Merge branch 'jc/xsha1-2' into next

* jc/xsha1-2:
  Extended SHA1 -- "rev^@" syntax to mean "all parents"

diff --combined revision.c
index 3545df6,d1f85a8..846c9ec
--- 1/revision.c
--- 2/revision.c
+++ b/revision.c
@@@ -477,6 -477,36 +477,36 @@@ static void handle_all(struct rev_info 
        for_each_ref(handle_one_ref);
  }
  
+ static int add_parents_only(struct rev_info *revs, const char *arg, int flags)
+ {
+       unsigned char sha1[20];
+       struct object *it;
+       struct commit *commit;
+       struct commit_list *parents;
+ 
+       if (*arg == '^') {
+               flags ^= UNINTERESTING;
+               arg++;
+       }
+       if (get_sha1(arg, sha1))
+               return 0;
+       while (1) {
+               it = get_reference(revs, arg, sha1, 0);
+               if (strcmp(it->type, tag_type))
+                       break;
+               memcpy(sha1, ((struct tag*)it)->tagged->sha1, 20);
+       }
+       if (strcmp(it->type, commit_type))
+               return 0;
+       commit = (struct commit *)it;
+       for (parents = commit->parents; parents; parents = parents->next) {
+               it = &parents->item->object;
+               it->flags |= flags;
+               add_pending_object(revs, it, arg);
+       }
+       return 1;
+ }
+ 
  void init_revisions(struct rev_info *revs)
  {
        memset(revs, 0, sizeof(*revs));
@@@ -664,7 -694,6 +694,7 @@@ int setup_revisions(int argc, const cha
                        }
                        if (!strcmp(arg, "-c")) {
                                revs->diff = 1;
 +                              revs->dense_combined_merges = 0;
                                revs->combine_merges = 1;
                                continue;
                        }
@@@ -741,17 -770,19 +771,24 @@@
                                include = get_reference(revs, next, sha1, flags);
                                if (!exclude || !include)
                                        die("Invalid revision range %s..%s", arg, next);
 +
 +                              if (!seen_dashdash) {
 +                                      *dotdot = '.';
 +                                      verify_non_filename(revs->prefix, arg);
 +                              }
                                add_pending_object(revs, exclude, this);
                                add_pending_object(revs, include, next);
                                continue;
                        }
                        *dotdot = '.';
                }
+               dotdot = strstr(arg, "^@");
+               if (dotdot && !dotdot[2]) {
+                       *dotdot = 0;
+                       if (add_parents_only(revs, arg, flags))
+                               continue;
+                       *dotdot = '^';
+               }
                local_flags = 0;
                if (*arg == '^') {
                        local_flags = UNINTERESTING;
@@@ -763,20 -794,13 +800,20 @@@
                        if (seen_dashdash || local_flags)
                                die("bad revision '%s'", arg);
  
 -                      /* If we didn't have a "--", all filenames must exist */
 +                      /* If we didn't have a "--":
 +                       * (1) all filenames must exist;
 +                       * (2) all rev-args must not be interpretable
 +                       *     as a valid filename.
 +                       * but the latter we have checked in the main loop.
 +                       */
                        for (j = i; j < argc; j++)
                                verify_filename(revs->prefix, argv[j]);
  
                        revs->prune_data = get_pathspec(revs->prefix, argv + i);
                        break;
                }
 +              if (!seen_dashdash)
 +                      verify_non_filename(revs->prefix, arg);
                object = get_reference(revs, arg, sha1, flags ^ local_flags);
                add_pending_object(revs, object, arg);
        }