contrib / mw-to-git / git-remote-mediawikion commit Merge branch 'jc/maint-pack-object-cycle' (cddec4f)
   1#! /usr/bin/perl
   2
   3# Copyright (C) 2011
   4#     Jérémie Nikaes <jeremie.nikaes@ensimag.imag.fr>
   5#     Arnaud Lacurie <arnaud.lacurie@ensimag.imag.fr>
   6#     Claire Fousse <claire.fousse@ensimag.imag.fr>
   7#     David Amouyal <david.amouyal@ensimag.imag.fr>
   8#     Matthieu Moy <matthieu.moy@grenoble-inp.fr>
   9# License: GPL v2 or later
  10
  11# Gateway between Git and MediaWiki.
  12#   https://github.com/Bibzball/Git-Mediawiki/wiki
  13#
  14# Known limitations:
  15#
  16# - Only wiki pages are managed, no support for [[File:...]]
  17#   attachments.
  18#
  19# - Poor performance in the best case: it takes forever to check
  20#   whether we're up-to-date (on fetch or push) or to fetch a few
  21#   revisions from a large wiki, because we use exclusively a
  22#   page-based synchronization. We could switch to a wiki-wide
  23#   synchronization when the synchronization involves few revisions
  24#   but the wiki is large.
  25#
  26# - Git renames could be turned into MediaWiki renames (see TODO
  27#   below)
  28#
  29# - login/password support requires the user to write the password
  30#   cleartext in a file (see TODO below).
  31#
  32# - No way to import "one page, and all pages included in it"
  33#
  34# - Multiple remote MediaWikis have not been very well tested.
  35
  36use strict;
  37use MediaWiki::API;
  38use DateTime::Format::ISO8601;
  39use encoding 'utf8';
  40
  41# use encoding 'utf8' doesn't change STDERROR
  42# but we're going to output UTF-8 filenames to STDERR
  43binmode STDERR, ":utf8";
  44
  45use URI::Escape;
  46use warnings;
  47
  48# Mediawiki filenames can contain forward slashes. This variable decides by which pattern they should be replaced
  49use constant SLASH_REPLACEMENT => "%2F";
  50
  51# It's not always possible to delete pages (may require some
  52# priviledges). Deleted pages are replaced with this content.
  53use constant DELETED_CONTENT => "[[Category:Deleted]]\n";
  54
  55# It's not possible to create empty pages. New empty files in Git are
  56# sent with this content instead.
  57use constant EMPTY_CONTENT => "<!-- empty page -->\n";
  58
  59# used to reflect file creation or deletion in diff.
  60use constant NULL_SHA1 => "0000000000000000000000000000000000000000";
  61
  62my $remotename = $ARGV[0];
  63my $url = $ARGV[1];
  64
  65# Accept both space-separated and multiple keys in config file.
  66# Spaces should be written as _ anyway because we'll use chomp.
  67my @tracked_pages = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".pages"));
  68chomp(@tracked_pages);
  69
  70# Just like @tracked_pages, but for MediaWiki categories.
  71my @tracked_categories = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".categories"));
  72chomp(@tracked_categories);
  73
  74my $wiki_login = run_git("config --get remote.". $remotename .".mwLogin");
  75# TODO: ideally, this should be able to read from keyboard, but we're
  76# inside a remote helper, so our stdin is connect to git, not to a
  77# terminal.
  78my $wiki_passwd = run_git("config --get remote.". $remotename .".mwPassword");
  79my $wiki_domain = run_git("config --get remote.". $remotename .".mwDomain");
  80chomp($wiki_login);
  81chomp($wiki_passwd);
  82chomp($wiki_domain);
  83
  84# Import only last revisions (both for clone and fetch)
  85my $shallow_import = run_git("config --get --bool remote.". $remotename .".shallow");
  86chomp($shallow_import);
  87$shallow_import = ($shallow_import eq "true");
  88
  89# Dumb push: don't update notes and mediawiki ref to reflect the last push.
  90#
  91# Configurable with mediawiki.dumbPush, or per-remote with
  92# remote.<remotename>.dumbPush.
