Merge branch 'tr/reset-checkout-patch'

* tr/reset-checkout-patch:
  stash: simplify defaulting to "save" and reject unknown options
  Make test case number unique
  tests: disable interactive hunk selection tests if perl is not available
  DWIM 'git stash save -p' for 'git stash -p'
  Implement 'git stash save --patch'
  Implement 'git checkout --patch'
  Implement 'git reset --patch'
  builtin-add: refactor the meat of interactive_add()
  Add a small patch-mode testing library
  git-apply--interactive: Refactor patch mode code
  Make 'git stash -k' a short form for 'git stash save --keep-index'

Documentation/git-checkout.txt

@@ -11,6 +11,7 @@ SYNOPSIS
 'git checkout' [-q] [-f] [-m] [<branch>]
 'git checkout' [-q] [-f] [-m] [-b <new_branch>] [<start_point>]
 'git checkout' [-f|--ours|--theirs|-m|--conflict=<style>] [<tree-ish>] [--] <paths>...
+'git checkout' --patch [<tree-ish>] [--] [<paths>...]
 
 DESCRIPTION
 -----------
@@ -25,7 +26,7 @@ use the --track or --no-track options, which will be passed to `git
 branch`.  As a convenience, --track without `-b` implies branch
 creation; see the description of --track below.
 
-When <paths> are given, this command does *not* switch
+When <paths> or --patch are given, this command does *not* switch
 branches.  It updates the named paths in the working tree from
 the index file, or from a named <tree-ish> (most often a commit).  In
 this case, the `-b` and `--track` options are meaningless and giving
@@ -115,6 +116,16 @@ the conflicted merge in the specified paths.
 	"merge" (default) and "diff3" (in addition to what is shown by
 	"merge" style, shows the original contents).
 
+-p::
+--patch::
+	Interactively select hunks in the difference between the
+	<tree-ish> (or the index, if unspecified) and the working
+	tree.  The chosen hunks are then applied in reverse to the
+	working tree (and if a <tree-ish> was specified, the index).
++
+This means that you can use `git checkout -p` to selectively discard
+edits from your current working tree.
+
 <branch>::
 	Branch to checkout; if it refers to a branch (i.e., a name that,
 	when prepended with "refs/heads/", is a valid ref), then that

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.
 

Documentation/git-stash.txt

@@ -13,7 +13,7 @@ SYNOPSIS
 'git stash' drop [-q|--quiet] [<stash>]
 'git stash' ( pop | apply ) [--index] [-q|--quiet] [<stash>]
 'git stash' branch <branchname> [<stash>]
-'git stash' [save [--keep-index] [-q|--quiet] [<message>]]
+'git stash' [save [--patch] [-k|--[no-]keep-index] [-q|--quiet] [<message>]]
 'git stash' clear
 'git stash' create
 
@@ -42,15 +42,27 @@ is also possible).
 OPTIONS
 -------
 
-save [--keep-index] [-q|--quiet] [<message>]::
+save [--patch] [--[no-]keep-index] [-q|--quiet] [<message>]::
 
 	Save your local modifications to a new 'stash', and run `git reset
-	--hard` to revert them.  This is the default action when no
-	subcommand is given. The <message> part is optional and gives
-	the description along with the stashed state.
+	--hard` to revert them.  The <message> part is optional and gives
+	the description along with the stashed state.  For quickly making
+	a snapshot, you can omit _both_ "save" and <message>, but giving
+	only <message> does not trigger this action to prevent a misspelled
+	subcommand from making an unwanted stash.
 +
 If the `--keep-index` option is used, all changes already added to the
 index are left intact.
++
+With `--patch`, you can interactively select hunks from in the diff
+between HEAD and the working tree to be stashed.  The stash entry is
+constructed such that its index state is the same as the index state
+of your repository, and its worktree contains only the changes you
+selected interactively.  The selected changes are then rolled back
+from your worktree.
++
+The `--patch` option implies `--keep-index`.  You can use
+`--no-keep-index` to override this.
 
 list [<options>]::
 

builtin-add.c

@@ -131,27 +131,27 @@ static const char **validate_pathspec(int argc, const char **argv, const char *p
 	return pathspec;
 }
 
-int interactive_add(int argc, const char **argv, const char *prefix)
+int run_add_interactive(const char *revision, const char *patch_mode,
+			const char **pathspec)
 {
-	int status, ac;
+	int status, ac, pc = 0;
 	const char **args;
-	const char **pathspec = NULL;
 
-	if (argc) {
-		pathspec = validate_pathspec(argc, argv, prefix);
-		if (!pathspec)
-			return -1;
-	}
+	if (pathspec)
+		while (pathspec[pc])
+			pc++;
 
