Implement 'git reset --patch'

This introduces a --patch mode for git-reset.  The basic case is

  git reset --patch -- [files...]

which acts as the opposite of 'git add --patch -- [files...]': it
offers hunks for *un*staging.  Advanced usage is

  git reset --patch <revision> -- [files...]

which offers hunks from the diff between the index and <revision> for
forward application to the index.  (That is, the basic case is just
<revision> = HEAD.)

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
index abb25d1c00c97144b1f3709e408fe9cad613e623..469cf6dbacb8de24b5dd0dd78d63dd9ecc8fbd01 100644 (file)
--- a/Documentation/git-reset.txt
+++ b/Documentation/git-reset.txt
@@ -10,6 +10,7 @@ SYNOPSIS
 [verse]
 'git reset' [--mixed | --soft | --hard | --merge] [-q] [<commit>]
 'git reset' [-q] [<commit>] [--] <paths>...
+'git reset' --patch [<commit>] [--] [<paths>...]
 
 DESCRIPTION
 -----------
@@ -23,8 +24,9 @@ the undo in the history.
 If you want to undo a commit other than the latest on a branch,
 linkgit:git-revert[1] is your friend.
 
-The second form with 'paths' is used to revert selected paths in
-the index from a given commit, without moving HEAD.
+The second and third forms with 'paths' and/or --patch are used to
+revert selected paths in the index from a given commit, without moving
+HEAD.
 
 
 OPTIONS
@@ -50,6 +52,15 @@ OPTIONS
        and updates the files that are different between the named commit
        and the current commit in the working tree.
 
+-p::
+--patch::
+       Interactively select hunks in the difference between the index
+       and <commit> (defaults to HEAD).  The chosen hunks are applied
+       in reverse to the index.
++
+This means that `git reset -p` is the opposite of `git add -p` (see
+linkgit:git-add[1]).
+
 -q::
        Be quiet, only report errors.
 

diff --git a/builtin-reset.c b/builtin-reset.c
index 5fa1789d0c2b90ef9ee83d091b67292f2ff0db26..246a127b5f1b0a4935e1cbcb79ce3c4f4b538e6d 100644 (file)
--- a/builtin-reset.c
+++ b/builtin-reset.c
@@ -142,6 +142,17 @@ static void update_index_from_diff(struct diff_queue_struct *q,
        }
 }
 
+static int interactive_reset(const char *revision, const char **argv,
+                            const char *prefix)
+{
+       const char **pathspec = NULL;
+
+       if (*argv)
+               pathspec = get_pathspec(prefix, argv);
+
+       return run_add_interactive(revision, "--patch=reset", pathspec);
+}
+
 static int read_from_tree(const char *prefix, const char **argv,
                unsigned char *tree_sha1, int refresh_flags)
 {
@@ -183,6 +194,7 @@ static void prepend_reflog_action(const char *action, char *buf, size_t size)
 int cmd_reset(int argc, const char **argv, const char *prefix)
 {
        int i = 0, reset_type = NONE, update_ref_status = 0, quiet = 0;
+       int patch_mode = 0;
        const char *rev = "HEAD";
        unsigned char sha1[20], *orig = NULL, sha1_orig[20],
                                *old_orig = NULL, sha1_old_orig[20];
@@ -198,6 +210,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                                "reset HEAD, index and working tree", MERGE),
                OPT_BOOLEAN('q', NULL, &quiet,
                                "disable showing new HEAD in hard reset and progress message"),
+               OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
                OPT_END()
        };
 
@@ -251,6 +264,12 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
                die("Could not parse object '%s'.", rev);
        hashcpy(sha1, commit->object.sha1);
 
+       if (patch_mode) {
+               if (reset_type != NONE)
+                       die("--patch is incompatible with --{hard,mixed,soft}");
+               return interactive_reset(rev, argv + i, prefix);
+       }
+
        /* git reset tree [--] paths... can be used to
         * load chosen paths from the tree into the index without
         * affecting the working tree nor HEAD. */

diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index 360610314e8e98c4c79a86273696317bf44cb1dd..d14f48c8379cb287e2e1bbe9c8fb7946e6b160fe 100755 (executable)
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -72,6 +72,7 @@ sub colored {
 
 # command line options
 my $patch_mode;
+my $patch_mode_revision;
 
 sub apply_patch;
 
@@ -85,6 +86,24 @@ my %patch_modes = (
                PARTICIPLE => 'staging',
                FILTER => 'file-only',
        },
+       'reset_head' => {
+               DIFF => 'diff-index -p --cached',
+               APPLY => sub { apply_patch 'apply -R --cached', @_; },
+               APPLY_CHECK => 'apply -R --cached',
+               VERB => 'Unstage',
+               TARGET => '',
+               PARTICIPLE => 'unstaging',
+               FILTER => 'index-only',
+       },
+       'reset_nothead' => {
+               DIFF => 'diff-index -R -p --cached',
+               APPLY => sub { apply_patch 'apply --cached', @_; },
+               APPLY_CHECK => 'apply --cached',
+               VERB => 'Apply',
+               TARGET => ' to index',
+               PARTICIPLE => 'applying',
+               FILTER => 'index-only',
+       },
 );
 
 my %patch_mode_flavour = %{$patch_modes{stage}};
@@ -206,7 +225,14 @@ sub list_modified {
                return if (!@tracked);
        }
 