  93#
  94# This means the user will have to re-import the just-pushed
  95# revisions. On the other hand, this means that the Git revisions
  96# corresponding to MediaWiki revisions are all imported from the wiki,
  97# regardless of whether they were initially created in Git or from the
  98# web interface, hence all users will get the same history (i.e. if
  99# the push from Git to MediaWiki loses some information, everybody
 100# will get the history with information lost). If the import is
 101# deterministic, this means everybody gets the same sha1 for each
 102# MediaWiki revision.
 103my $dumb_push = run_git("config --get --bool remote.$remotename.dumbPush");
 104unless ($dumb_push) {
 105        $dumb_push = run_git("config --get --bool mediawiki.dumbPush");
 106}
 107chomp($dumb_push);
 108$dumb_push = ($dumb_push eq "true");
 109
 110my $wiki_name = $url;
 111$wiki_name =~ s/[^\/]*:\/\///;
 112# If URL is like http://user:password@example.com/, we clearly don't
 113# want the password in $wiki_name. While we're there, also remove user
 114# and '@' sign, to avoid author like MWUser@HTTPUser@host.com
 115$wiki_name =~ s/^.*@//;
 116
 117# Commands parser
 118my $entry;
 119my @cmd;
 120while (<STDIN>) {
 121        chomp;
 122        @cmd = split(/ /);
 123        if (defined($cmd[0])) {
 124                # Line not blank
 125                if ($cmd[0] eq "capabilities") {
 126                        die("Too many arguments for capabilities") unless (!defined($cmd[1]));
 127                        mw_capabilities();
 128                } elsif ($cmd[0] eq "list") {
 129                        die("Too many arguments for list") unless (!defined($cmd[2]));
 130                        mw_list($cmd[1]);
 131                } elsif ($cmd[0] eq "import") {
 132                        die("Invalid arguments for import") unless ($cmd[1] ne "" && !defined($cmd[2]));
 133                        mw_import($cmd[1]);
 134                } elsif ($cmd[0] eq "option") {
 135                        die("Too many arguments for option") unless ($cmd[1] ne "" && $cmd[2] ne "" && !defined($cmd[3]));
 136                        mw_option($cmd[1],$cmd[2]);
 137                } elsif ($cmd[0] eq "push") {
 138                        mw_push($cmd[1]);
 139                } else {
 140                        print STDERR "Unknown command. Aborting...\n";
 141                        last;
 142                }
 143        } else {
 144                # blank line: we should terminate
 145                last;
 146        }
 147
 148        BEGIN { $| = 1 } # flush STDOUT, to make sure the previous
 149                         # command is fully processed.
 150}
 151
 152########################## Functions ##############################
 153
 154# MediaWiki API instance, created lazily.
 155my $mediawiki;
 156
 157sub mw_connect_maybe {
 158        if ($mediawiki) {
 159            return;
 160        }
 161        $mediawiki = MediaWiki::API->new;
 162        $mediawiki->{config}->{api_url} = "$url/api.php";
 163        if ($wiki_login) {
 164                if (!$mediawiki->login({
 165                        lgname => $wiki_login,
 166                        lgpassword => $wiki_passwd,
 167                        lgdomain => $wiki_domain,
 168                })) {
 169                        print STDERR "Failed to log in mediawiki user \"$wiki_login\" on $url\n";
 170                        print STDERR "(error " .
 171                            $mediawiki->{error}->{code} . ': ' .
 172                            $mediawiki->{error}->{details} . ")\n";
 173                        exit 1;
 174                } else {
 175                        print STDERR "Logged in with user \"$wiki_login\".\n";
 176                }
 177        }
 178}
 179
 180sub get_mw_first_pages {
 181        my $some_pages = shift;
 182        my @some_pages = @{$some_pages};
 183
 184        my $pages = shift;
 185
 186        # pattern 'page1|page2|...' required by the API
 187        my $titles = join('|', @some_pages);
 188
 189        my $mw_pages = $mediawiki->api({
 190                action => 'query',
 191                titles => $titles,
 192        });
 193        if (!defined($mw_pages)) {
 194                print STDERR "fatal: could not query the list of wiki pages.\n";
 195                print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 196                print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 197                exit 1;
 198        }
 199        while (my ($id, $page) = each(%{$mw_pages->{query}->{pages}})) {
 200                if ($id < 0) {
 201                        print STDERR "Warning: page $page->{title} not found on wiki\n";
 202                } else {
 203                        $pages->{$page->{title}} = $page;
 204                }
 205        }
 206}
 207
 208sub get_mw_pages {
 209        mw_connect_maybe();
 210
 211        my %pages; # hash on page titles to avoid duplicates
 212        my $user_defined;
 213        if (@tracked_pages) {
 214                $user_defined = 1;
 215                # The user provided a list of pages titles, but we
 216                # still need to query the API to get the page IDs.
