Merge branch 'en/removing-untracked-fixes' into seen

gitster · gitster · commit 010045485985 · 2021-09-22T14:15:36.000-07:00
Various fixes in code paths that move untracked files away to make room.

* en/removing-untracked-fixes:
  Documentation: call out commands that nuke untracked files/directories
  Comment important codepaths regarding nuking untracked files/dirs
  unpack-trees: avoid nuking untracked dir in way of locally deleted file
  unpack-trees: avoid nuking untracked dir in way of unmerged file
  Split unpack_trees 'reset' flag into two for untracked handling
  t2500: add various tests for nuking untracked files
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
@@ -118,8 +118,9 @@ OPTIONS
 -f::
 --force::
 	When switching branches, proceed even if the index or the
-	working tree differs from `HEAD`.  This is used to throw away
-	local changes.
+	working tree differs from `HEAD`, and even if there are untracked
+	files in the way.  This is used to throw away local changes and
+	any untracked files or directories that are in the way.
 +
 When checking out paths from the index, do not fail upon unmerged
 entries; instead, unmerged entries are ignored.
diff --git a/Documentation/git-read-tree.txt b/Documentation/git-read-tree.txt
@@ -39,8 +39,9 @@ OPTIONS
 
 --reset::
 	Same as -m, except that unmerged entries are discarded instead
-	of failing. When used with `-u`, updates leading to loss of
-	working tree changes will not abort the operation.
+	of failing.  When used with `-u`, updates leading to loss of
+	working tree changes or untracked files or directories will not
+	abort the operation.
 
 -u::
 	After a successful merge, update the files in the work
diff --git a/Documentation/git-reset.txt b/Documentation/git-reset.txt
@@ -69,7 +69,8 @@ linkgit:git-add[1]).
 
 --hard::
 	Resets the index and working tree. Any changes to tracked files in the
-	working tree since `<commit>` are discarded.
+	working tree since `<commit>` are discarded.  Any untracked files or
+	directories in the way of writing any tracked files are simply deleted.
 
 --merge::
 	Resets the index and updates the files in the working tree that are
diff --git a/builtin/am.c b/builtin/am.c
@@ -1917,8 +1917,12 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
 	opts.dst_index = &the_index;
 	opts.update = 1;
 	opts.merge = 1;
-	opts.reset = reset;
+	opts.reset_keep_untracked = reset;
 	opts.fn = twoway_merge;
+	/* Setup opts.dir so that ignored files in the way get overwritten */
+	opts.dir = xcalloc(1, sizeof(*opts.dir));
+	opts.dir->flags |= DIR_SHOW_IGNORED;
+	setup_standard_excludes(opts.dir);
 	init_tree_desc(&t[0], head->buffer, head->size);
 	init_tree_desc(&t[1], remote->buffer, remote->size);
 
diff --git a/builtin/checkout.c b/builtin/checkout.c
@@ -646,12 +646,20 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 	opts.head_idx = -1;
 	opts.update = worktree;
 	opts.skip_unmerged = !worktree;
-	opts.reset = 1;
+	if (o->force)
+		opts.reset_nuke_untracked = 1;
+	else
+		opts.reset_keep_untracked = 1;
 	opts.merge = 1;
 	opts.fn = oneway_merge;
 	opts.verbose_update = o->show_progress;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
+	if (o->overwrite_ignore) {
+		opts.dir = xcalloc(1, sizeof(*opts.dir));
+		opts.dir->flags |= DIR_SHOW_IGNORED;
+		setup_standard_excludes(opts.dir);
+	}
 	init_checkout_metadata(&opts.meta, info->refname,
 			       info->commit ? &info->commit->object.oid : null_oid(),
 			       NULL);
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
@@ -133,7 +133,7 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 			 N_("3-way merge if no file level merging required")),
 		OPT_BOOL(0, "aggressive", &opts.aggressive,
 			 N_("3-way merge in presence of adds and removes")),
-		OPT_BOOL(0, "reset", &opts.reset,
+		OPT_BOOL(0, "reset", &opts.reset_keep_untracked,
 			 N_("same as -m, but discard unmerged entries")),
 		{ OPTION_STRING, 0, "prefix", &opts.prefix, N_("<subdirectory>/"),
 		  N_("read the tree into the index under <subdirectory>/"),
@@ -162,6 +162,11 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	opts.head_idx = -1;
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
+	if (opts.reset_keep_untracked) {
+		opts.dir = xcalloc(1, sizeof(*opts.dir));
+		opts.dir->flags |= DIR_SHOW_IGNORED;
+		setup_standard_excludes(opts.dir);
+	}
 
 	git_config(git_read_tree_config, NULL);
 
@@ -171,7 +176,7 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	hold_locked_index(&lock_file, LOCK_DIE_ON_ERROR);
 
 	prefix_set = opts.prefix ? 1 : 0;
-	if (1 < opts.merge + opts.reset + prefix_set)
+	if (1 < opts.merge + opts.reset_keep_untracked + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
 
 	/*
@@ -183,7 +188,7 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	 * mode.
 	 */
 
