Merge branch 'nd/switch-and-restore'

Two new commands "git switch" and "git restore" are introduced to
split "checking out a branch to work on advancing its history" and
"checking out paths out of the index and/or a tree-ish to work on
advancing the current history" out of the single "git checkout"
command.

* nd/switch-and-restore: (46 commits)
  completion: disable dwim on "git switch -d"
  switch: allow to switch in the middle of bisect
  t2027: use test_must_be_empty
  Declare both git-switch and git-restore experimental
  help: move git-diff and git-reset to different groups
  doc: promote "git restore"
  user-manual.txt: prefer 'merge --abort' over 'reset --hard'
  completion: support restore
  t: add tests for restore
  restore: support --patch
  restore: replace --force with --ignore-unmerged
  restore: default to --source=HEAD when only --staged is specified
  restore: reject invalid combinations with --staged
  restore: add --worktree and --staged
  checkout: factor out worktree checkout code
  restore: disable overlay mode by default
  restore: make pathspec mandatory
  restore: take tree-ish from --source option instead
  checkout: split part of it to new command 'restore'
  doc: promote "git switch"
  ...

git-add--interactive.perl

@@ -149,6 +149,20 @@ my %patch_modes = (
 		FILTER => undef,
 		IS_REVERSE => 0,
 	},
+	'worktree_head' => {
+		DIFF => 'diff-index -p',
+		APPLY => sub { apply_patch 'apply -R', @_ },
+		APPLY_CHECK => 'apply -R',
+		FILTER => undef,
+		IS_REVERSE => 1,
+	},
+	'worktree_nothead' => {
+		DIFF => 'diff-index -R -p',
+		APPLY => sub { apply_patch 'apply', @_ },
+		APPLY_CHECK => 'apply',
+		FILTER => undef,
+		IS_REVERSE => 0,
+	},
 );
 
 $patch_mode = 'stage';
@@ -1053,6 +1067,12 @@ marked for discarding."),
 marked for discarding."),
 	checkout_nothead => N__(
 "If the patch applies cleanly, the edited hunk will immediately be
+marked for applying."),
+	worktree_head => N__(
+"If the patch applies cleanly, the edited hunk will immediately be
+marked for discarding."),
+	worktree_nothead => N__(
+"If the patch applies cleanly, the edited hunk will immediately be
 marked for applying."),
 );
 
@@ -1263,6 +1283,18 @@ d - do not discard this hunk or any of the later hunks in the file"),
 n - do not apply this hunk to index and worktree
 q - quit; do not apply this hunk or any of the remaining ones
 a - apply this hunk and all later hunks in the file
+d - do not apply this hunk or any of the later hunks in the file"),
+	worktree_head => N__(
+"y - discard this hunk from worktree
+n - do not discard this hunk from worktree
+q - quit; do not discard this hunk or any of the remaining ones
+a - discard this hunk and all later hunks in the file
+d - do not discard this hunk or any of the later hunks in the file"),
+	worktree_nothead => N__(
+"y - apply this hunk to worktree
+n - do not apply this hunk to worktree
+q - quit; do not apply this hunk or any of the remaining ones
+a - apply this hunk and all later hunks in the file
 d - do not apply this hunk or any of the later hunks in the file"),
 );
 
@@ -1425,6 +1457,16 @@ my %patch_update_prompt_modes = (
 		deletion => N__("Apply deletion to index and worktree [y,n,q,a,d%s,?]? "),
 		hunk => N__("Apply this hunk to index and worktree [y,n,q,a,d%s,?]? "),
 	},
+	worktree_head => {
+		mode => N__("Discard mode change from worktree [y,n,q,a,d%s,?]? "),
+		deletion => N__("Discard deletion from worktree [y,n,q,a,d%s,?]? "),
+		hunk => N__("Discard this hunk from worktree [y,n,q,a,d%s,?]? "),
+	},
+	worktree_nothead => {
+		mode => N__("Apply mode change to worktree [y,n,q,a,d%s,?]? "),
+		deletion => N__("Apply deletion to worktree [y,n,q,a,d%s,?]? "),
+		hunk => N__("Apply this hunk to worktree [y,n,q,a,d%s,?]? "),
+	},
 );
 
 sub patch_update_file {
@@ -1760,6 +1802,16 @@ sub process_args {
 						       'checkout_head' : 'checkout_nothead');
 					$arg = shift @ARGV or die __("missing --");
 				}
+			} elsif ($1 eq 'worktree') {
+				$arg = shift @ARGV or die __("missing --");
+				if ($arg eq '--') {
+					$patch_mode = 'checkout_index';
+				} else {
+					$patch_mode_revision = $arg;
+					$patch_mode = ($arg eq 'HEAD' ?
+						       'worktree_head' : 'worktree_nothead');
+					$arg = shift @ARGV or die __("missing --");
+				}
 			} elsif ($1 eq 'stage' or $1 eq 'stash') {
 				$patch_mode = $1;
 				$arg = shift @ARGV or die __("missing --");