 217
 218                my @some_pages = @tracked_pages;
 219                while (@some_pages) {
 220                        my $last = 50;
 221                        if ($#some_pages < $last) {
 222                                $last = $#some_pages;
 223                        }
 224                        my @slice = @some_pages[0..$last];
 225                        get_mw_first_pages(\@slice, \%pages);
 226                        @some_pages = @some_pages[51..$#some_pages];
 227                }
 228        }
 229        if (@tracked_categories) {
 230                $user_defined = 1;
 231                foreach my $category (@tracked_categories) {
 232                        if (index($category, ':') < 0) {
 233                                # Mediawiki requires the Category
 234                                # prefix, but let's not force the user
 235                                # to specify it.
 236                                $category = "Category:" . $category;
 237                        }
 238                        my $mw_pages = $mediawiki->list( {
 239                                action => 'query',
 240                                list => 'categorymembers',
 241                                cmtitle => $category,
 242                                cmlimit => 'max' } )
 243                            || die $mediawiki->{error}->{code} . ': ' . $mediawiki->{error}->{details};
 244                        foreach my $page (@{$mw_pages}) {
 245                                $pages{$page->{title}} = $page;
 246                        }
 247                }
 248        }
 249        if (!$user_defined) {
 250                # No user-provided list, get the list of pages from
 251                # the API.
 252                my $mw_pages = $mediawiki->list({
 253                        action => 'query',
 254                        list => 'allpages',
 255                        aplimit => 500,
 256                });
 257                if (!defined($mw_pages)) {
 258                        print STDERR "fatal: could not get the list of wiki pages.\n";
 259                        print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 260                        print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 261                        exit 1;
 262                }
 263                foreach my $page (@{$mw_pages}) {
 264                        $pages{$page->{title}} = $page;
 265                }
 266        }
 267        return values(%pages);
 268}
 269
 270sub run_git {
 271        open(my $git, "-|:encoding(UTF-8)", "git " . $_[0]);
 272        my $res = do { local $/; <$git> };
 273        close($git);
 274
 275        return $res;
 276}
 277
 278
 279sub get_last_local_revision {
 280        # Get note regarding last mediawiki revision
 281        my $note = run_git("notes --ref=$remotename/mediawiki show refs/mediawiki/$remotename/master 2>/dev/null");
 282        my @note_info = split(/ /, $note);
 283
 284        my $lastrevision_number;
 285        if (!(defined($note_info[0]) && $note_info[0] eq "mediawiki_revision:")) {
 286                print STDERR "No previous mediawiki revision found";
 287                $lastrevision_number = 0;
 288        } else {
 289                # Notes are formatted : mediawiki_revision: #number
 290                $lastrevision_number = $note_info[1];
 291                chomp($lastrevision_number);
 292                print STDERR "Last local mediawiki revision found is $lastrevision_number";
 293        }
 294        return $lastrevision_number;
 295}
 296
 297# Remember the timestamp corresponding to a revision id.
 298my %basetimestamps;
 299
 300sub get_last_remote_revision {
 301        mw_connect_maybe();
 302
 303        my @pages = get_mw_pages();
 304
 305        my $max_rev_num = 0;
 306
 307        foreach my $page (@pages) {
 308                my $id = $page->{pageid};
 309
 310                my $query = {
 311                        action => 'query',
 312                        prop => 'revisions',
 313                        rvprop => 'ids|timestamp',
 314                        pageids => $id,
 315                };
 316
 317                my $result = $mediawiki->api($query);
 318
 319                my $lastrev = pop(@{$result->{query}->{pages}->{$id}->{revisions}});
 320
 321                $basetimestamps{$lastrev->{revid}} = $lastrev->{timestamp};
 322
 323                $max_rev_num = ($lastrev->{revid} > $max_rev_num ? $lastrev->{revid} : $max_rev_num);
 324        }
 325
 326        print STDERR "Last remote revision found is $max_rev_num.\n";
 327        return $max_rev_num;
 328}
 329
 330# Clean content before sending it to MediaWiki
 331sub mediawiki_clean {
 332        my $string = shift;
 333        my $page_created = shift;
 334        # Mediawiki does not allow blank space at the end of a page and ends with a single \n.
