merge(3p/git): Merge git subtree at v2.29.2 r/1890

This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb

1 files changed, 165 insertions, 188 deletions

diff --git a/third_party/git/builtin/stash.c b/third_party/git/builtin/stash.c
index b5a301f24d..3f811f3050 100644
--- a/third_party/git/builtin/stash.c
+++ b/third_party/git/builtin/stash.c
@@ -7,7 +7,7 @@
 #include "cache-tree.h"
 #include "unpack-trees.h"
 #include "merge-recursive.h"
-#include "argv-array.h"
+#include "strvec.h"
 #include "run-command.h"
 #include "dir.h"
 #include "rerere.h"
@@ -27,6 +27,7 @@ static const char * const git_stash_usage[] = {
 	N_("git stash clear"),
 	N_("git stash [push [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]\n"
 	   "          [-u|--include-untracked] [-a|--all] [-m|--message <message>]\n"
+	   "          [--pathspec-from-file=<file> [--pathspec-file-nul]]\n"
 	   "          [--] [<pathspec>...]]"),
 	N_("git stash save [-p|--patch] [-k|--[no-]keep-index] [-q|--quiet]\n"
 	   "          [-u|--include-untracked] [-a|--all] [<message>]"),
@@ -184,7 +185,7 @@ static int get_stash_info(struct stash_info *info, int argc, const char **argv)
 	end_of_rev = strchrnul(revision, '@');
 	strbuf_add(&symbolic, revision, end_of_rev - revision);
 
-	ret = dwim_ref(symbolic.buf, symbolic.len, &dummy, &expanded_ref);
+	ret = dwim_ref(symbolic.buf, symbolic.len, &dummy, &expanded_ref, 0);
 	strbuf_release(&symbolic);
 	switch (ret) {
 	case 0: /* Not found, but valid ref */
@@ -276,8 +277,8 @@ static int diff_tree_binary(struct strbuf *out, struct object_id *w_commit)
 	 * however it should be done together with apply_cached.
 	 */
 	cp.git_cmd = 1;
-	argv_array_pushl(&cp.args, "diff-tree", "--binary", NULL);
-	argv_array_pushf(&cp.args, "%s^2^..%s^2", w_commit_hex, w_commit_hex);
+	strvec_pushl(&cp.args, "diff-tree", "--binary", NULL);
+	strvec_pushf(&cp.args, "%s^2^..%s^2", w_commit_hex, w_commit_hex);
 
 	return pipe_command(&cp, NULL, 0, out, 0, NULL, 0);
 }
@@ -292,7 +293,7 @@ static int apply_cached(struct strbuf *out)
 	 * buffer.
 	 */
 	cp.git_cmd = 1;
-	argv_array_pushl(&cp.args, "apply", "--cached", NULL);
+	strvec_pushl(&cp.args, "apply", "--cached", NULL);
 	return pipe_command(&cp, out->buf, out->len, NULL, 0, NULL, 0);
 }
 
@@ -305,7 +306,7 @@ static int reset_head(void)
 	 * API for resetting.
 	 */
 	cp.git_cmd = 1;
-	argv_array_push(&cp.args, "reset");
+	strvec_push(&cp.args, "reset");
 
 	return run_command(&cp);
 }
@@ -334,9 +335,9 @@ static int get_newly_staged(struct strbuf *out, struct object_id *c_tree)
 	 * converted together with update_index.
 	 */
 	cp.git_cmd = 1;
-	argv_array_pushl(&cp.args, "diff-index", "--cached", "--name-only",
-			 "--diff-filter=A", NULL);
-	argv_array_push(&cp.args, c_tree_hex);
+	strvec_pushl(&cp.args, "diff-index", "--cached", "--name-only",
+		     "--diff-filter=A", NULL);
+	strvec_push(&cp.args, c_tree_hex);
 	return pipe_command(&cp, NULL, 0, out, 0, NULL, 0);
 }
 
