Add "--patch" option to git-add--interactive

When the "--patch" option is supplied, the patch_update_cmd() function is
called bypassing the main_loop() and exits.

Seeing as builtin-add is the only caller of git-add--interactive we can
impose a strict requirement on the format of the arguments to avoid
possible ambiguity: an "--" argument must be used whenever any pathspecs
are passed, both with the "--patch" option and without it.

Signed-off-by: Wincent Colaiuta <win@wincent.com>

3 files changed, 65 insertions, 19 deletions

diff --git a/Documentation/git-add.txt b/Documentation/git-add.txt
index 63829d93cc..ce22de8d2e 100644
--- a/Documentation/git-add.txt
+++ b/Documentation/git-add.txt
@@ -61,7 +61,14 @@ OPTIONS
 
 -i, \--interactive::
 	Add modified contents in the working tree interactively to
-	the index.
+	the index. Optional path arguments may be supplied to limit
+	operation to a subset of the working tree. See ``Interactive
+	mode'' for details.
+
+-p, \--patch:
+	Similar to Interactive mode but the initial command loop is
+	bypassed and the 'patch' subcommand is invoked using each of
+	the specified filepatterns before exiting.
 
 -u::
 	Update only files that git already knows about. This is similar
diff --git a/builtin-add.c b/builtin-add.c
index 865c475ec9..5c29cc2f3f 100644
--- a/builtin-add.c
+++ b/builtin-add.c
@@ -19,7 +19,7 @@ static const char * const builtin_add_usage[] = {
 	"git-add [options] [--] <filepattern>...",
 	NULL
 };
-
+static int patch_interactive = 0, add_interactive = 0;
 static int take_worktree_changes;
 
 static void prune_directory(struct dir_struct *dir, const char **pathspec, int prefix)
@@ -144,7 +144,7 @@ static const char **validate_pathspec(int argc, const char **argv, const char *p
 
 int interactive_add(int argc, const char **argv, const char *prefix)
 {
-	int status;
+	int status, ac;
 	const char **args;
 	const char **pathspec = NULL;
 
@@ -154,11 +154,17 @@ int interactive_add(int argc, const char **argv, const char *prefix)
 			return -1;
 	}
 
-	args = xcalloc(sizeof(const char *), (argc + 2));
-	args[0] = "add--interactive";
-	if (argc)
-		memcpy(&(args[1]), pathspec, sizeof(const char *) * argc);
-	args[argc + 1] = NULL;
+	args = xcalloc(sizeof(const char *), (argc + 4));
+	ac = 0;
+	args[ac++] = "add--interactive";
+	if (patch_interactive)
+		args[ac++] = "--patch";
+	args[ac++] = "--";
+	if (argc) {
+		memcpy(&(args[ac]), pathspec, sizeof(const char *) * argc);
+		ac += argc;
+	}
+	args[ac] = NULL;
 
 	status = run_command_v_opt(args, RUN_GIT_CMD);
 	free(args);
@@ -171,13 +177,13 @@ static const char ignore_error[] =
 "The following paths are ignored by one of your .gitignore files:\n";
 
 static int verbose = 0, show_only = 0, ignored_too = 0, refresh_only = 0;
-static int add_interactive = 0;
 
 static struct option builtin_add_options[] = {
 	OPT__DRY_RUN(&show_only),
 	OPT__VERBOSE(&verbose),
 	OPT_GROUP(""),
 	OPT_BOOLEAN('i', "interactive", &add_interactive, "interactive picking"),
+	OPT_BOOLEAN('p', "patch", &patch_interactive, "interactive patching"),
 	OPT_BOOLEAN('f', NULL, &ignored_too, "allow adding otherwise ignored files"),
 	OPT_BOOLEAN('u', NULL, &take_worktree_changes, "update tracked files"),
 	OPT_BOOLEAN( 0 , "refresh", &refresh_only, "don't add, only refresh the index"),
@@ -192,6 +198,8 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 
 	argc = parse_options(argc, argv, builtin_add_options,
 			  builtin_add_usage, 0);
+	if (patch_interactive)
+		add_interactive = 1;
 	if (add_interactive)
 		exit(interactive_add(argc, argv, prefix));
 
diff --git a/git-add--interactive.perl b/git-add--interactive.perl
index e347216550..df5df3ec90 100755
--- a/git-add--interactive.perl
+++ b/git-add--interactive.perl
@@ -2,6 +2,9 @@
 
 use strict;
 
+# command line options
+my $patch_mode;
+
 sub run_cmd_pipe {
 	if ($^O eq 'MSWin32') {
 		my @invalid = grep {m/[":*]/} @_;
@@ -552,8 +555,8 @@ sub help_patch_cmd {
 	print <<\EOF ;
 y - stage this hunk
 n - do not stage this hunk
-a - stage this and all the remaining hunks
-d - do not stage this hunk nor any of the remaining hunks
+a - stage this and all the remaining hunks in the file
+d - do not stage this hunk nor any of the remaining hunks in the file
 j - leave this hunk undecided, see next undecided hunk
 J - leave this hunk undecided, see next hunk
 k - leave this hunk undecided, see previous undecided hunk
@@ -563,13 +566,21 @@ EOF
 }
 
 sub patch_update_cmd {
-	my @mods = list_modified('file-only');
-	@mods = grep { !($_->{BINARY}) } @mods;
-	return if (!@mods);
+	my @mods = grep { !($_->{BINARY}) } list_modified('file-only');
+	my @them;
 
-	my (@them) = list_and_choose({ PROMPT => 'Patch update',
-				       HEADER => $status_head, },
-				     @mods);
+	if (!@mods) {
+		print STDERR "No changes.\n";
+		return 0;
+	}
+	if ($patch_mode) {
+		@them = @mods;
+	}
+	else {
+		@them = list_and_choose({ PROMPT => 'Patch update',
+					  HEADER => $status_head, },
+					@mods);
+	}
 	for (@them) {
 		patch_update_file($_->{VALUE});
 	}
@@ -783,6 +794,20 @@ add untracked - add contents of untracked files to the staged set of changes
 EOF
 }
 
+sub process_args {
+	return unless @ARGV;
+	my $arg = shift @ARGV;
+	if ($arg eq "--patch") {
+		$patch_mode = 1;
+		$arg = shift @ARGV or die "missing --";
+		die "invalid argument $arg, expecting --"
+		    unless $arg eq "--";
+	}
+	elsif ($arg ne "--") {
+		die "invalid argument $arg, expecting --";
+	}
+}
+
 sub main_loop {
 	my @cmd = ([ 'status', \&status_cmd, ],
 		   [ 'update', \&update_cmd, ],
@@ -811,6 +836,12 @@ sub main_loop {
 	}
 }
 
+process_args();
 refresh();
-status_cmd();
-main_loop();
+if ($patch_mode) {
+	patch_update_cmd();
+}
+else {
+	status_cmd();
+	main_loop();
+}