 335        # This function right trims a string and adds a \n at the end to follow this rule
 336        $string =~ s/\s+$//;
 337        if ($string eq "" && $page_created) {
 338                # Creating empty pages is forbidden.
 339                $string = EMPTY_CONTENT;
 340        }
 341        return $string."\n";
 342}
 343
 344# Filter applied on MediaWiki data before adding them to Git
 345sub mediawiki_smudge {
 346        my $string = shift;
 347        if ($string eq EMPTY_CONTENT) {
 348                $string = "";
 349        }
 350        # This \n is important. This is due to mediawiki's way to handle end of files.
 351        return $string."\n";
 352}
 353
 354sub mediawiki_clean_filename {
 355        my $filename = shift;
 356        $filename =~ s/@{[SLASH_REPLACEMENT]}/\//g;
 357        # [, ], |, {, and } are forbidden by MediaWiki, even URL-encoded.
 358        # Do a variant of URL-encoding, i.e. looks like URL-encoding,
 359        # but with _ added to prevent MediaWiki from thinking this is
 360        # an actual special character.
 361        $filename =~ s/[\[\]\{\}\|]/sprintf("_%%_%x", ord($&))/ge;
 362        # If we use the uri escape before
 363        # we should unescape here, before anything
 364
 365        return $filename;
 366}
 367
 368sub mediawiki_smudge_filename {
 369        my $filename = shift;
 370        $filename =~ s/\//@{[SLASH_REPLACEMENT]}/g;
 371        $filename =~ s/ /_/g;
 372        # Decode forbidden characters encoded in mediawiki_clean_filename
 373        $filename =~ s/_%_([0-9a-fA-F][0-9a-fA-F])/sprintf("%c", hex($1))/ge;
 374        return $filename;
 375}
 376
 377sub literal_data {
 378        my ($content) = @_;
 379        print STDOUT "data ", bytes::length($content), "\n", $content;
 380}
 381
 382sub mw_capabilities {
 383        # Revisions are imported to the private namespace
 384        # refs/mediawiki/$remotename/ by the helper and fetched into
 385        # refs/remotes/$remotename later by fetch.
 386        print STDOUT "refspec refs/heads/*:refs/mediawiki/$remotename/*\n";
 387        print STDOUT "import\n";
 388        print STDOUT "list\n";
 389        print STDOUT "push\n";
 390        print STDOUT "\n";
 391}
 392
 393sub mw_list {
 394        # MediaWiki do not have branches, we consider one branch arbitrarily
 395        # called master, and HEAD pointing to it.
