unpack-trees: introduce preserve_ignored to unpack_trees_options

Currently, every caller of unpack_trees() that wants to ensure ignored
files are overwritten by default needs to:
   * allocate unpack_trees_options.dir
   * flip the DIR_SHOW_IGNORED flag in unpack_trees_options.dir->flags
   * call setup_standard_excludes
AND then after the call to unpack_trees() needs to
   * call dir_clear()
   * deallocate unpack_trees_options.dir
That's a fair amount of boilerplate, and every caller uses identical
code.  Make this easier by instead introducing a new boolean value where
the default value (0) does what we want so that new callers of
unpack_trees() automatically get the appropriate behavior.  And move all
the handling of unpack_trees_options.dir into unpack_trees() itself.

While preserve_ignored = 0 is the behavior we feel is the appropriate
default, we defer fixing commands to use the appropriate default until a
later commit.  So, this commit introduces several locations where we
manually set preserve_ignored=1.  This makes it clear where code paths
were previously preserving ignored files when they should not have been;
a future commit will flip these to instead use a value of 0 to get the
behavior we want.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

7 files changed, 17 insertions, 19 deletions

diff --git a/builtin/am.c b/builtin/am.c
index 72cb3cc070..567ecd882b 100644
--- a/builtin/am.c
+++ b/builtin/am.c
@@ -1919,6 +1919,9 @@ static int fast_forward_to(struct tree *head, struct tree *remote, int reset)
 	opts.update = 1;
 	opts.merge = 1;
 	opts.reset = reset;
+	if (!reset)
+		/* FIXME: Default should be to remove ignored files */
+		opts.preserve_ignored = 1;
 	opts.fn = twoway_merge;
 	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
index 5335435d61..5e7957dd06 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -648,6 +648,7 @@ static int reset_tree(struct tree *tree, const struct checkout_opts *o,
 	opts.skip_unmerged = !worktree;
 	opts.reset = 1;
 	opts.merge = 1;
+	opts.preserve_ignored = 0;
 	opts.fn = oneway_merge;
 	opts.verbose_update = o->show_progress;
 	opts.src_index = &the_index;
@@ -746,11 +747,7 @@ static int merge_working_tree(const struct checkout_opts *opts,
 				       new_branch_info->commit ?
 				       &new_branch_info->commit->object.oid :
 				       &new_branch_info->oid, NULL);
-		if (opts->overwrite_ignore) {
-			topts.dir = xcalloc(1, sizeof(*topts.dir));
-			topts.dir->flags |= DIR_SHOW_IGNORED;
-			setup_standard_excludes(topts.dir);
-		}
+		topts.preserve_ignored = !opts->overwrite_ignore;
 		tree = parse_tree_indirect(old_branch_info->commit ?
 					   &old_branch_info->commit->object.oid :
 					   the_hash_algo->empty_tree);
@@ -760,10 +757,6 @@ static int merge_working_tree(const struct checkout_opts *opts,
 		init_tree_desc(&trees[1], tree->buffer, tree->size);
 
 		ret = unpack_trees(2, trees, &topts);
-		if (topts.dir) {
-			dir_clear(topts.dir);
-			FREE_AND_NULL(topts.dir);
-		}
 		clear_unpack_trees_porcelain(&topts);
 		if (ret == -1) {
 			/*
diff --git a/builtin/clone.c b/builtin/clone.c
index b93bcd460e..2ff9e9ca74 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -803,6 +803,8 @@ static int checkout(int submodule_progress)
 	opts.update = 1;
 	opts.merge = 1;
 	opts.clone = 1;
+	/* FIXME: Default should be to remove ignored files */
+	opts.preserve_ignored = 1;
 	opts.fn = oneway_merge;
 	opts.verbose_update = (option_verbosity >= 0);
 	opts.src_index = &the_index;
diff --git a/builtin/merge.c b/builtin/merge.c
index d2c52b6e97..89c99cf28c 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -681,6 +681,8 @@ static int read_tree_trivial(struct object_id *common, struct object_id *head,
 	opts.verbose_update = 1;
 	opts.trivial_merges_only = 1;
 	opts.merge = 1;
+	/* FIXME: Default should be to remove ignored files */
+	opts.preserve_ignored = 1;
 	trees[nr_trees] = parse_tree_indirect(common);
 	if (!trees[nr_trees++])
 		return -1;
diff --git a/builtin/read-tree.c b/builtin/read-tree.c
index 73cb957a69..443d206eca 100644
--- a/builtin/read-tree.c
+++ b/builtin/read-tree.c
@@ -201,11 +201,9 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	if ((opts.update || opts.index_only) && !opts.merge)
 		die("%s is meaningless without -m, --reset, or --prefix",
 		    opts.update ? "-u" : "-i");
-	if (opts.update && !opts.reset) {
-		CALLOC_ARRAY(opts.dir, 1);
-		opts.dir->flags |= DIR_SHOW_IGNORED;
-		setup_standard_excludes(opts.dir);
-	}
+	if (opts.update && !opts.reset)
+		opts.preserve_ignored = 0;
+	/* otherwise, opts.preserve_ignored is irrelevant */
 	if (opts.merge && !opts.index_only)
 		setup_work_tree();
 
@@ -245,11 +243,6 @@ int cmd_read_tree(int argc, const char **argv, const char *cmd_prefix)
 	if (unpack_trees(nr_trees, t, &opts))
 		return 128;
 
-	if (opts.dir) {
-		dir_clear(opts.dir);
-		FREE_AND_NULL(opts.dir);
-	}
-
 	if (opts.debug_unpack || opts.dry_run)
 		return 0; /* do not write the index out */
 
diff --git a/builtin/reset.c b/builtin/reset.c
index 51c9e2f43f..7f38656f01 100644
--- a/builtin/reset.c
+++ b/builtin/reset.c
@@ -67,6 +67,8 @@ static int reset_index(const char *ref, const struct object_id *oid, int reset_t
 	case KEEP:
 	case MERGE:
 		opts.update = 1;
+		/* FIXME: Default should be to remove ignored files */
+		opts.preserve_ignored = 1;
 		break;
 	case HARD:
 		opts.update = 1;
diff --git a/builtin/stash.c b/builtin/stash.c
index 8f42360ca9..88287b890d 100644
--- a/builtin/stash.c
+++ b/builtin/stash.c
@@ -258,6 +258,9 @@ static int reset_tree(struct object_id *i_tree, int update, int reset)
 	opts.merge = 1;
 	opts.reset = reset;
 	opts.update = update;
+	if (update && !reset)
+		/* FIXME: Default should be to remove ignored files */
+		opts.preserve_ignored = 1;
 	opts.fn = oneway_merge;
 
 	if (unpack_trees(nr_trees, t, &opts))