sparse-checkout: use in-process update for disable subcommand

The 'git sparse-checkout disable' subcommand returns a user to a
full working directory. The old process for doing this required
updating the sparse-checkout file with the "/*" pattern and then
updating the working directory with core.sparseCheckout enabled.
Finally, the sparse-checkout file could be removed and the config
setting disabled.

However, it is valuable to keep a user's sparse-checkout file
intact so they can re-enable the sparse-checkout they previously
used with 'git sparse-checkout init'. This is now possible with
the in-process mechanism for updating the working directory.

Reported-by: Szeder Gábor <szeder.dev@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 12 insertions, 13 deletions

diff --git a/builtin/sparse-checkout.c b/builtin/sparse-checkout.c
index a5d32e4702..a11ea65599 100644
--- a/builtin/sparse-checkout.c
+++ b/builtin/sparse-checkout.c
@@ -412,24 +412,23 @@ static int sparse_checkout_set(int argc, const char **argv, const char *prefix)
 
 static int sparse_checkout_disable(int argc, const char **argv)
 {
-	char *sparse_filename;
-	FILE *fp;
+	static const char *empty_base = "";
+	struct pattern_list pl;
+	struct strbuf match_all = STRBUF_INIT;
 
-	if (set_config(MODE_ALL_PATTERNS))
-		die(_("failed to change config"));
+	memset(&pl, 0, sizeof(pl));
+	hashmap_init(&pl.recursive_hashmap, pl_hashmap_cmp, NULL, 0);
+	hashmap_init(&pl.parent_hashmap, pl_hashmap_cmp, NULL, 0);
+	pl.use_cone_patterns = 0;
+	core_apply_sparse_checkout = 1;
 
-	sparse_filename = get_sparse_checkout_filename();
-	fp = xfopen(sparse_filename, "w");
-	fprintf(fp, "/*\n");
-	fclose(fp);
+	strbuf_addstr(&match_all, "/*");
+	add_pattern(strbuf_detach(&match_all, NULL), empty_base, 0, &pl, 0);
 
-	core_apply_sparse_checkout = 1;
-	if (update_working_directory(NULL))
+	if (update_working_directory(&pl))
 		die(_("error while refreshing working directory"));
 
-	unlink(sparse_filename);
-	free(sparse_filename);
-
+	clear_pattern_list(&pl);
 	return set_config(MODE_NO_PATTERNS);
 }