 396        print STDOUT "? refs/heads/master\n";
 397        print STDOUT "\@refs/heads/master HEAD\n";
 398        print STDOUT "\n";
 399}
 400
 401sub mw_option {
 402        print STDERR "remote-helper command 'option $_[0]' not yet implemented\n";
 403        print STDOUT "unsupported\n";
 404}
 405
 406sub fetch_mw_revisions_for_page {
 407        my $page = shift;
 408        my $id = shift;
 409        my $fetch_from = shift;
 410        my @page_revs = ();
 411        my $query = {
 412                action => 'query',
 413                prop => 'revisions',
 414                rvprop => 'ids',
 415                rvdir => 'newer',
 416                rvstartid => $fetch_from,
 417                rvlimit => 500,
 418                pageids => $id,
 419        };
 420
 421        my $revnum = 0;
 422        # Get 500 revisions at a time due to the mediawiki api limit
 423        while (1) {
 424                my $result = $mediawiki->api($query);
 425
 426                # Parse each of those 500 revisions
 427                foreach my $revision (@{$result->{query}->{pages}->{$id}->{revisions}}) {
 428                        my $page_rev_ids;
 429                        $page_rev_ids->{pageid} = $page->{pageid};
 430                        $page_rev_ids->{revid} = $revision->{revid};
 431                        push(@page_revs, $page_rev_ids);
 432                        $revnum++;
 433                }
 434                last unless $result->{'query-continue'};
 435                $query->{rvstartid} = $result->{'query-continue'}->{revisions}->{rvstartid};
 436        }
 437        if ($shallow_import && @page_revs) {
 438                print STDERR "  Found 1 revision (shallow import).\n";
 439                @page_revs = sort {$b->{revid} <=> $a->{revid}} (@page_revs);
 440                return $page_revs[0];
 441        }
 442        print STDERR "  Found ", $revnum, " revision(s).\n";
 443        return @page_revs;
 444}
 445
 446sub fetch_mw_revisions {
 447        my $pages = shift; my @pages = @{$pages};
 448        my $fetch_from = shift;
 449
 450        my @revisions = ();
 451        my $n = 1;
 452        foreach my $page (@pages) {
 453                my $id = $page->{pageid};
 454
 455                print STDERR "page $n/", scalar(@pages), ": ". $page->{title} ."\n";
 456                $n++;
 457                my @page_revs = fetch_mw_revisions_for_page($page, $id, $fetch_from);
 458                @revisions = (@page_revs, @revisions);
 459        }
 460
 461        return ($n, @revisions);
 462}
 463
 464sub import_file_revision {
 465        my $commit = shift;
 466        my %commit = %{$commit};
 467        my $full_import = shift;
 468        my $n = shift;
 469
 470        my $title = $commit{title};
 471        my $comment = $commit{comment};
 472        my $content = $commit{content};
 473        my $author = $commit{author};
 474        my $date = $commit{date};
 475
 476        print STDOUT "commit refs/mediawiki/$remotename/master\n";
 477        print STDOUT "mark :$n\n";
 478        print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 479        literal_data($comment);
 480
 481        # If it's not a clone, we need to know where to start from
 482        if (!$full_import && $n == 1) {
 483                print STDOUT "from refs/mediawiki/$remotename/master^0\n";
 484        }
 485        if ($content ne DELETED_CONTENT) {
 486                print STDOUT "M 644 inline $title.mw\n";
 487                literal_data($content);
 488                print STDOUT "\n\n";
 489        } else {
 490                print STDOUT "D $title.mw\n";
 491        }
 492
 493        # mediawiki revision number in the git note
 494        if ($full_import && $n == 1) {
 495                print STDOUT "reset refs/notes/$remotename/mediawiki\n";
 496        }
 497        print STDOUT "commit refs/notes/$remotename/mediawiki\n";
 498        print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 499        literal_data("Note added by git-mediawiki during import");
 500        if (!$full_import && $n == 1) {
 501                print STDOUT "from refs/notes/$remotename/mediawiki^0\n";
 502        }
 503        print STDOUT "N inline :$n\n";
 504        literal_data("mediawiki_revision: " . $commit{mw_revision});
 505        print STDOUT "\n\n";
 506}
 507
 508# parse a sequence of
 509# <cmd> <arg1>
 510# <cmd> <arg2>
 511# \n
 512# (like batch sequence of import and sequence of push statements)
 513sub get_more_refs {
 514        my $cmd = shift;
 515        my @refs;
 516        while (1) {
 517                my $line = <STDIN>;
 518                if ($line =~ m/^$cmd (.*)$/) {
 519                        push(@refs, $1);
 520                } elsif ($line eq "\n") {
 521                        return @refs;
 522                } else {
 523                        die("Invalid command in a '$cmd' batch: ". $_);
 524                }
 525        }
 526}
 527
 528sub mw_import {
 529        # multiple import commands can follow each other.
 530        my @refs = (shift, get_more_refs("import"));
 531        foreach my $ref (@refs) {
 532                mw_import_ref($ref);
 533        }
 534        print STDOUT "done\n";
 535}
 536
 537sub mw_import_ref {
 538        my $ref = shift;
 539        # The remote helper will call "import HEAD" and
 540        # "import refs/heads/master".
 541        # Since HEAD is a symbolic ref to master (by convention,
 542        # followed by the output of the command "list" that we gave),
 543        # we don't need to do anything in this case.
