merge-base --octopus: reduce the result from get_octopus_merge_bases()

Scripts that use "merge-base --octopus" could do the reducing
themselves, but most of them are expected to want to get the reduced
results without having to do any work themselves.

Tests are taken from a message by Василий Макаров
<einmalfel@gmail.com>

Signed-off-by: Junio C Hamano <gitster@pobox.com>
---

 We might want to vet the existing callers of the underlying
 get_octopus_merge_bases() and find out if _all_ of them are doing
 anything extra (like deduping) because the machinery can return
 duplicate results. And if that is the case, then we may want to
 move the dedupling down the callchain instead of having it here.

diff --git a/builtin/merge-base.c b/builtin/merge-base.c
index daa96c79092933ed13dfc67f26062b2c308eb80a..87f4dbccaeae39e7bd52e89f368357d58bc20037 100644 (file)
--- a/builtin/merge-base.c
+++ b/builtin/merge-base.c
@@ -73,7 +73,7 @@ static int handle_octopus(int count, const char **args, int show_all)
        for (i = count - 1; i >= 0; i--)
                commit_list_insert(get_commit_reference(args[i]), &revs);
 
-       result = get_octopus_merge_bases(revs);
+       result = reduce_heads(get_octopus_merge_bases(revs));
 
        if (!result)
                return 1;

diff --git a/t/t6010-merge-base.sh b/t/t6010-merge-base.sh
index f80bba871cb45a4afb098c96e7925b6361cf7f95..abb5728b34b5eaba80d62f0e7d2b2c872dad4118 100755 (executable)
--- a/t/t6010-merge-base.sh
+++ b/t/t6010-merge-base.sh
@@ -230,4 +230,43 @@ test_expect_success 'criss-cross merge-base for octopus-step' '
        test_cmp expected.sorted actual.sorted
 '
 
+test_expect_success 'merge-base --octopus --all for complex tree' '
+       # Best common ancestor for JE, JAA and JDD is JC
+       #             JE
+       #            / |
+       #           /  |
+       #          /   |
+       #  JAA    /    |
+       #   |\   /     |
+       #   | \  | JDD |
+       #   |  \ |/ |  |
+       #   |   JC JD  |
+       #   |    | /|  |
+       #   |    |/ |  |
+       #  JA    |  |  |
+       #   |\  /|  |  |
+       #   X JB |  X  X
+       #   \  \ | /   /
+       #    \__\|/___/
+       #        J
+       test_commit J &&
+       test_commit JB &&
+       git reset --hard J &&
+       test_commit JC &&
+       git reset --hard J &&
+       test_commit JTEMP1 &&
+       test_merge JA JB &&
+       test_merge JAA JC &&
+       git reset --hard J &&
+       test_commit JTEMP2 &&
+       test_merge JD JB &&
+       test_merge JDD JC &&
+       git reset --hard J &&
+       test_commit JTEMP3 &&
+       test_merge JE JC &&
+       git rev-parse JC >expected &&
+       git merge-base --all --octopus JAA JDD JE >actual &&
+       test_cmp expected actual
+'
+
 test_done