[PATCH v2 2/6] Change unpack_trees' 'reset' flag into an enum

@@ -1918,8 +1918,14 @@ 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 = reset ? UNPACK_RESET_PROTECT_UNTRACKED : 0;
 	opts.fn = twoway_merge;
+	if (opts.reset) {
+		/* Allow ignored files in the way to 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);
 

@@ -1928,6 +1934,11 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
 		return -1;
 	}
 
+	if (opts.reset) {
+		dir_clear(opts.dir);
+		FREE_AND_NULL(opts.dir);
+	}
+
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))
 		die(_("unable to write new index file"));
 

@@ -641,23 +641,37 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 {
 	struct unpack_trees_options opts;
 	struct tree_desc tree_desc;
+	int unpack_trees_ret;
 
 	memset(&opts, 0, sizeof(opts));
 	opts.head_idx = -1;
 	opts.update = worktree;
 	opts.skip_unmerged = !worktree;
-	opts.reset = 1;
+	opts.reset = o->force ? UNPACK_RESET_OVERWRITE_UNTRACKED :
+				UNPACK_RESET_PROTECT_UNTRACKED;
 	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);
 	parse_tree(tree);
 	init_tree_desc(&tree_desc, tree->buffer, tree->size);
-	switch (unpack_trees(1, &tree_desc, &opts)) {
+	unpack_trees_ret = unpack_trees(1, &tree_desc, &opts);
+
+	if (o->overwrite_ignore) {
+		dir_clear(opts.dir);
+		FREE_AND_NULL(opts.dir);
+	}
+
+	switch (unpack_trees_ret) {
 	case -2:
 		*writeout_error = 1;
 		/*

@@ -174,6 +174,9 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	if (1 < opts.merge + opts.reset + prefix_set)
 		die("Which one? -m, --reset, or --prefix?");
 
+	if (opts.reset)
+		opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
+
 	/*
 	 * NEEDSWORK
 	 *

@@ -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 +71,20 @@ static int reset_index(const char *ref, const struct object_id *oid, int reset_t
 		break;
 	case HARD:
 		opts.update = 1;
-		/* fallthrough */
+		opts.reset = UNPACK_RESET_OVERWRITE_UNTRACKED;
+		break;
+	case MIXED:
+		opts.reset = UNPACK_RESET_PROTECT_UNTRACKED;
+		/* but opts.update=0, so working tree not updated */
+		break;
 	default:
-		opts.reset = 1;
+		BUG("invalid reset_type passed to reset_index");
+	}
+	if (opts.reset == UNPACK_RESET_PROTECT_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();

@@ -104,6 +116,10 @@ static int reset_index(const char *ref, const struct object_id *oid, int reset_t
 	ret = 0;
 
 out:
+	if (opts.reset == UNPACK_RESET_PROTECT_UNTRACKED) {
+		dir_clear(opts.dir);
+		FREE_AND_NULL(opts.dir);
+	}
 	for (i = 0; i < nr; i++)
 		free((void *)desc[i].buffer);
 	return ret;

@@ -237,6 +237,7 @@ static int reset_tree(struct object_id *i_tree, int update, int reset)
 	struct tree_desc t[MAX_UNPACK_TREES];
 	struct tree *tree;
 	struct lock_file lock_file = LOCK_INIT;
+	int unpack_trees_ret;
 
 	read_cache_preload(NULL);
 	if (refresh_cache(REFRESH_QUIET))

@@ -256,11 +257,23 @@ 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 = reset ? UNPACK_RESET_PROTECT_UNTRACKED : 0;
+	if (opts.reset) {
+		opts.dir = xcalloc(1, sizeof(*opts.dir));
+		opts.dir->flags |= DIR_SHOW_IGNORED;
+		setup_standard_excludes(opts.dir);
+	}
 	opts.update = update;
 	opts.fn = oneway_merge;
 
