switch: no worktree status unless real branch switch happens

When we switch from one branch to another, it makes sense to show a
summary of local changes since there could be conflicts, or some files
left modified.... When switch is used solely for creating a new
branch (and "switch" to the same commit) or detaching, we don't really
need to show anything.

"git checkout" does it anyway for historical reasons. But we can start
with a clean slate with switch and don't have to.

This essentially reverts fa655d8411 (checkout: optimize "git checkout
-b <new_branch>" - 2018-08-16) and make it default for switch,
but also for -B and --detach. Users of big repos are encouraged to
move to switch.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/config/checkout.txt b/Documentation/config/checkout.txt
index d6872ffa83ea5a715e0cc3b0e6dde77efafb026b..6b646813abadc95a969d5c20f6c4350a284bf129 100644 (file)
--- a/Documentation/config/checkout.txt
+++ b/Documentation/config/checkout.txt
@@ -16,11 +16,3 @@ will checkout the '<something>' branch on another remote,
 and by linkgit:git-worktree[1] when 'git worktree add' refers to a
 remote branch. This setting might be used for other checkout-like
 commands or functionality in the future.
 and by linkgit:git-worktree[1] when 'git worktree add' refers to a
 remote branch. This setting might be used for other checkout-like
 commands or functionality in the future.

-
-checkout.optimizeNewBranch::
-       Optimizes the performance of "git checkout -b <new_branch>" when
-       using sparse-checkout.  When set to true, git will not update the
-       repo based on the current sparse-checkout settings.  This means it
-       will not update the skip-worktree bit in the index nor add/remove
-       files in the working directory to reflect the current sparse checkout
-       settings nor will it show the local changes.

diff --git a/builtin/checkout.c b/builtin/checkout.c
index ff9b96993d2bd137bd1e639a817ece4ebed068a0..f7967cdb7c9eca20e40ba5edc2224c79f10f766f 100644 (file)
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -26,8 +26,6 @@
 #include "unpack-trees.h"
 #include "xdiff-interface.h"
 
 #include "unpack-trees.h"
 #include "xdiff-interface.h"
 

-static int checkout_optimize_new_branch;
-

 static const char * const checkout_usage[] = {
        N_("git checkout [<options>] <branch>"),
        N_("git checkout [<options>] [<branch>] -- <file>..."),
 static const char * const checkout_usage[] = {
        N_("git checkout [<options>] <branch>"),
        N_("git checkout [<options>] [<branch>] -- <file>..."),


@@ -57,11 +55,7 @@ struct checkout_opts {
        int discard_changes;
        int accept_pathspec;
        int switch_branch_doing_nothing_is_ok;
        int discard_changes;
        int accept_pathspec;
        int switch_branch_doing_nothing_is_ok;

-
-       /*
-        * If new checkout options are added, skip_merge_working_tree
-        * should be updated accordingly.
-        */
+       int only_merge_on_switching_branches;

 
        const char *new_branch;
        const char *new_branch_force;
 
        const char *new_branch;
        const char *new_branch_force;


@@ -565,112 +559,6 @@ static void setup_branch_path(struct branch_info *branch)
        branch->path = strbuf_detach(&buf, NULL);
 }
 
