Implement 'git reset --patch'

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 @@ sub colored {
                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 @@ sub help_cmd {
 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 --";