@@ -349,7 +350,7 @@ static int update_index(struct strbuf *out)
 	 * function exposed in order to remove this forking.
 	 */
 	cp.git_cmd = 1;
-	argv_array_pushl(&cp.args, "update-index", "--add", "--stdin", NULL);
+	strvec_pushl(&cp.args, "update-index", "--add", "--stdin", NULL);
 	return pipe_command(&cp, out->buf, out->len, NULL, 0, NULL, 0);
 }
 
@@ -364,10 +365,10 @@ static int restore_untracked(struct object_id *u_tree)
 	 * run_command to fork processes that will not interfere.
 	 */
 	cp.git_cmd = 1;
-	argv_array_push(&cp.args, "read-tree");
-	argv_array_push(&cp.args, oid_to_hex(u_tree));
-	argv_array_pushf(&cp.env_array, "GIT_INDEX_FILE=%s",
-			 stash_index_path.buf);
+	strvec_push(&cp.args, "read-tree");
+	strvec_push(&cp.args, oid_to_hex(u_tree));
+	strvec_pushf(&cp.env_array, "GIT_INDEX_FILE=%s",
+		     stash_index_path.buf);
 	if (run_command(&cp)) {
 		remove_path(stash_index_path.buf);
 		return -1;
@@ -375,9 +376,9 @@ static int restore_untracked(struct object_id *u_tree)
 
 	child_process_init(&cp);
 	cp.git_cmd = 1;
-	argv_array_pushl(&cp.args, "checkout-index", "--all", NULL);
-	argv_array_pushf(&cp.env_array, "GIT_INDEX_FILE=%s",
-			 stash_index_path.buf);
+	strvec_pushl(&cp.args, "checkout-index", "--all", NULL);
+	strvec_pushf(&cp.env_array, "GIT_INDEX_FILE=%s",
+		     stash_index_path.buf);
 
 	res = run_command(&cp);
 	remove_path(stash_index_path.buf);
@@ -396,7 +397,7 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
 	const struct object_id *bases[1];
 
 	read_cache_preload(NULL);
-	if (refresh_cache(REFRESH_QUIET))
+	if (refresh_and_write_cache(REFRESH_QUIET, 0, 0))
 		return -1;
 
 	if (write_cache_as_tree(&c_tree, 0, NULL))
@@ -427,6 +428,8 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
 				return error(_("could not save index tree"));
 
 			reset_head();
+			discard_cache();
+			read_cache();
 		}
 	}
 
@@ -481,13 +484,12 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
 		if (ret)
 			return -1;
 
+		/* read back the result of update_index() back from the disk */
 		discard_cache();
+		read_cache();
 	}
 
-	if (quiet) {
-		if (refresh_cache(REFRESH_QUIET))
-			warning("could not refresh index");
-	} else {
+	if (!quiet) {
 		struct child_process cp = CHILD_PROCESS_INIT;
 
 		/*
@@ -497,7 +499,11 @@ static int do_apply_stash(const char *prefix, struct stash_info *info,
 		 */
 		cp.git_cmd = 1;
 		cp.dir = prefix;
-		argv_array_push(&cp.args, "status");
+		strvec_pushf(&cp.env_array, GIT_WORK_TREE_ENVIRONMENT"=%s",
+			     absolute_path(get_git_work_tree()));
+		strvec_pushf(&cp.env_array, GIT_DIR_ENVIRONMENT"=%s",
+			     absolute_path(get_git_dir()));
+		strvec_push(&cp.args, "status");
 		run_command(&cp);
 	}
 
@@ -540,9 +546,9 @@ static int do_drop_stash(struct stash_info *info, int quiet)
 	 */
 