-	if (unpack_trees(nr_trees, t, &opts))
+	unpack_trees_ret = unpack_trees(nr_trees, t, &opts);
+
+	if (opts.reset) {
+		dir_clear(opts.dir);
+		FREE_AND_NULL(opts.dir);
+	}
+
+	if (unpack_trees_ret)
 		return -1;
 
 	if (write_locked_index(&the_index, &lock_file, COMMIT_LOCK))

@@ -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 = UNPACK_RESET_PROTECT_UNTRACKED;
+		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"));

@@ -131,6 +136,10 @@ reset_head_refs:
 			    oid_to_hex(oid), "1", NULL);
 
 leave_reset_head:
+	if (unpack_tree_opts.dir) {
+		dir_clear(unpack_tree_opts.dir);
+		FREE_AND_NULL(unpack_tree_opts.dir);
+	}
 	strbuf_release(&msg);
 	rollback_lock_file(&lock);
 	clear_unpack_trees_porcelain(&unpack_tree_opts);

@@ -92,7 +92,7 @@ test_setup_checkout_m () {
 	)
 }
 
-test_expect_failure 'checkout -m does not nuke untracked file' '
+test_expect_success 'checkout -m does not nuke untracked file' '
 	test_setup_checkout_m &&
 	(
 		cd checkout &&

@@ -138,7 +138,7 @@ test_setup_sequencing () {
 	)
 }
 
-test_expect_failure 'git rebase --abort and untracked files' '
+test_expect_success 'git rebase --abort and untracked files' '
 	test_setup_sequencing rebase_abort_and_untracked &&
 	(
 		cd sequencing_rebase_abort_and_untracked &&

@@ -155,7 +155,7 @@ test_expect_failure 'git rebase --abort and untracked files' '
 	)
 '
 
-test_expect_failure 'git rebase fast forwarding and untracked files' '
+test_expect_success 'git rebase fast forwarding and untracked files' '
 	test_setup_sequencing rebase_fast_forward_and_untracked &&
 	(
 		cd sequencing_rebase_fast_forward_and_untracked &&

@@ -1693,6 +1693,9 @@ int unpack_trees(unsigned len, struct tree_desc *t, struct unpack_trees_options
 	struct pattern_list pl;
 	int free_pattern_list = 0;
 
+	if (o->reset == UNPACK_RESET_INVALID)
+		BUG("o->reset had a value of 1; should be UNPACK_TREES_*_UNTRACKED");
+
 	if (len > MAX_UNPACK_TREES)
 		die("unpack_trees takes at most %d trees", MAX_UNPACK_TREES);
 

@@ -2218,7 +2221,8 @@ static int verify_absent_1(const struct cache_entry *ce,
 	int len;
 	struct stat st;
 
-	if (o->index_only || o->reset || !o->update)
+	if (o->index_only || !o->update ||
+	    o->reset == UNPACK_RESET_OVERWRITE_UNTRACKED)
 		return 0;
 
 	len = check_leading_path(ce->name, ce_namelen(ce), 0);

@@ -45,9 +45,15 @@ void setup_unpack_trees_porcelain(struct unpack_trees_options *opts,
  */
 void clear_unpack_trees_porcelain(struct unpack_trees_options *opts);
 
+enum unpack_trees_reset_type {
+	UNPACK_RESET_NONE = 0,    /* traditional "false" value; still valid */
+	UNPACK_RESET_INVALID = 1, /* "true" no longer valid; use below values */
+	UNPACK_RESET_PROTECT_UNTRACKED,
+	UNPACK_RESET_OVERWRITE_UNTRACKED
+};
+
 struct unpack_trees_options {
-	unsigned int reset,
-		     merge,
+	unsigned int merge,
 		     update,
 		     clone,
 		     index_only,

@@ -64,6 +70,7 @@ struct unpack_trees_options {
 		     exiting_early,
 		     show_all_errors,
 		     dry_run;
+	enum unpack_trees_reset_type reset;
 	const char *prefix;
 	int cache_bottom;
 	struct dir_struct *dir;