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>

1 files changed, 3 insertions, 10 deletions

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 */