reset: support "--mixed --intent-to-add" mode

When --mixed is used, entries could be removed from index if the
target ref does not have them. When "reset" is used in preparation for
commit spliting (in a dirty worktree), it could be hard to track what
files to be added back. The new option --intent-to-add simplifies it
by marking all removed files intent-to-add.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>

1 files changed, 28 insertions, 12 deletions

diff --git a/builtin/reset.c b/builtin/reset.c
index 60048030dd..4fd1c6c51d 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -116,25 +116,34 @@ static void update_index_from_diff(struct diff_queue_struct *q,
 		struct diff_options *opt, void *data)
 {
 	int i;
+	int intent_to_add = *(int *)data;
 
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filespec *one = q->queue[i]->one;
-		if (one->mode && !is_null_sha1(one->sha1)) {
-			struct cache_entry *ce;
-			ce = make_cache_entry(one->mode, one->sha1, one->path,
-				0, 0);
-			if (!ce)
-				die(_("make_cache_entry failed for path '%s'"),
-				    one->path);
-			add_cache_entry(ce, ADD_CACHE_OK_TO_ADD |
-				ADD_CACHE_OK_TO_REPLACE);
-		} else
+		int is_missing = !(one->mode && !is_null_sha1(one->sha1));
+		struct cache_entry *ce;
+
+		if (is_missing && !intent_to_add) {
 			remove_file_from_cache(one->path);
+			continue;
+		}
+
+		ce = make_cache_entry(one->mode, one->sha1, one->path,
+				      0, 0);
+		if (!ce)
+			die(_("make_cache_entry failed for path '%s'"),
+			    one->path);
+		if (is_missing) {
+			ce->ce_flags |= CE_INTENT_TO_ADD;
+			set_object_name_for_intent_to_add_entry(ce);
+		}
+		add_cache_entry(ce, ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE);
 	}
 }
 
 static int read_from_tree(const struct pathspec *pathspec,
-			  unsigned char *tree_sha1)
+			  unsigned char *tree_sha1,
+			  int intent_to_add)
 {
 	struct diff_options opt;
 
@@ -142,6 +151,7 @@ static int read_from_tree(const struct pathspec *pathspec,
 	copy_pathspec(&opt.pathspec, pathspec);
 	opt.output_format = DIFF_FORMAT_CALLBACK;
 	opt.format_callback = update_index_from_diff;
+	opt.format_callback_data = &intent_to_add;
 
 	if (do_diff_cache(tree_sha1, &opt))
 		return 1;
@@ -258,6 +268,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 	const char *rev;
 	unsigned char sha1[20];
 	struct pathspec pathspec;
+	int intent_to_add = 0;
 	const struct option options[] = {
 		OPT__QUIET(&quiet, N_("be quiet, only report errors")),
 		OPT_SET_INT(0, "mixed", &reset_type,
@@ -270,6 +281,8 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 		OPT_SET_INT(0, "keep", &reset_type,
 				N_("reset HEAD but keep local changes"), KEEP),
 		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_END()
 	};
 
@@ -327,6 +340,9 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 		die(_("%s reset is not allowed in a bare repository"),
 		    _(reset_type_names[reset_type]));
 
+	if (intent_to_add && reset_type != MIXED)
+		die(_("-N can only be used with --mixed"));
+
 	/* Soft reset does not touch the index file nor the working tree
 	 * at all, but requires them in a good order.  Other resets reset
 	 * the index file to the tree object we are switching to. */
@@ -338,7 +354,7 @@ int cmd_reset(int argc, const char **argv, const char *prefix)
 		int newfd = hold_locked_index(lock, 1);
 		if (reset_type == MIXED) {
 			int flags = quiet ? REFRESH_QUIET : REFRESH_IN_PORCELAIN;
-			if (read_from_tree(&pathspec, sha1))
+			if (read_from_tree(&pathspec, sha1, intent_to_add))
 				return 1;
 			refresh_index(&the_index, flags, NULL, NULL,
 				      _("Unstaged changes after reset:"));