e14d 100644
--- a/environment.c
+++ b/environment.c
@@ -62,6 +62,7 @@ int merge_log_config = -1;
 int precomposed_unicode = -1; /* see probe_utf8_pathname_composition() */
 struct startup_info *startup_info;
 unsigned long pack_size_limit_cfg;
+enum git_mode git_mode = MODE_CURRENT;
 
 /*
  * The character that begins a commented line in user-editable file
diff --git a/t/t2205-add-new.sh b/t/t2205-add-new.sh
new file mode 100755
index 0000000..763664b
--- /dev/null
+++ b/t/t2205-add-new.sh
@@ -0,0 +1,60 @@
+#!/bin/sh
+
+test_description='git add v2.0 behavior'
+
+. ./test-lib.sh
+
+test_expect_success setup '
+	mkdir dir1 &&
+	echo one > dir1/content &&
+	echo one > dir1/to-remove &&
+	git add . &&
+	git commit -m one
+'
+
+test_expect_success 'update in dir throws warning' '
+	test_when_finished "git reset --hard" &&
+	echo two > dir1/content &&
+	mkdir -p dir2 &&
+	(
+	cd dir2 &&
+	git add -u 2> err &&
+	cat err &&
+	grep "will change in Git 2.0" err
+	)
+'
+
+test_expect_success 'update in dir updates everything' '
+	test_when_finished "git reset --hard" &&
+	test_config core.mode next &&
+	echo two > dir1/content &&
+	mkdir -p dir2 &&
+	(
+	cd dir2 &&
+	git add -u 2> err &&
+	cat err &&
+	! grep "will change in Git 2.0" err
+	) &&
+	test "$(git ls-files -m)" = ""
+'
+
+test_expect_success 'default to ignore removal' '
+	test_when_finished "git reset --hard" &&
+	rm dir1/to-remove &&
+	git add dir1 2> err &&
+	cat err &&
+	grep "will change in Git 2.0" err &&
+	test "$(git ls-files -c)" != "dir1/content"
+'
+
+test_expect_success 'default adds removals' '
+	test_when_finished "git reset --hard" &&
+	test_config core.mode next &&
+	rm dir1/to-remove &&
+	git add dir1 2> err &&
+	cat err &&
+	! grep "will change in Git 2.0" err &&
+	test "$(git ls-files -c)" = "dir1/content"
+'
+
+test_done
-- 
1.8.4-fc