 	cp_reflog.git_cmd = 1;
-	argv_array_pushl(&cp_reflog.args, "reflog", "delete", "--updateref",
-			 "--rewrite", NULL);
-	argv_array_push(&cp_reflog.args, info->revision.buf);
+	strvec_pushl(&cp_reflog.args, "reflog", "delete", "--updateref",
+		     "--rewrite", NULL);
+	strvec_push(&cp_reflog.args, info->revision.buf);
 	ret = run_command(&cp_reflog);
 	if (!ret) {
 		if (!quiet)
@@ -560,8 +566,8 @@ static int do_drop_stash(struct stash_info *info, int quiet)
 	cp.git_cmd = 1;
 	/* Even though --quiet is specified, rev-parse still outputs the hash */
 	cp.no_stdout = 1;
-	argv_array_pushl(&cp.args, "rev-parse", "--verify", "--quiet", NULL);
-	argv_array_pushf(&cp.args, "%s@{0}", ref_stash);
+	strvec_pushl(&cp.args, "rev-parse", "--verify", "--quiet", NULL);
+	strvec_pushf(&cp.args, "%s@{0}", ref_stash);
 	ret = run_command(&cp);
 
 	/* do_clear_stash if we just dropped the last stash entry */
@@ -657,9 +663,9 @@ static int branch_stash(int argc, const char **argv, const char *prefix)
 		return -1;
 
 	cp.git_cmd = 1;
-	argv_array_pushl(&cp.args, "checkout", "-b", NULL);
-	argv_array_push(&cp.args, branch);
-	argv_array_push(&cp.args, oid_to_hex(&info.b_commit));
+	strvec_pushl(&cp.args, "checkout", "-b", NULL);
+	strvec_push(&cp.args, branch);
+	strvec_push(&cp.args, oid_to_hex(&info.b_commit));
 	ret = run_command(&cp);
 	if (!ret)
 		ret = do_apply_stash(prefix, &info, 1, 0);
@@ -686,16 +692,17 @@ static int list_stash(int argc, const char **argv, const char *prefix)
 		return 0;
 
 	cp.git_cmd = 1;
-	argv_array_pushl(&cp.args, "log", "--format=%gd: %gs", "-g",
-			 "--first-parent", "-m", NULL);
-	argv_array_pushv(&cp.args, argv);
-	argv_array_push(&cp.args, ref_stash);
-	argv_array_push(&cp.args, "--");
+	strvec_pushl(&cp.args, "log", "--format=%gd: %gs", "-g",
+		     "--first-parent", "-m", NULL);
+	strvec_pushv(&cp.args, argv);
+	strvec_push(&cp.args, ref_stash);
+	strvec_push(&cp.args, "--");
 	return run_command(&cp);
 }
 
 static int show_stat = 1;
 static int show_patch;
+static int use_legacy_stash;
 
 static int git_stash_config(const char *var, const char *value, void *cb)
 {
@@ -707,7 +714,11 @@ static int git_stash_config(const char *var, const char *value, void *cb)
 		show_patch = git_config_bool(var, value);
 		return 0;
 	}
-	return git_default_config(var, value, cb);
+	if (!strcmp(var, "stash.usebuiltin")) {
+		use_legacy_stash = !git_config_bool(var, value);
+		return 0;
+	}
+	return git_diff_basic_config(var, value, cb);
 }
 
 static int show_stash(int argc, const char **argv, const char *prefix)
@@ -716,8 +727,8 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	int ret = 0;
 	struct stash_info info;
 	struct rev_info rev;
-	struct argv_array stash_args = ARGV_ARRAY_INIT;
-	struct argv_array revision_args = ARGV_ARRAY_INIT;
+	struct strvec stash_args = STRVEC_INIT;
+	struct strvec revision_args = STRVEC_INIT;
 	struct option options[] = {
 		OPT_END()
 	};
@@ -726,16 +737,16 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	git_config(git_diff_ui_config, NULL);
 	init_revisions(&rev, prefix);
 
-	argv_array_push(&revision_args, argv[0]);
+	strvec_push(&revision_args, argv[0]);
 	for (i = 1; i < argc; i++) {
 		if (argv[i][0] != '-')
-			argv_array_push(&stash_args, argv[i]);
+			strvec_push(&stash_args, argv[i]);
 		else
-			argv_array_push(&revision_args, argv[i]);
+			strvec_push(&revision_args, argv[i]);
 	}
 
-	ret = get_stash_info(&info, stash_args.argc, stash_args.argv);
-	argv_array_clear(&stash_args);
+	ret = get_stash_info(&info, stash_args.nr, stash_args.v);
+	strvec_clear(&stash_args);
 	if (ret)
 		return -1;
 