-       my $reference = is_initial_commit() ? get_empty_tree() : 'HEAD';
+       my $reference;
+       if (defined $patch_mode_revision and $patch_mode_revision ne 'HEAD') {
+               $reference = $patch_mode_revision;
+       } elsif (is_initial_commit()) {
+               $reference = get_empty_tree();
+       } else {
+               $reference = 'HEAD';
+       }
        for (run_cmd_pipe(qw(git diff-index --cached
                             --numstat --summary), $reference,
                             '--', @tracked)) {
@@ -640,6 +666,9 @@ sub run_git_apply {
 sub parse_diff {
        my ($path) = @_;
        my @diff_cmd = split(" ", $patch_mode_flavour{DIFF});
+       if (defined $patch_mode_revision) {
+               push @diff_cmd, $patch_mode_revision;
+       }
        my @diff = run_cmd_pipe("git", @diff_cmd, "--", $path);
        my @colored = ();
        if ($diff_use_color) {
@@ -1391,11 +1420,31 @@ EOF
 sub process_args {
        return unless @ARGV;
        my $arg = shift @ARGV;
-       if ($arg eq "--patch") {
-               $patch_mode = 1;
-               $arg = shift @ARGV or die "missing --";
+       if ($arg =~ /--patch(?:=(.*))?/) {
+               if (defined $1) {
+                       if ($1 eq 'reset') {
+                               $patch_mode = 'reset_head';
+                               $patch_mode_revision = 'HEAD';
+                               $arg = shift @ARGV or die "missing --";
+                               if ($arg ne '--') {
+                                       $patch_mode_revision = $arg;
+                                       $patch_mode = ($arg eq 'HEAD' ?
+                                                      'reset_head' : 'reset_nothead');
+                                       $arg = shift @ARGV or die "missing --";
+                               }
+                       } elsif ($1 eq 'stage') {
+                               $patch_mode = 'stage';
+                               $arg = shift @ARGV or die "missing --";
+                       } else {
+                               die "unknown --patch mode: $1";
+                       }
+               } else {
+                       $patch_mode = 'stage';
+                       $arg = shift @ARGV or die "missing --";
+               }
                die "invalid argument $arg, expecting --"
                    unless $arg eq "--";
+               %patch_mode_flavour = %{$patch_modes{$patch_mode}};
        }
        elsif ($arg ne "--") {
                die "invalid argument $arg, expecting --";

diff --git a/t/t7105-reset-patch.sh b/t/t7105-reset-patch.sh
new file mode 100755 (executable)
index 0000000..c1f4fc3
--- /dev/null
+++ b/t/t7105-reset-patch.sh
@@ -0,0 +1,69 @@
+#!/bin/sh
+
+test_description='git reset --patch'
+. ./lib-patch-mode.sh
+
+test_expect_success 'setup' '
+       mkdir dir &&
+       echo parent > dir/foo &&
+       echo dummy > bar &&
+       git add dir &&
+       git commit -m initial &&
+       test_tick &&
+       test_commit second dir/foo head &&
+       set_and_save_state bar bar_work bar_index &&
+       save_head
+'
+
+# note: bar sorts before foo, so the first 'n' is always to skip 'bar'
+
+test_expect_success 'saying "n" does nothing' '
+       set_and_save_state dir/foo work work
+       (echo n; echo n) | git reset -p &&
+       verify_saved_state dir/foo &&
+       verify_saved_state bar
+'
+
+test_expect_success 'git reset -p' '
+       (echo n; echo y) | git reset -p &&
+       verify_state dir/foo work head &&
+       verify_saved_state bar
+'
+
+test_expect_success 'git reset -p HEAD^' '
+       (echo n; echo y) | git reset -p HEAD^ &&
+       verify_state dir/foo work parent &&
+       verify_saved_state bar
+'
+
+# The idea in the rest is that bar sorts first, so we always say 'y'
+# first and if the path limiter fails it'll apply to bar instead of
+# dir/foo.  There's always an extra 'n' to reject edits to dir/foo in
+# the failure case (and thus get out of the loop).
+
+test_expect_success 'git reset -p dir' '
+       set_state dir/foo work work
+       (echo y; echo n) | git reset -p dir &&
+       verify_state dir/foo work head &&
+       verify_saved_state bar
+'
+
+test_expect_success 'git reset -p -- foo (inside dir)' '
+       set_state dir/foo work work
+       (echo y; echo n) | (cd dir && git reset -p -- foo) &&
+       verify_state dir/foo work head &&
+       verify_saved_state bar
+'
+
+test_expect_success 'git reset -p HEAD^ -- dir' '
+       (echo y; echo n) | git reset -p HEAD^ -- dir &&
+       verify_state dir/foo work parent &&
+       verify_saved_state bar
+'
+
+test_expect_success 'none of this moved HEAD' '
+       verify_saved_head
+'
+
+
+test_done