Merge branch 'reset-stdin'

This topic branch adds the (experimental) --stdin/-z options to `git
reset`. Those patches are still under review in the upstream Git project,
but are already merged in their experimental form into Git for Windows'
`master` branch, in preparation for a MinGit-only release.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Documentation/git-reset.txt

@@ -10,6 +10,7 @@ SYNOPSIS
 [verse]
 'git reset' [-q] [<tree-ish>] [--] <paths>...
 'git reset' (--patch | -p) [<tree-ish>] [--] [<paths>...]
+EXPERIMENTAL: 'git reset' [-q] [--stdin [-z]] [<tree-ish>]
 'git reset' [--soft | --mixed [-N] | --hard | --merge | --keep] [-q] [<commit>]
 
 DESCRIPTION
@@ -100,6 +101,15 @@ OPTIONS
 	`reset.quiet` config option. `--quiet` and `--no-quiet` will
 	override the default behavior.
 
+--stdin::
+	EXPERIMENTAL: Instead of taking list of paths from the
+	command line, read list of paths from the standard input.
+	Paths are separated by LF (i.e. one path per line) by
+	default.
+
+-z::
+	EXPERIMENTAL: Only meaningful with `--stdin`; paths are
+	separated with NUL character instead of LF.
 
 EXAMPLES
 --------

builtin/reset.c

@@ -24,12 +24,15 @@
 #include "cache-tree.h"
 #include "submodule.h"
 #include "submodule-config.h"
+#include "strbuf.h"
+#include "quote.h"
 
 #define REFRESH_INDEX_DELAY_WARNING_IN_MS (2 * 1000)
 
 static const char * const git_reset_usage[] = {
 	N_("git reset [--mixed | --soft | --hard | --merge | --keep] [-q] [<commit>]"),
 	N_("git reset [-q] [<tree-ish>] [--] <paths>..."),
+	N_("EXPERIMENTAL: git reset [-q] [--stdin [-z]] [<tree-ish>]"),
 	N_("git reset --patch [<tree-ish>] [--] [<paths>...]"),
 	NULL
 };
@@ -283,7 +286,9 @@ static int git_reset_config(const char *var, const char *value, void *cb)
 int cmd_reset(int argc, const char **argv, const char *prefix)
 {
 	int reset_type = NONE, update_ref_status = 0, quiet = 0;
-	int patch_mode = 0, unborn;
+	int patch_mode = 0, nul_term_line = 0, read_from_stdin = 0, unborn;
+	char **stdin_paths = NULL;
+	int stdin_nr = 0, stdin_alloc = 0;
 	const char *rev;
 	struct object_id oid;
 	struct pathspec pathspec;
@@ -305,6 +310,10 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 		OPT_BOOL('p', "patch", &patch_mode, N_("select hunks interactively")),
 		OPT_BOOL('N', "intent-to-add", &intent_to_add,
 				N_("record only the fact that removed paths will be added later")),
+		OPT_BOOL('z', NULL, &nul_term_line,
+			N_("EXPERIMENTAL: paths are separated with NUL character")),
+		OPT_BOOL(0, "stdin", &read_from_stdin,
+				N_("EXPERIMENTAL: read paths from <stdin>")),
 		OPT_END()
 	};
 
@@ -315,6 +324,42 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 						PARSE_OPT_KEEP_DASHDASH);
 	parse_args(&pathspec, argv, prefix, patch_mode, &rev);
 
+	if (read_from_stdin) {
+		strbuf_getline_fn getline_fn = nul_term_line ?
+			strbuf_getline_nul : strbuf_getline_lf;
+		int flags = PATHSPEC_PREFER_FULL;
+		struct strbuf buf = STRBUF_INIT;
+		struct strbuf unquoted = STRBUF_INIT;
+
+		if (patch_mode)
+			die(_("--stdin is incompatible with --patch"));
+
+		if (pathspec.nr)
+			die(_("--stdin is incompatible with path arguments"));
+
+		while (getline_fn(&buf, stdin) != EOF) {
+			if (!nul_term_line && buf.buf[0] == '"') {
+				strbuf_reset(&unquoted);
+				if (unquote_c_style(&unquoted, buf.buf, NULL))
+					die(_("line is badly quoted"));
+				strbuf_swap(&buf, &unquoted);
+			}
+			ALLOC_GROW(stdin_paths, stdin_nr + 1, stdin_alloc);
+			stdin_paths[stdin_nr++] = xstrdup(buf.buf);
+			strbuf_reset(&buf);
+		}
+		strbuf_release(&unquoted);
+		strbuf_release(&buf);
+
+		ALLOC_GROW(stdin_paths, stdin_nr + 1, stdin_alloc);
+		stdin_paths[stdin_nr++] = NULL;
+		flags |= PATHSPEC_LITERAL_PATH;
+		parse_pathspec(&pathspec, 0, flags, prefix,
+			       (const char **)stdin_paths);
+
+	} else if (nul_term_line)
+		die(_("-z requires --stdin"));
+
 	unborn = !strcmp(rev, "HEAD") && get_oid("HEAD", &oid);
 	if (unborn) {
 		/* reset on unborn branch: treat as reset to empty tree */
@@ -415,5 +460,11 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 	if (!pathspec.nr)
 		remove_branch_state();
 
+	if (stdin_paths) {
+		while (stdin_nr)
+			free(stdin_paths[--stdin_nr]);
+		free(stdin_paths);
+	}
+
 	return update_ref_status;
 }

t/t7108-reset-stdin.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+test_description='reset --stdin'
+
+. ./test-lib.sh
+
+test_expect_success 'reset --stdin' '
+	test_commit hello &&
+	git rm hello.t &&
+	test -z "$(git ls-files hello.t)" &&
+	echo hello.t | git reset --stdin &&
+	test hello.t = "$(git ls-files hello.t)"
+'
+
+test_expect_success 'reset --stdin -z' '
+	test_commit world &&
+	git rm hello.t world.t &&
+	test -z "$(git ls-files hello.t world.t)" &&
+	printf world.tQworld.tQhello.tQ | q_to_nul | git reset --stdin -z &&
+	printf "hello.t\nworld.t\n" >expect &&
+	git ls-files >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success '--stdin requires --mixed' '
+	echo hello.t >list &&
+	test_must_fail git reset --soft --stdin <list &&
+	test_must_fail git reset --hard --stdin <list &&
+	git reset --mixed --stdin <list
+'
+
+test_done