@@ -743,8 +754,7 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 	 * The config settings are applied only if there are not passed
 	 * any options.
 	 */
-	if (revision_args.argc == 1) {
-		git_config(git_stash_config, NULL);
+	if (revision_args.nr == 1) {
 		if (show_stat)
 			rev.diffopt.output_format = DIFF_FORMAT_DIFFSTAT;
 
@@ -757,7 +767,7 @@ static int show_stash(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	argc = setup_revisions(revision_args.argc, revision_args.argv, &rev, NULL);
+	argc = setup_revisions(revision_args.nr, revision_args.v, &rev, NULL);
 	if (argc > 1) {
 		free_stash_info(&info);
 		usage_with_options(git_stash_show_usage, options);
@@ -832,12 +842,12 @@ static int store_stash(int argc, const char **argv, const char *prefix)
 	return do_store_stash(&obj, stash_msg, quiet);
 }
 
-static void add_pathspecs(struct argv_array *args,
+static void add_pathspecs(struct strvec *args,
 			  const struct pathspec *ps) {
 	int i;
 
 	for (i = 0; i < ps->nr; i++)
-		argv_array_push(args, ps->items[i].original);
+		strvec_push(args, ps->items[i].original);
 }
 
 /*
@@ -851,33 +861,23 @@ static int get_untracked_files(const struct pathspec *ps, int include_untracked,
 			       struct strbuf *untracked_files)
 {
 	int i;
-	int max_len;
 	int found = 0;
-	char *seen;
 	struct dir_struct dir;
 
-	memset(&dir, 0, sizeof(dir));
+	dir_init(&dir);
 	if (include_untracked != INCLUDE_ALL_FILES)
 		setup_standard_excludes(&dir);
 
-	seen = xcalloc(ps->nr, 1);
-
-	max_len = fill_directory(&dir, the_repository->index, ps);
+	fill_directory(&dir, the_repository->index, ps);
 	for (i = 0; i < dir.nr; i++) {
 		struct dir_entry *ent = dir.entries[i];
-		if (dir_path_match(&the_index, ent, ps, max_len, seen)) {
-			found++;
-			strbuf_addstr(untracked_files, ent->name);
-			/* NUL-terminate: will be fed to update-index -z */
-			strbuf_addch(untracked_files, '\0');
-		}
-		free(ent);
+		found++;
+		strbuf_addstr(untracked_files, ent->name);
+		/* NUL-terminate: will be fed to update-index -z */
+		strbuf_addch(untracked_files, '\0');
 	}
 
-	free(seen);
-	free(dir.entries);
-	free(dir.ignored);
-	clear_directory(&dir);
+	dir_clear(&dir);
 	return found;
 }
 
@@ -957,9 +957,9 @@ static int save_untracked_files(struct stash_info *info, struct strbuf *msg,
 	struct index_state istate = { NULL };
 
 	cp_upd_index.git_cmd = 1;
-	argv_array_pushl(&cp_upd_index.args, "update-index", "-z", "--add",
-			 "--remove", "--stdin", NULL);
-	argv_array_pushf(&cp_upd_index.env_array, "GIT_INDEX_FILE=%s",
+	strvec_pushl(&cp_upd_index.args, "update-index", "-z", "--add",
+		     "--remove", "--stdin", NULL);
+	strvec_pushf(&cp_upd_index.env_array, "GIT_INDEX_FILE=%s",
 			 stash_index_path.buf);
 
 	strbuf_addf(&untracked_msg, "untracked files on %s\n", msg->buf);
@@ -993,32 +993,35 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,
 {
 	int ret = 0;
 	struct child_process cp_read_tree = CHILD_PROCESS_INIT;
-	struct child_process cp_add_i = CHILD_PROCESS_INIT;
 	struct child_process cp_diff_tree = CHILD_PROCESS_INIT;
 	struct index_state istate = { NULL };
+	char *old_index_env = NULL, *old_repo_index_file;
 
 	remove_path(stash_index_path.buf);
 
