rev-list: fix --reverse interaction with --parents

--reverse did not interact well with --parents, as the included test
case shows: in a history like

  A--B.
   \   \
    `C--M--D

the command

  git rev-list --reverse --parents --full-history HEAD

erroneously lists D as having no parents at all.  (Without --reverse,
it correctly lists M.)

This is caused by the machinery driving --reverse: it first grabs all
commits through the normal routines, then runs them through the same
routines again, effectively simplifying them twice.

Fix this by moving the --reverse one level up, into get_revision().
This way we can cleanly grab all commits via the normal calls, then
just pop them off the list one by one without interfering with
get_revision_internal().

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/revision.c b/revision.c
index 0aaa4c10b9692b39eb3dfb1cf0e45890d598550e..d797f05c93abebddee4ca599f72841231b1426aa 100644 (file)
--- a/revision.c
+++ b/revision.c
@@ -1786,26 +1786,6 @@ static struct commit *get_revision_internal(struct rev_info *revs)
                return c;
        }
 
-       if (revs->reverse) {
-               int limit = -1;
-
-               if (0 <= revs->max_count) {
-                       limit = revs->max_count;
-                       if (0 < revs->skip_count)
-                               limit += revs->skip_count;
-               }
-               l = NULL;
-               while ((c = get_revision_1(revs))) {
-                       commit_list_insert(c, &l);
-                       if ((0 < limit) && !--limit)
-                               break;
-               }
-               revs->commits = l;
-               revs->reverse = 0;
-               revs->max_count = -1;
-               c = NULL;
-       }
-
        /*
         * Now pick up what they want to give us
         */
@@ -1878,7 +1858,23 @@ static struct commit *get_revision_internal(struct rev_info *revs)
 
 struct commit *get_revision(struct rev_info *revs)
 {
-       struct commit *c = get_revision_internal(revs);
+       struct commit *c;
+       struct commit_list *reversed;
+
+       if (revs->reverse) {
+               reversed = NULL;
+               while ((c = get_revision_internal(revs))) {
+                       commit_list_insert(c, &reversed);
+               }
+               revs->commits = reversed;
+               revs->reverse = 0;
+               revs->reverse_output_stage = 1;
+       }
+
+       if (revs->reverse_output_stage)
+               return pop_commit(&revs->commits);
+
+       c = get_revision_internal(revs);
        if (c && revs->graph)
                graph_update(revs->graph, c);
        return c;

diff --git a/revision.h b/revision.h
index dfa06b52106da5ac3dfc65676ea5dd043c95d3cf..b818cea76bd31004888ff4c7eecaa798533c508f 100644 (file)
--- a/revision.h
+++ b/revision.h
@@ -53,6 +53,7 @@ struct rev_info {
                        rewrite_parents:1,
                        print_parents:1,
                        reverse:1,
+                       reverse_output_stage:1,
                        cherry_pick:1,
                        first_parent_only:1;
 

diff --git a/t/t6013-rev-list-reverse-parents.sh b/t/t6013-rev-list-reverse-parents.sh
new file mode 100755 (executable)
index 0000000..d294466
--- /dev/null
+++ b/t/t6013-rev-list-reverse-parents.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+
+test_description='--reverse combines with --parents'
+
+. ./test-lib.sh
+
+
+commit () {
+       test_tick &&
+       echo $1 > foo &&
+       git add foo &&
+       git commit -m "$1"
+}
+
+test_expect_success 'set up --reverse example' '
+       commit one &&
+       git tag root &&
+       commit two &&
+       git checkout -b side HEAD^ &&
+       commit three &&
+       git checkout master &&
+       git merge -s ours side &&
+       commit five
+       '
+
+test_expect_success '--reverse --parents --full-history combines correctly' '
+       git rev-list --parents --full-history master -- foo |
+               tac > expected &&
+       git rev-list --reverse --parents --full-history master -- foo \
+               > actual &&
+       test_cmp actual expected
+       '
+
+test_expect_success '--boundary does too' '
+       git rev-list --boundary --parents --full-history master ^root -- foo |
+               tac > expected &&
+       git rev-list --boundary --reverse --parents --full-history \
+               master ^root -- foo > actual &&
+       test_cmp actual expected
+       '
+
+test_done