git-remote-mediawiki: set 'basetimestamp' to let the wiki handle conflicts

We already have a check that no new revisions are on the wiki at the
beginning of the push, but this didn't handle concurrent accesses to the
wiki.

Signed-off-by: Matthieu Moy <Matthieu.Moy@imag.fr>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/contrib/mw-to-git/git-remote-mediawiki b/contrib/mw-to-git/git-remote-mediawiki
index 768b42dfe8767b66c836b55b09aeedabed64e102..9bb58ab65f4389ae36cf9ac28bdf9970c269c316 100755 (executable)
--- a/contrib/mw-to-git/git-remote-mediawiki
+++ b/contrib/mw-to-git/git-remote-mediawiki
@@ -287,6 +287,9 @@ sub get_last_local_revision {
        return $lastrevision_number;
 }
 
+# Remember the timestamp corresponding to a revision id.
+my %basetimestamps;
+
 sub get_last_remote_revision {
        mw_connect_maybe();
 
@@ -300,7 +303,7 @@ sub get_last_remote_revision {
                my $query = {
                        action => 'query',
                        prop => 'revisions',
-                       rvprop => 'ids',
+                       rvprop => 'ids|timestamp',
                        pageids => $id,
                };
 
@@ -308,6 +311,8 @@ sub get_last_remote_revision {
 
                my $lastrev = pop(@{$result->{query}->{pages}->{$id}->{revisions}});
 
+               $basetimestamps{$lastrev->{revid}} = $lastrev->{timestamp};
+
                $max_rev_num = ($lastrev->{revid} > $max_rev_num ? $lastrev->{revid} : $max_rev_num);
        }
 
@@ -649,18 +654,32 @@ sub mw_push_file {
                        action => 'edit',
                        summary => $summary,
                        title => $title,
+                       basetimestamp => $basetimestamps{$newrevid},
                        text => mediawiki_clean($file_content, $page_created),
                                  }, {
                                          skip_encoding => 1 # Helps with names with accentuated characters
-                                 }) || die 'Fatal: Error ' .
-                                 $mediawiki->{error}->{code} .
-                                 ' from mediwiki: ' . $mediawiki->{error}->{details};
+                                 });
+               if (!$result) {
+                       if ($mediawiki->{error}->{code} == 3) {
+                               # edit conflicts, considered as non-fast-forward
+                               print STDERR 'Warning: Error ' .
+                                   $mediawiki->{error}->{code} .
+                                   ' from mediwiki: ' . $mediawiki->{error}->{details} .
+                                   ".\n";
+                               return ($newrevid, "non-fast-forward");
+                       } else {
+                               # Other errors. Shouldn't happen => just die()
+                               die 'Fatal: Error ' .
+                                   $mediawiki->{error}->{code} .
+                                   ' from mediwiki: ' . $mediawiki->{error}->{details};
+                       }
+               }
                $newrevid = $result->{edit}->{newrevid};
                print STDERR "Pushed file: $new_sha1 - $title\n";
        } else {
                print STDERR "$complete_file_name not a mediawiki file (Not pushable on this version of git-remote-mediawiki).\n"
        }
-       return $newrevid;
+       return ($newrevid, "ok");
 }
 
 sub mw_push {
@@ -767,13 +786,25 @@ sub mw_push_revision {
                chomp($commit_msg);
                # Push every blob
                while (@diff_info_list) {
+                       my $status;
                        # git diff-tree -z gives an output like
                        # <metadata>\0<filename1>\0
                        # <metadata>\0<filename2>\0
                        # and we've split on \0.
                        my $info = shift(@diff_info_list);
                        my $file = shift(@diff_info_list);
-                       $mw_revision = mw_push_file($info, $file, $commit_msg, $mw_revision);
+                       ($mw_revision, $status) = mw_push_file($info, $file, $commit_msg, $mw_revision);
+                       if ($status eq "non-fast-forward") {
+                               # we may already have sent part of the
+                               # commit to MediaWiki, but it's too
+                               # late to cancel it. Stop the push in
+                               # the middle, but still give an
+                               # accurate error message.
+                               return error_non_fast_forward($remote);
+                       }
+                       if ($status ne "ok") {
+                               die("Unknown error from mw_push_file()");
+                       }
                }
                unless ($dumb_push) {
                        run_git("notes --ref=$remotename/mediawiki add -m \"mediawiki_revision: $mw_revision\" $sha1_commit");