 	cp_read_tree.git_cmd = 1;
-	argv_array_pushl(&cp_read_tree.args, "read-tree", "HEAD", NULL);
-	argv_array_pushf(&cp_read_tree.env_array, "GIT_INDEX_FILE=%s",
-			 stash_index_path.buf);
+	strvec_pushl(&cp_read_tree.args, "read-tree", "HEAD", NULL);
+	strvec_pushf(&cp_read_tree.env_array, "GIT_INDEX_FILE=%s",
+		     stash_index_path.buf);
 	if (run_command(&cp_read_tree)) {
 		ret = -1;
 		goto done;
 	}
 
 	/* Find out what the user wants. */
-	cp_add_i.git_cmd = 1;
-	argv_array_pushl(&cp_add_i.args, "add--interactive", "--patch=stash",
-			 "--", NULL);
-	add_pathspecs(&cp_add_i.args, ps);
-	argv_array_pushf(&cp_add_i.env_array, "GIT_INDEX_FILE=%s",
-			 stash_index_path.buf);
-	if (run_command(&cp_add_i)) {
-		ret = -1;
-		goto done;
-	}
+	old_repo_index_file = the_repository->index_file;
+	the_repository->index_file = stash_index_path.buf;
+	old_index_env = xstrdup_or_null(getenv(INDEX_ENVIRONMENT));
+	setenv(INDEX_ENVIRONMENT, the_repository->index_file, 1);
+
+	ret = run_add_interactive(NULL, "--patch=stash", ps);
+
+	the_repository->index_file = old_repo_index_file;
+	if (old_index_env && *old_index_env)
+		setenv(INDEX_ENVIRONMENT, old_index_env, 1);
+	else
+		unsetenv(INDEX_ENVIRONMENT);
+	FREE_AND_NULL(old_index_env);
 
 	/* State of the working tree. */
 	if (write_index_as_tree(&info->w_tree, &istate, stash_index_path.buf, 0,
@@ -1028,8 +1031,8 @@ static int stash_patch(struct stash_info *info, const struct pathspec *ps,
 	}
 
 	cp_diff_tree.git_cmd = 1;
-	argv_array_pushl(&cp_diff_tree.args, "diff-tree", "-p", "HEAD",
-			 oid_to_hex(&info->w_tree), "--", NULL);
+	strvec_pushl(&cp_diff_tree.args, "diff-tree", "-p", "-U1", "HEAD",
+		     oid_to_hex(&info->w_tree), "--", NULL);
 	if (pipe_command(&cp_diff_tree, NULL, 0, out_patch, 0, NULL, 0)) {
 		ret = -1;
 		goto done;
@@ -1082,10 +1085,11 @@ static int stash_working_tree(struct stash_info *info, const struct pathspec *ps
 	}
 
 	cp_upd_index.git_cmd = 1;
-	argv_array_pushl(&cp_upd_index.args, "update-index", "-z", "--add",
-			 "--remove", "--stdin", NULL);
-	argv_array_pushf(&cp_upd_index.env_array, "GIT_INDEX_FILE=%s",
-			 stash_index_path.buf);
+	strvec_pushl(&cp_upd_index.args, "update-index",
+		     "--ignore-skip-worktree-entries",
+		     "-z", "--add", "--remove", "--stdin", NULL);
+	strvec_pushf(&cp_upd_index.env_array, "GIT_INDEX_FILE=%s",
+		     stash_index_path.buf);
 
 	if (pipe_command(&cp_upd_index, diff_output.buf, diff_output.len,
 			 NULL, 0, NULL, 0)) {
@@ -1129,7 +1133,10 @@ static int do_create_stash(const struct pathspec *ps, struct strbuf *stash_msg_b
 	prepare_fallback_ident("git stash", "git@stash");
 
 	read_cache_preload(NULL);
-	refresh_cache(REFRESH_QUIET);
+	if (refresh_and_write_cache(REFRESH_QUIET, 0, 0) < 0) {
+		ret = -1;
+		goto done;
+	}
 
 	if (get_oid("HEAD", &info->b_commit)) {
 		if (!quiet)
@@ -1290,7 +1297,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 		free(ps_matched);
 	}
 
