checkout-index: add --ignore-skip-worktree-bits option

Update `checkout-index` to no longer refresh files that have the
`skip-worktree` bit set, exiting with an error if `skip-worktree` filenames
are directly provided to `checkout-index`. The newly-added
`--ignore-skip-worktree-bits` option provides a mechanism to replicate the
old behavior, checking out *all* files specified (even those with
`skip-worktree` enabled).

The ability to toggle whether files should be checked-out based on
`skip-worktree` already exists in `git checkout` and `git restore` (both of
which have an `--ignore-skip-worktree-bits` option). The change to, by
default, ignore `skip-worktree` files is especially helpful for
sparse-checkout; it prevents inadvertent creation of files outside the
sparse definition on disk and eliminates the need to expand a sparse index
when using the `--all` option.

Internal usage of `checkout-index` in `git stash` and `git filter-branch` do
not make explicit use of files with `skip-worktree` enabled, so
`--ignore-skip-worktree-bits` is not added to them.

Helped-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Victoria Dye <vdye@github.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/builtin/checkout-index.c b/builtin/checkout-index.c
index e21620d964..615a118e2f 100644
--- a/builtin/checkout-index.c
+++ b/builtin/checkout-index.c
@@ -7,6 +7,7 @@
 #define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "builtin.h"
 #include "config.h"
+#include "dir.h"
 #include "lockfile.h"
 #include "quote.h"
 #include "cache-tree.h"
@@ -17,6 +18,7 @@
 #define CHECKOUT_ALL 4
 static int nul_term_line;
 static int checkout_stage; /* default to checkout stage0 */
+static int ignore_skip_worktree; /* default to 0 */
 static int to_tempfile;
 static char topath[4][TEMPORARY_FILENAME_LENGTH + 1];
 
@@ -65,6 +67,7 @@ static int checkout_file(const char *name, const char *prefix)
 	int namelen = strlen(name);
 	int pos = cache_name_pos(name, namelen);
 	int has_same_name = 0;
+	int is_skipped = 1;
 	int did_checkout = 0;
 	int errs = 0;
 
@@ -78,6 +81,9 @@ static int checkout_file(const char *name, const char *prefix)
 			break;
 		has_same_name = 1;
 		pos++;
+		if (!ignore_skip_worktree && ce_skip_worktree(ce))
+			break;
+		is_skipped = 0;
 		if (ce_stage(ce) != checkout_stage
 		    && (CHECKOUT_ALL != checkout_stage || !ce_stage(ce)))
 			continue;
@@ -106,6 +112,9 @@ static int checkout_file(const char *name, const char *prefix)
 		fprintf(stderr, "git checkout-index: %s ", name);
 		if (!has_same_name)
 			fprintf(stderr, "is not in the cache");
+		else if (is_skipped)
+			fprintf(stderr, "has skip-worktree enabled; "
+					"use '--ignore-skip-worktree-bits' to checkout");
 		else if (checkout_stage)
 			fprintf(stderr, "does not exist at stage %d",
 				checkout_stage);
@@ -125,6 +134,8 @@ static int checkout_all(const char *prefix, int prefix_length)
 	ensure_full_index(&the_index);
 	for (i = 0; i < active_nr ; i++) {
 		struct cache_entry *ce = active_cache[i];
+		if (!ignore_skip_worktree && ce_skip_worktree(ce))
+			continue;
 		if (ce_stage(ce) != checkout_stage
 		    && (CHECKOUT_ALL != checkout_stage || !ce_stage(ce)))
 			continue;
@@ -185,6 +196,8 @@ int cmd_checkout_index(int argc, const char **argv, const char *prefix)
 	struct option builtin_checkout_index_options[] = {
 		OPT_BOOL('a', "all", &all,
 			N_("check out all files in the index")),
+		OPT_BOOL(0, "ignore-skip-worktree-bits", &ignore_skip_worktree,
+			N_("do not skip files with skip-worktree set")),
 		OPT__FORCE(&force, N_("force overwrite of existing files"), 0),
 		OPT__QUIET(&quiet,
 			N_("no warning for existing files and files not in index")),