format-patch: introduce "--ignore-if-in-upstream"

With this flag, format-patch will try very hard not to output patches which
are already in the upstream branch.

Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-log.c b/builtin-log.c
index 44d2d136f585a74e462556a4f756c7a297cadd51..4ee5891dfd63e24db811bbc5f32f87f0f6b233ad 100644 (file)
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -160,6 +160,71 @@ static void reopen_stdout(struct commit *commit, int nr, int keep_subject)
        freopen(filename, "w", stdout);
 }
 
+static void reset_all_objects_flags()
+{
+       int i;
+
+       for (i = 0; i < obj_allocs; i++)
+               if (objs[i])
+                       objs[i]->flags = 0;
+}
+
+static int get_patch_id(struct commit *commit, struct diff_options *options,
+               unsigned char *sha1)
+{
+       diff_tree_sha1(commit->parents->item->object.sha1, commit->object.sha1,
+                       "", options);
+       diffcore_std(options);
+       return diff_flush_patch_id(options, sha1);
+}
+
+static void get_patch_ids(struct rev_info *rev, struct diff_options *options)
+{
+       struct rev_info check_rev;
+       struct commit *commit;
+       struct object *o1, *o2;
+       unsigned flags1, flags2;
+       unsigned char sha1[20];
+
+       if (rev->pending.nr != 2)
+               die("Need exactly one range.");
+
+       o1 = rev->pending.objects[0].item;
+       flags1 = o1->flags;
+       o2 = rev->pending.objects[1].item;
+       flags2 = o2->flags;
+
+       if ((flags1 & UNINTERESTING) == (flags2 & UNINTERESTING))
+               die("Not a range.");
+
+       diff_setup(options);
+       options->recursive = 1;
+       if (diff_setup_done(options) < 0)
+               die("diff_setup_done failed");
+
+       /* given a range a..b get all patch ids for b..a */
+       init_revisions(&check_rev);
+       o1->flags ^= UNINTERESTING;
+       o2->flags ^= UNINTERESTING;
+       add_pending_object(&check_rev, o1, "o1");
+       add_pending_object(&check_rev, o2, "o2");
+       prepare_revision_walk(&check_rev);
+
+       while ((commit = get_revision(&check_rev)) != NULL) {
+               /* ignore merges */
+               if (commit->parents && commit->parents->next)
+                       continue;
+
+               if (!get_patch_id(commit, options, sha1))
+                       created_object(sha1, xcalloc(1, sizeof(struct object)));
+       }
+
+       /* reset for next revision walk */
+       reset_all_objects_flags();
+       o1->flags = flags1;
+       o2->flags = flags2;
+}
+
 int cmd_format_patch(int argc, const char **argv, char **envp)
 {
        struct commit *commit;
@@ -170,6 +235,8 @@ int cmd_format_patch(int argc, const char **argv, char **envp)
        int numbered = 0;
        int start_number = -1;
        int keep_subject = 0;
+       int ignore_if_in_upstream = 0;
+       struct diff_options patch_id_opts;
        char *add_signoff = NULL;
 
        init_revisions(&rev);
@@ -235,6 +302,8 @@ int cmd_format_patch(int argc, const char **argv, char **envp)
                        rev.mime_boundary = git_version_string;
                else if (!strncmp(argv[i], "--attach=", 9))
                        rev.mime_boundary = argv[i] + 9;
+               else if (!strcmp(argv[i], "--ignore-if-in-upstream"))
+                       ignore_if_in_upstream = 1;
                else
                        argv[j++] = argv[i];
        }
@@ -262,14 +331,25 @@ int cmd_format_patch(int argc, const char **argv, char **envp)
                add_head(&rev);
        }
 
+       if (ignore_if_in_upstream)
+               get_patch_ids(&rev, &patch_id_opts);
+
        if (!use_stdout)
                realstdout = fdopen(dup(1), "w");
 
        prepare_revision_walk(&rev);
        while ((commit = get_revision(&rev)) != NULL) {
+               unsigned char sha1[20];
+
                /* ignore merges */
                if (commit->parents && commit->parents->next)
                        continue;
+
+               if (ignore_if_in_upstream &&
+                               !get_patch_id(commit, &patch_id_opts, sha1) &&
+                               lookup_object(sha1))
+                       continue;
+
                nr++;
                list = realloc(list, nr * sizeof(list[0]));
                list[nr - 1] = commit;