-	if (refresh_cache(REFRESH_QUIET)) {
+	if (refresh_and_write_cache(REFRESH_QUIET, 0, 0)) {
 		ret = -1;
 		goto done;
 	}
@@ -1332,10 +1339,10 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 			struct child_process cp = CHILD_PROCESS_INIT;
 
 			cp.git_cmd = 1;
-			argv_array_pushl(&cp.args, "clean", "--force",
-					 "--quiet", "-d", NULL);
+			strvec_pushl(&cp.args, "clean", "--force",
+				     "--quiet", "-d", NULL);
 			if (include_untracked == INCLUDE_ALL_FILES)
-				argv_array_push(&cp.args, "-x");
+				strvec_push(&cp.args, "-x");
 			if (run_command(&cp)) {
 				ret = -1;
 				goto done;
@@ -1349,12 +1356,12 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 			struct strbuf out = STRBUF_INIT;
 
 			cp_add.git_cmd = 1;
-			argv_array_push(&cp_add.args, "add");
+			strvec_push(&cp_add.args, "add");
 			if (!include_untracked)
-				argv_array_push(&cp_add.args, "-u");
+				strvec_push(&cp_add.args, "-u");
 			if (include_untracked == INCLUDE_ALL_FILES)
-				argv_array_push(&cp_add.args, "--force");
-			argv_array_push(&cp_add.args, "--");
+				strvec_push(&cp_add.args, "--force");
+			strvec_push(&cp_add.args, "--");
 			add_pathspecs(&cp_add.args, ps);
 			if (run_command(&cp_add)) {
 				ret = -1;
@@ -1362,9 +1369,9 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 			}
 
 			cp_diff.git_cmd = 1;
-			argv_array_pushl(&cp_diff.args, "diff-index", "-p",
-					 "--cached", "--binary", "HEAD", "--",
-					 NULL);
+			strvec_pushl(&cp_diff.args, "diff-index", "-p",
+				     "--cached", "--binary", "HEAD", "--",
+				     NULL);
 			add_pathspecs(&cp_diff.args, ps);
 			if (pipe_command(&cp_diff, NULL, 0, &out, 0, NULL, 0)) {
 				ret = -1;
@@ -1372,8 +1379,8 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 			}
 
 			cp_apply.git_cmd = 1;
-			argv_array_pushl(&cp_apply.args, "apply", "--index",
-					 "-R", NULL);
+			strvec_pushl(&cp_apply.args, "apply", "--index",
+				     "-R", NULL);
 			if (pipe_command(&cp_apply, out.buf, out.len, NULL, 0,
 					 NULL, 0)) {
 				ret = -1;
@@ -1382,8 +1389,8 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 		} else {
 			struct child_process cp = CHILD_PROCESS_INIT;
 			cp.git_cmd = 1;
-			argv_array_pushl(&cp.args, "reset", "--hard", "-q",
-					 NULL);
+			strvec_pushl(&cp.args, "reset", "--hard", "-q",
+				     "--no-recurse-submodules", NULL);
 			if (run_command(&cp)) {
 				ret = -1;
 				goto done;
@@ -1394,10 +1401,10 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 			struct child_process cp = CHILD_PROCESS_INIT;
 
 			cp.git_cmd = 1;
-			argv_array_pushl(&cp.args, "checkout", "--no-overlay",
-					 oid_to_hex(&info.i_tree), "--", NULL);
+			strvec_pushl(&cp.args, "checkout", "--no-overlay",
+				     oid_to_hex(&info.i_tree), "--", NULL);
 			if (!ps->nr)
-				argv_array_push(&cp.args, ":/");
+				strvec_push(&cp.args, ":/");
 			else
 				add_pathspecs(&cp.args, ps);
 			if (run_command(&cp)) {
@@ -1410,7 +1417,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 		struct child_process cp = CHILD_PROCESS_INIT;
 
