fetch: fix duplicate remote parallel fetch bug

Fetching in parallel from a remote group with a duplicated remote results
in the following:

error: cannot lock ref '<ref>': is at <oid> but expected <oid>

This doesn't happen in serial since fetching from the same remote that
has already been fetched from is a noop. Therefore, remove any duplicated
remotes after remote groups are parsed.

Signed-off-by: Calvin Wan <calvinwan@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/builtin/fetch.c b/builtin/fetch.c
index 7378caf..1297862 100644 (file)
--- a/builtin/fetch.c
+++ b/builtin/fetch.c
@@ -2228,6 +2228,7 @@ int cmd_fetch(int argc, const char **argv, const char *prefix)
                        argv++;
                }
        }
+       string_list_remove_duplicates(&list, 0);
 
        if (negotiate_only) {
                struct oidset acked_commits = OIDSET_INIT;

diff --git a/t/t5506-remote-groups.sh b/t/t5506-remote-groups.sh
index 5bac03e..0e17617 100755 (executable)
--- a/t/t5506-remote-groups.sh
+++ b/t/t5506-remote-groups.sh
@@ -99,4 +99,13 @@ test_expect_success 'updating remote name updates that remote' '
        ! repo_fetched two
 '
 
+test_expect_success 'updating group in parallel with a duplicate remote does not fail (fetch)' '
+       mark fetch-group-duplicate &&
+       update_repo one &&
+       git config --add remotes.duplicate one &&
+       git config --add remotes.duplicate one &&
+       git -c fetch.parallel=2 remote update duplicate &&
+       repo_fetched one
+'
+
 test_done