-	args = xcalloc(sizeof(const char *), (argc + 4));
+	args = xcalloc(sizeof(const char *), (pc + 5));
 	ac = 0;
 	args[ac++] = "add--interactive";
-	if (patch_interactive)
-		args[ac++] = "--patch";
+	if (patch_mode)
+		args[ac++] = patch_mode;
+	if (revision)
+		args[ac++] = revision;
 	args[ac++] = "--";
-	if (argc) {
-		memcpy(&(args[ac]), pathspec, sizeof(const char *) * argc);
-		ac += argc;
+	if (pc) {
+		memcpy(&(args[ac]), pathspec, sizeof(const char *) * pc);
+		ac += pc;
 	}
 	args[ac] = NULL;
 
@@ -160,6 +160,21 @@ int interactive_add(int argc, const char **argv, const char *prefix)
 	return status;
 }
 
+int interactive_add(int argc, const char **argv, const char *prefix)
+{
+	const char **pathspec = NULL;
+
+	if (argc) {
+		pathspec = validate_pathspec(argc, argv, prefix);
+		if (!pathspec)
+			return -1;
+	}
+
+	return run_add_interactive(NULL,
+				   patch_interactive ? "--patch" : NULL,
+				   pathspec);
+}
+
 static int edit_patch(int argc, const char **argv, const char *prefix)
 {
 	char *file = xstrdup(git_path("ADD_EDIT.patch"));

builtin-checkout.c

@@ -566,6 +566,13 @@ static int git_checkout_config(const char *var, const char *value, void *cb)
 	return git_xmerge_config(var, value, cb);
 }
 
+static int interactive_checkout(const char *revision, const char **pathspec,
+				struct checkout_opts *opts)
+{
+	return run_add_interactive(revision, "--patch=checkout", pathspec);
+}
+
+
 int cmd_checkout(int argc, const char **argv, const char *prefix)
 {
 	struct checkout_opts opts;
@@ -574,6 +581,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	struct branch_info new;
 	struct tree *source_tree = NULL;
 	char *conflict_style = NULL;
+	int patch_mode = 0;
 	struct option options[] = {
 		OPT__QUIET(&opts.quiet),
 		OPT_STRING('b', NULL, &opts.new_branch, "new branch", "branch"),
@@ -588,6 +596,7 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		OPT_BOOLEAN('m', "merge", &opts.merge, "merge"),
 		OPT_STRING(0, "conflict", &conflict_style, "style",
 			   "conflict style (merge or diff3)"),
+		OPT_BOOLEAN('p', "patch", &patch_mode, "select hunks interactively"),
 		OPT_END(),
 	};
 	int has_dash_dash;
@@ -602,6 +611,10 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 	argc = parse_options(argc, argv, prefix, options, checkout_usage,
 			     PARSE_OPT_KEEP_DASHDASH);
 
+	if (patch_mode && (opts.track > 0 || opts.new_branch
+			   || opts.new_branch_log || opts.merge || opts.force))
+		die ("--patch is incompatible with all other options");
+
 	/* --track without -b should DWIM */
 	if (0 < opts.track && !opts.new_branch) {
 		const char *argv0 = argv[0];
@@ -708,6 +721,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		if (!pathspec)
 			die("invalid path specification");
 
+		if (patch_mode)
+			return interactive_checkout(new.name, pathspec, &opts);
+
 		/* Checkout paths */
 		if (opts.new_branch) {
 			if (argc == 1) {
@@ -723,6 +739,9 @@ int cmd_checkout(int argc, const char **argv, const char *prefix)
 		return checkout_paths(source_tree, pathspec, &opts);
 	}
 
+	if (patch_mode)
+		return interactive_checkout(new.name, NULL, &opts);
+
 	if (opts.new_branch) {
 		struct strbuf buf = STRBUF_INIT;
 		if (strbuf_check_branch_ref(&buf, opts.new_branch))

builtin-reset.c

@@ -143,6 +143,17 @@ 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)
 {
@@ -184,6 +195,7 @@ 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];
@@ -199,6 +211,7 @@ 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()
 	};
 
@@ -252,6 +265,12 @@ 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. */

commit.h

@@ -140,6 +140,8 @@ int is_descendant_of(struct commit *, struct commit_list *);
 int in_merge_bases(struct commit *, struct commit **, int);
 
 extern int interactive_add(int argc, const char **argv, const char *prefix);
+extern int run_add_interactive(const char *revision, const char *patch_mode,
+			       const char **pathspec);
 
 static inline int single_parent(struct commit *commit)
 {