-	if (opts.reset || opts.merge || opts.prefix) {
+	if (opts.reset_keep_untracked || opts.merge || opts.prefix) {
 		if (read_cache_unmerged() && (opts.prefix || opts.merge))
 			die(_("You need to resolve your current index first"));
 		stage = opts.merge = 1;
diff --git a/builtin/reset.c b/builtin/reset.c
@@ -10,6 +10,7 @@
 #define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
+#include "dir.h"
 #include "lockfile.h"
 #include "tag.h"
 #include "object.h"
@@ -70,9 +71,19 @@ static int reset_index(const char *ref, const struct object_id *oid, int reset_t
 		break;
 	case HARD:
 		opts.update = 1;
-		/* fallthrough */
+		opts.reset_nuke_untracked = 1;
+		break;
+	case MIXED:
+		opts.reset_keep_untracked = 1; /* but opts.update=0, so untracked left alone */
+		break;
 	default:
-		opts.reset = 1;
+		BUG("invalid reset_type passed to reset_index");
+	}
+	if (opts.reset_keep_untracked) {
+		/* Setup opts.dir so we can overwrite ignored files */
+		opts.dir = xcalloc(1, sizeof(*opts.dir));
+		opts.dir->flags |= DIR_SHOW_IGNORED;
+		setup_standard_excludes(opts.dir);
 	}
 
 	read_cache_unmerged();
diff --git a/builtin/stash.c b/builtin/stash.c
@@ -256,7 +256,7 @@ static int reset_tree(struct object_id *i_tree, int update, int reset)
 	opts.src_index = &the_index;
 	opts.dst_index = &the_index;
 	opts.merge = 1;
-	opts.reset = reset;
+	opts.reset_keep_untracked = reset;
 	opts.update = update;
 	opts.fn = oneway_merge;
 
@@ -1533,6 +1533,7 @@ 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;
+			/* BUG: this nukes untracked files in the way */
 			strvec_pushl(&cp.args, "reset", "--hard", "-q",
 				     "--no-recurse-submodules", NULL);
 			if (run_command(&cp)) {
diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
@@ -3098,6 +3098,10 @@ static int add_submodule(const struct add_data *add_data)
 		prepare_submodule_repo_env(&cp.env_array);
 		cp.git_cmd = 1;
 		cp.dir = add_data->sm_path;
+		/*
+		 * NOTE: we only get here if add_data->force is true, so
+		 * passing --force to checkout is reasonable.
+		 */
 		strvec_pushl(&cp.args, "checkout", "-f", "-q", NULL);
 
 		if (add_data->branch) {
diff --git a/builtin/worktree.c b/builtin/worktree.c
@@ -356,6 +356,11 @@ static int add_worktree(const char *path, const char *refname,
 	if (opts->checkout) {
 		cp.argv = NULL;
 		strvec_clear(&cp.args);
+		/*
+		 * NOTE: reset --hard is okay here, because 'worktree add'
+		 * refuses to work in an extant non-empty directory, so there
+		 * is no risk of deleting untracked files.
+		 */
 		strvec_pushl(&cp.args, "reset", "--hard", "--no-recurse-submodules", NULL);
 		if (opts->quiet)
 			strvec_push(&cp.args, "--quiet");
diff --git a/contrib/rerere-train.sh b/contrib/rerere-train.sh
@@ -91,7 +91,7 @@ do
 		git checkout -q $commit -- .
 		git rerere
 	fi
-	git reset -q --hard
+	git reset -q --hard  # Might nuke untracked files...
 done
 
 if test -z "$branch"
diff --git a/reset.c b/reset.c
@@ -1,5 +1,6 @@
 #include "git-compat-util.h"
 #include "cache-tree.h"
+#include "dir.h"
 #include "lockfile.h"
 #include "refs.h"
 #include "reset.h"
@@ -57,8 +58,12 @@ int reset_head(struct repository *r, struct object_id *oid, const char *action,
 	unpack_tree_opts.update = 1;
 	unpack_tree_opts.merge = 1;
 	init_checkout_metadata(&unpack_tree_opts.meta, switch_to_branch, oid, NULL);
-	if (!detach_head)
-		unpack_tree_opts.reset = 1;
+	if (!detach_head) {
+		unpack_tree_opts.reset_keep_untracked = 1;
+		unpack_tree_opts.dir = xcalloc(1, sizeof(*unpack_tree_opts.dir));
+		unpack_tree_opts.dir->flags |= DIR_SHOW_IGNORED;
+		setup_standard_excludes(unpack_tree_opts.dir);
+	}
 
 	if (repo_read_index_unmerged(r) < 0) {
 		ret = error(_("could not read index"));
diff --git a/submodule.c b/submodule.c
@@ -1908,6 +1908,7 @@ static void submodule_reset_index(const char *path)
 
 	strvec_pushf(&cp.args, "--super-prefix=%s%s/",
 		     get_super_prefix_or_empty(), path);
+	/* TODO: determine if this might overwright untracked files */
 	strvec_pushl(&cp.args, "read-tree", "-u", "--reset", NULL);
 
 	strvec_push(&cp.args, empty_tree_oid_hex());
diff --git a/t/t1013-read-tree-submodule.sh b/t/t1013-read-tree-submodule.sh
@@ -10,10 +10,10 @@ KNOWN_FAILURE_SUBMODULE_OVERWRITE_IGNORED_UNTRACKED=1
 
 test_submodule_switch_recursing_with_args "read-tree -u -m"
 
-test_submodule_forced_switch_recursing_with_args "read-tree -u --reset"
+test_submodule_switch_recursing_with_args "read-tree -u --reset"
 
 test_submodule_switch "read-tree -u -m"
 
-test_submodule_forced_switch "read-tree -u --reset"
+test_submodule_switch "read-tree -u --reset"
 
 test_done
diff --git a/t/t2500-untracked-overwriting.sh b/t/t2500-untracked-overwriting.sh
diff --git a/unpack-trees.c b/unpack-trees.c
diff --git a/unpack-trees.h b/unpack-trees.h