 544        if ($ref eq "HEAD") {
 545                return;
 546        }
 547
 548        mw_connect_maybe();
 549
 550        my @pages = get_mw_pages();
 551
 552        print STDERR "Searching revisions...\n";
 553        my $last_local = get_last_local_revision();
 554        my $fetch_from = $last_local + 1;
 555        if ($fetch_from == 1) {
 556                print STDERR ", fetching from beginning.\n";
 557        } else {
 558                print STDERR ", fetching from here.\n";
 559        }
 560        my ($n, @revisions) = fetch_mw_revisions(\@pages, $fetch_from);
 561
 562        # Creation of the fast-import stream
 563        print STDERR "Fetching & writing export data...\n";
 564
 565        $n = 0;
 566        my $last_timestamp = 0; # Placeholer in case $rev->timestamp is undefined
 567
 568        foreach my $pagerevid (sort {$a->{revid} <=> $b->{revid}} @revisions) {
 569                # fetch the content of the pages
 570                my $query = {
 571                        action => 'query',
 572                        prop => 'revisions',
 573                        rvprop => 'content|timestamp|comment|user|ids',
 574                        revids => $pagerevid->{revid},
 575                };
 576
 577                my $result = $mediawiki->api($query);
 578
 579                my $rev = pop(@{$result->{query}->{pages}->{$pagerevid->{pageid}}->{revisions}});
 580
 581                $n++;
 582
 583                my %commit;
 584                $commit{author} = $rev->{user} || 'Anonymous';
 585                $commit{comment} = $rev->{comment} || '*Empty MediaWiki Message*';
 586                $commit{title} = mediawiki_smudge_filename(
 587                        $result->{query}->{pages}->{$pagerevid->{pageid}}->{title}
 588                    );
 589                $commit{mw_revision} = $pagerevid->{revid};
 590                $commit{content} = mediawiki_smudge($rev->{'*'});
 591
 592                if (!defined($rev->{timestamp})) {
 593                        $last_timestamp++;
 594                } else {
 595                        $last_timestamp = $rev->{timestamp};
 596                }
 597                $commit{date} = DateTime::Format::ISO8601->parse_datetime($last_timestamp);
 598
 599                print STDERR "$n/", scalar(@revisions), ": Revision #$pagerevid->{revid} of $commit{title}\n";
 600
 601                import_file_revision(\%commit, ($fetch_from == 1), $n);
 602        }
 603
 604        if ($fetch_from == 1 && $n == 0) {
 605                print STDERR "You appear to have cloned an empty MediaWiki.\n";
 606                # Something has to be done remote-helper side. If nothing is done, an error is
 607                # thrown saying that HEAD is refering to unknown object 0000000000000000000
 608                # and the clone fails.
 609        }
 610}
 611
 612sub error_non_fast_forward {
 613        my $advice = run_git("config --bool advice.pushNonFastForward");
 614        chomp($advice);
 615        if ($advice ne "false") {
 616                # Native git-push would show this after the summary.
 617                # We can't ask it to display it cleanly, so print it
 618                # ourselves before.
 619                print STDERR "To prevent you from losing history, non-fast-forward updates were rejected\n";
 620                print STDERR "Merge the remote changes (e.g. 'git pull') before pushing again. See the\n";
 621                print STDERR "'Note about fast-forwards' section of 'git push --help' for details.\n";
 622        }
 623        print STDOUT "error $_[0] \"non-fast-forward\"\n";
 624        return 0;
 625}
 626
 627sub mw_push_file {
 628        my $diff_info = shift;
 629        # $diff_info contains a string in this format:
 630        # 100644 100644 <sha1_of_blob_before_commit> <sha1_of_blob_now> <status>
 631        my @diff_info_split = split(/[ \t]/, $diff_info);
 632
 633        # Filename, including .mw extension
 634        my $complete_file_name = shift;
 635        # Commit message
 636        my $summary = shift;
 637        # MediaWiki revision number. Keep the previous one by default,
 638        # in case there's no edit to perform.