 		cp.git_cmd = 1;
-		argv_array_pushl(&cp.args, "apply", "-R", NULL);
+		strvec_pushl(&cp.args, "apply", "-R", NULL);
 
 		if (pipe_command(&cp, patch.buf, patch.len, NULL, 0, NULL, 0)) {
 			if (!quiet)
@@ -1424,7 +1431,7 @@ static int do_push_stash(const struct pathspec *ps, const char *stash_msg, int q
 			struct child_process cp = CHILD_PROCESS_INIT;
 
 			cp.git_cmd = 1;
-			argv_array_pushl(&cp.args, "reset", "-q", "--", NULL);
+			strvec_pushl(&cp.args, "reset", "-q", "--", NULL);
 			add_pathspecs(&cp.args, ps);
 			if (run_command(&cp)) {
 				ret = -1;
@@ -1439,13 +1446,17 @@ done:
 	return ret;
 }
 
-static int push_stash(int argc, const char **argv, const char *prefix)
+static int push_stash(int argc, const char **argv, const char *prefix,
+		      int push_assumed)
 {
+	int force_assume = 0;
 	int keep_index = -1;
 	int patch_mode = 0;
 	int include_untracked = 0;
 	int quiet = 0;
+	int pathspec_file_nul = 0;
 	const char *stash_msg = NULL;
+	const char *pathspec_from_file = NULL;
 	struct pathspec ps;
 	struct option options[] = {
 		OPT_BOOL('k', "keep-index", &keep_index,
@@ -1459,16 +1470,45 @@ static int push_stash(int argc, const char **argv, const char *prefix)
 			    N_("include ignore files"), 2),
 		OPT_STRING('m', "message", &stash_msg, N_("message"),
 			   N_("stash message")),
+		OPT_PATHSPEC_FROM_FILE(&pathspec_from_file),
+		OPT_PATHSPEC_FILE_NUL(&pathspec_file_nul),
 		OPT_END()
 	};
 
-	if (argc)
+	if (argc) {
+		force_assume = !strcmp(argv[0], "-p");
 		argc = parse_options(argc, argv, prefix, options,
 				     git_stash_push_usage,
-				     0);
+				     PARSE_OPT_KEEP_DASHDASH);
+	}
+
+	if (argc) {
+		if (!strcmp(argv[0], "--")) {
+			argc--;
+			argv++;
+		} else if (push_assumed && !force_assume) {
+			die("subcommand wasn't specified; 'push' can't be assumed due to unexpected token '%s'",
+			    argv[0]);
+		}
+	}
 
 	parse_pathspec(&ps, 0, PATHSPEC_PREFER_FULL | PATHSPEC_PREFIX_ORIGIN,
 		       prefix, argv);
+
+	if (pathspec_from_file) {
+		if (patch_mode)
+			die(_("--pathspec-from-file is incompatible with --patch"));
+
+		if (ps.nr)
+			die(_("--pathspec-from-file is incompatible with pathspec arguments"));
+
+		parse_pathspec_file(&ps, 0,
+				    PATHSPEC_PREFER_FULL | PATHSPEC_PREFIX_ORIGIN,
+				    prefix, pathspec_from_file, pathspec_file_nul);
+	} else if (pathspec_file_nul) {
+		die(_("--pathspec-file-nul requires --pathspec-from-file"));
+	}
+
 	return do_push_stash(&ps, stash_msg, quiet, keep_index, patch_mode,
 			     include_untracked);
 }
@@ -1513,55 +1553,22 @@ static int save_stash(int argc, const char **argv, const char *prefix)
 	return ret;
 }
 
-static int use_builtin_stash(void)
-{
-	struct child_process cp = CHILD_PROCESS_INIT;
-	struct strbuf out = STRBUF_INIT;
-	int ret, env = git_env_bool("GIT_TEST_STASH_USE_BUILTIN", -1);
-
-	if (env != -1)
-		return env;
-
-	argv_array_pushl(&cp.args,
-			 "config", "--bool", "stash.usebuiltin", NULL);
-	cp.git_cmd = 1;
-	if (capture_command(&cp, &out, 6)) {
-		strbuf_release(&out);
-		return 1;
-	}
-
-	strbuf_trim(&out);
-	ret = !strcmp("true", out.buf);
-	strbuf_release(&out);
-	return ret;
-}
-
 int cmd_stash(int argc, const char **argv, const char *prefix)
 {
-	int i = -1;
 	pid_t pid = getpid();
 	const char *index_file;
-	struct argv_array args = ARGV_ARRAY_INIT;
+	struct strvec args = STRVEC_INIT;
 
 	struct option options[] = {
 		OPT_END()
 	};
 
