Merge branch 'ow/no-dryrun-in-add-i'

"git add -i --dry-run" does not dry-run, which was surprising.  The
combination of options has taught to error out.

* ow/no-dryrun-in-add-i:
  add: die if both --dry-run and --interactive are given

builtin/add.c

@@ -484,6 +484,8 @@ int cmd_add(int argc, const char **argv, const char *prefix)
 	if (patch_interactive)
 		add_interactive = 1;
 	if (add_interactive) {
+		if (show_only)
+			die(_("--dry-run is incompatible with --interactive/--patch"));
 		if (pathspec_from_file)
 			die(_("--pathspec-from-file is incompatible with --interactive/--patch"));
 		exit(interactive_add(argv + 1, prefix, patch_interactive));

t/t3700-add.sh

@@ -349,6 +349,10 @@ test_expect_success 'git add --dry-run --ignore-missing of non-existing file out
 	test_cmp expect.err actual.err
 '
 
+test_expect_success 'git add --dry-run --interactive should fail' '
+	test_must_fail git add --dry-run --interactive
+'
+
 test_expect_success 'git add empty string should fail' '
 	test_must_fail git add ""
 '