        branch->path = strbuf_detach(&buf, NULL);
 }
 

-/*
- * Skip merging the trees, updating the index and working directory if and
- * only if we are creating a new branch via "git checkout -b <new_branch>."
- */
-static int skip_merge_working_tree(const struct checkout_opts *opts,
-       const struct branch_info *old_branch_info,
-       const struct branch_info *new_branch_info)
-{
-       /*
-        * Do the merge if sparse checkout is on and the user has not opted in
-        * to the optimized behavior
-        */
-       if (core_apply_sparse_checkout && !checkout_optimize_new_branch)
-               return 0;
-
-       /*
-        * We must do the merge if we are actually moving to a new commit.
-        */
-       if (!old_branch_info->commit || !new_branch_info->commit ||
-               !oideq(&old_branch_info->commit->object.oid,
-                      &new_branch_info->commit->object.oid))
-               return 0;
-
-       /*
-        * opts->patch_mode cannot be used with switching branches so is
-        * not tested here
-        */
-
-       /*
-        * opts->quiet only impacts output so doesn't require a merge
-        */
-
-       /*
-        * Honor the explicit request for a three-way merge or to throw away
-        * local changes
-        */
-       if (opts->merge || opts->force)
-               return 0;
-
-       /*
-        * --detach is documented as "updating the index and the files in the
-        * working tree" but this optimization skips those steps so fall through
-        * to the regular code path.
-        */
-       if (opts->force_detach)
-               return 0;
-
-       /*
-        * opts->writeout_stage cannot be used with switching branches so is
-        * not tested here
-        */
-
-       /*
-        * Honor the explicit ignore requests
-        */
-       if (!opts->overwrite_ignore || opts->ignore_skipworktree ||
-               opts->ignore_other_worktrees)
-               return 0;
-
-       /*
-        * opts->show_progress only impacts output so doesn't require a merge
-        */
-
-       /*
-        * opts->overlay_mode cannot be used with switching branches so is
-        * not tested here
-        */
-
-       /*
-        * If we aren't creating a new branch any changes or updates will
-        * happen in the existing branch.  Since that could only be updating
-        * the index and working directory, we don't want to skip those steps
-        * or we've defeated any purpose in running the command.
-        */
-       if (!opts->new_branch)
-               return 0;
-
-       /*
-        * new_branch_force is defined to "create/reset and checkout a branch"
-        * so needs to go through the merge to do the reset
-        */
-       if (opts->new_branch_force)
-               return 0;
-
-       /*
-        * A new orphaned branch requrires the index and the working tree to be
-        * adjusted to <start_point>
-        */
-       if (opts->new_orphan_branch)
-               return 0;
-
-       /*
-        * Remaining variables are not checkout options but used to track state
-        */
-
-        /*
-         * Do the merge if this is the initial checkout. We cannot use
-         * is_cache_unborn() here because the index hasn't been loaded yet
-         * so cache_nr and timestamp.sec are always zero.
-         */
-       if (!file_exists(get_index_file()))
-               return 0;
-
-       return 1;
-}
-

 static int merge_working_tree(const struct checkout_opts *opts,
                              struct branch_info *old_branch_info,
                              struct branch_info *new_branch_info,
 static int merge_working_tree(const struct checkout_opts *opts,
                              struct branch_info *old_branch_info,
                              struct branch_info *new_branch_info,


@@ -1028,6 +916,7 @@ static int switch_branches(const struct checkout_opts *opts,
        void *path_to_free;
        struct object_id rev;
        int flag, writeout_error = 0;
        void *path_to_free;
        struct object_id rev;
        int flag, writeout_error = 0;

+       int do_merge = 1;

 
        trace2_cmd_mode("branch");
 
 
        trace2_cmd_mode("branch");
 


@@ -1047,16 +936,12 @@ static int switch_branches(const struct checkout_opts *opts,
                if (!new_branch_info->commit)
                        die(_("You are on a branch yet to be born"));
                parse_commit_or_die(new_branch_info->commit);
                if (!new_branch_info->commit)
                        die(_("You are on a branch yet to be born"));
                parse_commit_or_die(new_branch_info->commit);

+
+               if (opts->only_merge_on_switching_branches)
+                       do_merge = 0;

        }
 
        }
 

-       /* optimize the "checkout -b <new_branch> path */
-       if (skip_merge_working_tree(opts, &old_branch_info, new_branch_info)) {
-               if (!checkout_optimize_new_branch && !opts->quiet) {
-                       if (read_cache_preload(NULL) < 0)
-                               return error(_("index file corrupt"));
-                       show_local_changes(&new_branch_info->commit->object, &opts->diff_options);
-               }
-       } else {
+       if (do_merge) {

                ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
                if (ret) {
                        free(path_to_free);
                ret = merge_working_tree(opts, &old_branch_info, new_branch_info, &writeout_error);
                if (ret) {
                        free(path_to_free);


@@ -1076,11 +961,6 @@ static int switch_branches(const struct checkout_opts *opts,
 
 static int git_checkout_config(const char *var, const char *value, void *cb)
 {
 
 static int git_checkout_config(const char *var, const char *value, void *cb)
 {

-       if (!strcmp(var, "checkout.optimizenewbranch")) {
-               checkout_optimize_new_branch = git_config_bool(var, value);
-               return 0;
-       }
-

        if (!strcmp(var, "diff.ignoresubmodules")) {
                struct checkout_opts *opts = cb;
                handle_ignore_submodules_arg(&opts->diff_options, value);
        if (!strcmp(var, "diff.ignoresubmodules")) {
                struct checkout_opts *opts = cb;
                handle_ignore_submodules_arg(&opts->diff_options, value);


@@ -1631,6 +1511,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
        memset(&opts, 0, sizeof(opts));
        opts.dwim_new_local_branch = 1;
        opts.switch_branch_doing_nothing_is_ok = 1;
        memset(&opts, 0, sizeof(opts));
        opts.dwim_new_local_branch = 1;
        opts.switch_branch_doing_nothing_is_ok = 1;

+       opts.only_merge_on_switching_branches = 0;

        opts.accept_pathspec = 1;
        opts.implicit_detach = 1;
 
        opts.accept_pathspec = 1;
        opts.implicit_detach = 1;
 


@@ -1666,6 +1547,7 @@ int cmd_switch(int argc, const char **argv, const char *prefix)
        opts.dwim_new_local_branch = 1;
        opts.accept_pathspec = 0;
        opts.switch_branch_doing_nothing_is_ok = 0;
        opts.dwim_new_local_branch = 1;
        opts.accept_pathspec = 0;
        opts.switch_branch_doing_nothing_is_ok = 0;

+       opts.only_merge_on_switching_branches = 1;

        opts.implicit_detach = 0;
 
        options = parse_options_dup(switch_options);
        opts.implicit_detach = 0;
 
        options = parse_options_dup(switch_options);

diff --git a/t/t1090-sparse-checkout-scope.sh b/t/t1090-sparse-checkout-scope.sh
index 090b7fc3d35d1a46a18b8ae385a7cc1213e6650d..40cc004326e2f0f66b74e2fbfa7d8a5cc21363a4 100755 (executable)
--- a/t/t1090-sparse-checkout-scope.sh
+++ b/t/t1090-sparse-checkout-scope.sh
@@ -31,20 +31,6 @@ test_expect_success 'perform sparse checkout of master' '
        test_path_is_file c
 '
 
        test_path_is_file c
 '
 

-test_expect_success 'checkout -b checkout.optimizeNewBranch interaction' '
-       cp .git/info/sparse-checkout .git/info/sparse-checkout.bak &&
-       test_when_finished "
-               mv -f .git/info/sparse-checkout.bak .git/info/sparse-checkout
-               git checkout master
-       " &&
-       echo "/b" >>.git/info/sparse-checkout &&
-       test "$(git ls-files -t b)" = "S b" &&
-       git -c checkout.optimizeNewBranch=true checkout -b fast &&
-       test "$(git ls-files -t b)" = "S b" &&
-       git checkout -b slow &&
-       test "$(git ls-files -t b)" = "H b"
-'
-

 test_expect_success 'merge feature branch into sparse checkout of master' '
        git merge feature &&
        test_path_is_file a &&
 test_expect_success 'merge feature branch into sparse checkout of master' '
        git merge feature &&
        test_path_is_file a &&