builtin-grep: tighten argument parsing.

I mistyped

	git grep next -e '"^@"' '*.c'

and got many hits that contain "next" without complaint.
Obviously what I meant to say was:

	git grep -e '"^@"' next -- '*.c'

This tightens the argument parsing rule a bit:

 - All "grep" parameters should come first;

 - If there is no -e nor -f to specify pattern, the first non
   option string is the parameter;

 - After that, zero or more revs can follow.

 - An optional '--' can be present, and is skipped.

 - All the rest are pathspecs.  If '--' was not there, they must
   be paths that exist in the working tree.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-grep.c b/builtin-grep.c
index a762c48..26a3fc3 100644 (file)
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -494,20 +494,30 @@ static const char builtin_grep_usage[] =
 int cmd_grep(int argc, const char **argv, char **envp)
 {
        int hit = 0;
-       int no_more_flags = 0;
        int cached = 0;
+       int seen_dashdash = 0;
        struct grep_opt opt;
        struct object_list *list, **tail, *object_list = NULL;
        const char *prefix = setup_git_directory();
        const char **paths = NULL;
+       int i;
 
        memset(&opt, 0, sizeof(opt));
        opt.pattern_tail = &opt.pattern_list;
        opt.regflags = REG_NEWLINE;
 
        /*
-        * No point using rev_info, really.
+        * If there is no -- then the paths must exist in the working
+        * tree.  If there is no explicit pattern specified with -e or
+        * -f, we take the first unrecognized non option to be the
+        * pattern, but then what follows it must be zero or more
+        * valid refs up to the -- (if exists), and then existing
+        * paths.  If there is an explicit pattern, then the first
+        * unrecocnized non option is the beginning of the refs list
+        * that continues up to the -- (if exists), and then paths.
         */
+
+       tail = &object_list;
        while (1 < argc) {
                const char *arg = argv[1];
                argc--; argv++;
@@ -618,7 +628,7 @@ int cmd_grep(int argc, const char **argv, char **envp)
                                usage(builtin_grep_usage);
                        patterns = fopen(argv[1], "r");
                        if (!patterns)
-                               die("'%s': %s", strerror(errno));
+                               die("'%s': %s", argv[1], strerror(errno));
                        while (fgets(buf, sizeof(buf), patterns)) {
                                int len = strlen(buf);
                                if (buf[len-1] == '\n')
@@ -642,47 +652,61 @@ int cmd_grep(int argc, const char **argv, char **envp)
                        }
                        usage(builtin_grep_usage);
                }
-               if (!strcmp("--", arg)) {
-                       no_more_flags = 1;
-                       continue;
-               }
-               /* Either unrecognized option or a single pattern */
-               if (!no_more_flags && *arg == '-')
+               if (!strcmp("--", arg))
+                       break;
+               if (*arg == '-')
                        usage(builtin_grep_usage);
+
+               /* First unrecognized non-option token */
                if (!opt.pattern_list) {
                        add_pattern(&opt, arg, "command line", 0);
                        break;
                }
                else {
                        /* We are looking at the first path or rev;
-                        * it is found at argv[0] after leaving the
+                        * it is found at argv[1] after leaving the
                         * loop.
                         */
                        argc++; argv--;
                        break;
                }
        }
+
        if (!opt.pattern_list)
                die("no pattern given.");
        compile_patterns(&opt);
-       tail = &object_list;
-       while (1 < argc) {
-               struct object *object;
-               struct object_list *elem;
-               const char *arg = argv[1];
+
+       /* Check revs and then paths */
+       for (i = 1; i < argc; i++) {
+               const char *arg = argv[i];
                unsigned char sha1[20];
-               if (get_sha1(arg, sha1) < 0)
-                       break;
-               object = parse_object(sha1);
-               if (!object)
-                       die("bad object %s", arg);
-               elem = object_list_insert(object, tail);
-               elem->name = arg;
-               tail = &elem->next;
-               argc--; argv++;
+               /* Is it a rev? */
+               if (!get_sha1(arg, sha1)) {
+                       struct object *object = parse_object(sha1);
+                       struct object_list *elem;
+                       if (!object)
+                               die("bad object %s", arg);
+                       elem = object_list_insert(object, tail);
+                       elem->name = arg;
+                       tail = &elem->next;
+                       continue;
+               }
+               if (!strcmp(arg, "--")) {
+                       i++;
+                       seen_dashdash = 1;
+               }
+               break;
        }
-       if (1 < argc)
-               paths = get_pathspec(prefix, argv + 1);
+
+       /* The rest are paths */
+       if (!seen_dashdash) {
+               int j;
+               for (j = i; j < argc; i++)
+                       verify_filename(prefix, argv[j]);
+       }
+
+       if (i < argc)
+               paths = get_pathspec(prefix, argv + i);
        else if (prefix) {
                paths = xcalloc(2, sizeof(const char *));
                paths[0] = prefix;