 639        my $newrevid = shift;
 640
 641        my $new_sha1 = $diff_info_split[3];
 642        my $old_sha1 = $diff_info_split[2];
 643        my $page_created = ($old_sha1 eq NULL_SHA1);
 644        my $page_deleted = ($new_sha1 eq NULL_SHA1);
 645        $complete_file_name = mediawiki_clean_filename($complete_file_name);
 646
 647        if (substr($complete_file_name,-3) eq ".mw") {
 648                my $title = substr($complete_file_name,0,-3);
 649
 650                my $file_content;
 651                if ($page_deleted) {
 652                        # Deleting a page usually requires
 653                        # special priviledges. A common
 654                        # convention is to replace the page
 655                        # with this content instead:
 656                        $file_content = DELETED_CONTENT;
 657                } else {
 658                        $file_content = run_git("cat-file blob $new_sha1");
 659                }
 660
 661                mw_connect_maybe();
 662
 663                my $result = $mediawiki->edit( {
 664                        action => 'edit',
 665                        summary => $summary,
 666                        title => $title,
 667                        basetimestamp => $basetimestamps{$newrevid},
 668                        text => mediawiki_clean($file_content, $page_created),
 669                                  }, {
 670                                          skip_encoding => 1 # Helps with names with accentuated characters
 671                                  });
 672                if (!$result) {
 673                        if ($mediawiki->{error}->{code} == 3) {
 674                                # edit conflicts, considered as non-fast-forward
 675                                print STDERR 'Warning: Error ' .
 676                                    $mediawiki->{error}->{code} .
 677                                    ' from mediwiki: ' . $mediawiki->{error}->{details} .
 678                                    ".\n";
 679                                return ($newrevid, "non-fast-forward");
 680                        } else {
 681                                # Other errors. Shouldn't happen => just die()
 682                                die 'Fatal: Error ' .
 683                                    $mediawiki->{error}->{code} .
 684                                    ' from mediwiki: ' . $mediawiki->{error}->{details};
 685                        }
 686                }
 687                $newrevid = $result->{edit}->{newrevid};
 688                print STDERR "Pushed file: $new_sha1 - $title\n";
 689        } else {
 690                print STDERR "$complete_file_name not a mediawiki file (Not pushable on this version of git-remote-mediawiki).\n"
 691        }
 692        return ($newrevid, "ok");
 693}
 694
 695sub mw_push {
 696        # multiple push statements can follow each other
 697        my @refsspecs = (shift, get_more_refs("push"));
 698        my $pushed;
 699        for my $refspec (@refsspecs) {
 700                my ($force, $local, $remote) = $refspec =~ /^(\+)?([^:]*):([^:]*)$/
 701                    or die("Invalid refspec for push. Expected <src>:<dst> or +<src>:<dst>");
 702                if ($force) {
 703                        print STDERR "Warning: forced push not allowed on a MediaWiki.\n";
 704                }
 705                if ($local eq "") {
 706                        print STDERR "Cannot delete remote branch on a MediaWiki\n";
 707                        print STDOUT "error $remote cannot delete\n";
 708                        next;
 709                }
 710                if ($remote ne "refs/heads/master") {
 711                        print STDERR "Only push to the branch 'master' is supported on a MediaWiki\n";
 712                        print STDOUT "error $remote only master allowed\n";
 713                        next;
 714                }
 715                if (mw_push_revision($local, $remote)) {
 716                        $pushed = 1;
 717                }
 718        }
 719
 720        # Notify Git that the push is done
 721        print STDOUT "\n";
 722
 723        if ($pushed && $dumb_push) {
 724                print STDERR "Just pushed some revisions to MediaWiki.\n";
 725                print STDERR "The pushed revisions now have to be re-imported, and your current branch\n";
 726                print STDERR "needs to be updated with these re-imported commits. You can do this with\n";
 727                print STDERR "\n";
 728                print STDERR "  git pull --rebase\n";
 729                print STDERR "\n";
 730        }
 731}
 732
 733sub mw_push_revision {
 734        my $local = shift;
 735        my $remote = shift; # actually, this has to be "refs/heads/master" at this point.