-	if (!use_builtin_stash()) {
-		const char *path = mkpath("%s/git-legacy-stash",
-					  git_exec_path());
-
-		if (sane_execvp(path, (char **)argv) < 0)
-			die_errno(_("could not exec %s"), path);
-		else
-			BUG("sane_execvp() returned???");
-	}
-
-	prefix = setup_git_directory();
-	trace_repo_setup(prefix);
-	setup_work_tree();
+	git_config(git_stash_config, NULL);
 
-	git_config(git_diff_basic_config, NULL);
+	if (use_legacy_stash ||
+	    !git_env_bool("GIT_TEST_STASH_USE_BUILTIN", -1))
+		warning(_("the stash.useBuiltin support has been removed!\n"
+			  "See its entry in 'git help config' for details."));
 
 	argc = parse_options(argc, argv, prefix, options, git_stash_usage,
 			     PARSE_OPT_KEEP_UNKNOWN | PARSE_OPT_KEEP_DASHDASH);
@@ -1571,7 +1578,7 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
 		    (uintmax_t)pid);
 
 	if (!argc)
-		return !!push_stash(0, NULL, prefix);
+		return !!push_stash(0, NULL, prefix, 0);
 	else if (!strcmp(argv[0], "apply"))
 		return !!apply_stash(argc, argv, prefix);
 	else if (!strcmp(argv[0], "clear"))
@@ -1591,45 +1598,15 @@ int cmd_stash(int argc, const char **argv, const char *prefix)
 	else if (!strcmp(argv[0], "create"))
 		return !!create_stash(argc, argv, prefix);
 	else if (!strcmp(argv[0], "push"))
-		return !!push_stash(argc, argv, prefix);
+		return !!push_stash(argc, argv, prefix, 0);
 	else if (!strcmp(argv[0], "save"))
 		return !!save_stash(argc, argv, prefix);
 	else if (*argv[0] != '-')
 		usage_msg_opt(xstrfmt(_("unknown subcommand: %s"), argv[0]),
 			      git_stash_usage, options);
 
-	if (strcmp(argv[0], "-p")) {
-		while (++i < argc && strcmp(argv[i], "--")) {
-			/*
-			 * `akpqu` is a string which contains all short options,
-			 * except `-m` which is verified separately.
-			 */
-			if ((strlen(argv[i]) == 2) && *argv[i] == '-' &&
-			    strchr("akpqu", argv[i][1]))
-				continue;
-
-			if (!strcmp(argv[i], "--all") ||
-			    !strcmp(argv[i], "--keep-index") ||
-			    !strcmp(argv[i], "--no-keep-index") ||
-			    !strcmp(argv[i], "--patch") ||
-			    !strcmp(argv[i], "--quiet") ||
-			    !strcmp(argv[i], "--include-untracked"))
-				continue;
-
-			/*
-			 * `-m` and `--message=` are verified separately because
-			 * they need to be immediately followed by a string
-			 * (i.e.`-m"foobar"` or `--message="foobar"`).
-			 */
-			if (starts_with(argv[i], "-m") ||
-			    starts_with(argv[i], "--message="))
-				continue;
-
-			usage_with_options(git_stash_usage, options);
-		}
-	}
-
-	argv_array_push(&args, "push");
-	argv_array_pushv(&args, argv);
-	return !!push_stash(args.argc, args.argv, prefix);
+	/* Assume 'stash push' */
+	strvec_push(&args, "push");
+	strvec_pushv(&args, argv);
+	return !!push_stash(args.nr, args.v, prefix, 1);
 }