safe_create_leading_directories: fix race that could give a false negative

diff --git a/builtin/grep.c b/builtin/grep.c
index 29adb0ac9399002b07942711863fa3b353926468..0654e0b0f693f9cdd4ba2d7f84c110f7ef8b11b4 100644 (file)
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -209,6 +209,7 @@ static void start_threads(struct grep_opt *opt)
                int err;
                struct grep_opt *o = grep_opt_dup(opt);
                o->output = strbuf_out;
+               o->debug = 0;
                compile_grep_patterns(o);
                err = pthread_create(&threads[i], NULL, run, o);
 
@@ -772,6 +773,9 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                           "indicate hit with exit status without output"),
                OPT_BOOLEAN(0, "all-match", &opt.all_match,
                        "show only matches from files that match all patterns"),
+               { OPTION_SET_INT, 0, "debug", &opt.debug, NULL,
+                 "show parse tree for grep expression",
+                 PARSE_OPT_NOARG | PARSE_OPT_HIDDEN, NULL, 1 },
                OPT_GROUP(""),
                { OPTION_STRING, 'O', "open-files-in-pager", &show_in_pager,
                        "pager", "show matching files in the pager",