grep: fix "--" rev/pathspec disambiguation

diff --git a/builtin/grep.c b/builtin/grep.c
index 461347adb07a3e504e7c0719cd3e39ed08cadd02..e83b33bdaa784320211fe8f1e17f2cbdccfe7f25 100644 (file)
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -1149,7 +1149,22 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 
        compile_grep_patterns(&opt);
 
-       /* Check revs and then paths */
+       /*
+        * We have to find "--" in a separate pass, because its presence
+        * influences how we will parse arguments that come before it.
+        */
+       for (i = 0; i < argc; i++) {
+               if (!strcmp(argv[i], "--")) {
+                       seen_dashdash = 1;
+                       break;
+               }
+       }
+
+       /*
+        * Resolve any rev arguments. If we have a dashdash, then everything up
+        * to it must resolve as a rev. If not, then we stop at the first
+        * non-rev and assume everything else is a path.
+        */
        for (i = 0; i < argc; i++) {
                const char *arg = argv[i];
                unsigned char sha1[20];
@@ -1158,13 +1173,14 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
 
                if (!strcmp(arg, "--")) {
                        i++;
-                       seen_dashdash = 1;
                        break;
                }
 
-               /* Stop at the first non-rev */
-               if (get_sha1_with_context(arg, 0, sha1, &oc))
+               if (get_sha1_with_context(arg, 0, sha1, &oc)) {
+                       if (seen_dashdash)
+                               die(_("unable to resolve revision: %s"), arg);
                        break;
+               }
 
                object = parse_object_or_die(sha1, arg);
                if (!seen_dashdash)
@@ -1172,7 +1188,10 @@ int cmd_grep(int argc, const char **argv, const char *prefix)
                add_object_array_with_path(object, arg, &list, oc.mode, oc.path);
        }
 
-       /* The rest are paths */
+       /*
+        * Anything left over is presumed to be a path. But in the non-dashdash
+        * "do what I mean" case, we verify and complain when that isn't true.
+        */
        if (!seen_dashdash) {
                int j;
                for (j = i; j < argc; j++)