add: update --chmod to skip sparse paths

We added checks for path_in_sparse_checkout() to portions of 'git add'
that add warnings and prevent staging a modification, but we skipped the
--chmod mode. Update chmod_pathspec() to ignore cache entries whose path
is outside of the sparse-checkout cone (unless --sparse is provided).
Add a test in t3705.

Signed-off-by: Derrick Stolee <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: derrickstolee

builtin/add.c

@@ -47,7 +47,9 @@ static int chmod_pathspec(struct pathspec *pathspec, char flip, int show_only)
 		struct cache_entry *ce = active_cache[i];
 		int err;
 
-		if (!include_sparse && ce_skip_worktree(ce))
+		if (!include_sparse &&
+		    (ce_skip_worktree(ce) ||
+		     !path_in_sparse_checkout(ce->name, &the_index)))
 			continue;
 
 		if (pathspec && !ce_path_match(&the_index, ce, pathspec, NULL))

t/t3705-add-sparse-checkout.sh

@@ -169,11 +169,19 @@ test_expect_success 'git add fails outside of sparse-checkout definition' '
 	test_must_fail git add sparse_entry &&
 	test_sparse_entry_unstaged &&
 
+	test_must_fail git add --chmod=+x sparse_entry &&
+	test_sparse_entry_unstaged &&
+
 	# Avoid munging CRLFs to avoid an error message
 	git -c core.autocrlf=input add --sparse sparse_entry 2>stderr &&
 	test_must_be_empty stderr &&
 	test-tool read-cache --table >actual &&
-	grep "^100644 blob.*sparse_entry\$" actual
+	grep "^100644 blob.*sparse_entry\$" actual &&
+
+	git add --sparse --chmod=+x sparse_entry 2>stderr &&
+	test_must_be_empty stderr &&
+	test-tool read-cache --table >actual &&
+	grep "^100755 blob.*sparse_entry\$" actual
 '
 
 test_expect_success 'add obeys advice.updateSparsePath' '