 736        my $last_local_revid = get_last_local_revision();
 737        print STDERR ".\n"; # Finish sentence started by get_last_local_revision()
 738        my $last_remote_revid = get_last_remote_revision();
 739        my $mw_revision = $last_remote_revid;
 740
 741        # Get sha1 of commit pointed by local HEAD
 742        my $HEAD_sha1 = run_git("rev-parse $local 2>/dev/null"); chomp($HEAD_sha1);
 743        # Get sha1 of commit pointed by remotes/$remotename/master
 744        my $remoteorigin_sha1 = run_git("rev-parse refs/remotes/$remotename/master 2>/dev/null");
 745        chomp($remoteorigin_sha1);
 746
 747        if ($last_local_revid > 0 &&
 748            $last_local_revid < $last_remote_revid) {
 749                return error_non_fast_forward($remote);
 750        }
 751
 752        if ($HEAD_sha1 eq $remoteorigin_sha1) {
 753                # nothing to push
 754                return 0;
 755        }
 756
 757        # Get every commit in between HEAD and refs/remotes/origin/master,
 758        # including HEAD and refs/remotes/origin/master
 759        my @commit_pairs = ();
 760        if ($last_local_revid > 0) {
 761                my $parsed_sha1 = $remoteorigin_sha1;
 762                # Find a path from last MediaWiki commit to pushed commit
 763                while ($parsed_sha1 ne $HEAD_sha1) {
 764                        my @commit_info =  grep(/^$parsed_sha1/, split(/\n/, run_git("rev-list --children $local")));
 765                        if (!@commit_info) {
 766                                return error_non_fast_forward($remote);
 767                        }
 768                        my @commit_info_split = split(/ |\n/, $commit_info[0]);
 769                        # $commit_info_split[1] is the sha1 of the commit to export
 770                        # $commit_info_split[0] is the sha1 of its direct child
 771                        push(@commit_pairs, \@commit_info_split);
 772                        $parsed_sha1 = $commit_info_split[1];
 773                }
 774        } else {
 775                # No remote mediawiki revision. Export the whole
 776                # history (linearized with --first-parent)
 777                print STDERR "Warning: no common ancestor, pushing complete history\n";
 778                my $history = run_git("rev-list --first-parent --children $local");
 779                my @history = split('\n', $history);
 780                @history = @history[1..$#history];
 781                foreach my $line (reverse @history) {
 782                        my @commit_info_split = split(/ |\n/, $line);
 783                        push(@commit_pairs, \@commit_info_split);
 784                }
 785        }
 786
 787        foreach my $commit_info_split (@commit_pairs) {
 788                my $sha1_child = @{$commit_info_split}[0];
 789                my $sha1_commit = @{$commit_info_split}[1];
 790                my $diff_infos = run_git("diff-tree -r --raw -z $sha1_child $sha1_commit");
 791                # TODO: we could detect rename, and encode them with a #redirect on the wiki.
 792                # TODO: for now, it's just a delete+add
 793                my @diff_info_list = split(/\0/, $diff_infos);
 794                # Keep the first line of the commit message as mediawiki comment for the revision
 795                my $commit_msg = (split(/\n/, run_git("show --pretty=format:\"%s\" $sha1_commit")))[0];
 796                chomp($commit_msg);
 797                # Push every blob
 798                while (@diff_info_list) {
 799                        my $status;
 800                        # git diff-tree -z gives an output like
 801                        # <metadata>\0<filename1>\0
 802                        # <metadata>\0<filename2>\0
 803                        # and we've split on \0.
 804                        my $info = shift(@diff_info_list);
 805                        my $file = shift(@diff_info_list);
 806                        ($mw_revision, $status) = mw_push_file($info, $file, $commit_msg, $mw_revision);
 807                        if ($status eq "non-fast-forward") {
 808                                # we may already have sent part of the
 809                                # commit to MediaWiki, but it's too
 810                                # late to cancel it. Stop the push in
 811                                # the middle, but still give an
 812                                # accurate error message.
 813                                return error_non_fast_forward($remote);
 814                        }
 815                        if ($status ne "ok") {
 816                                die("Unknown error from mw_push_file()");
 817                        }
 818                }
 819                unless ($dumb_push) {
 820                        run_git("notes --ref=$remotename/mediawiki add -m \"mediawiki_revision: $mw_revision\" $sha1_commit");
 821                        run_git("update-ref -m \"Git-MediaWiki push\" refs/mediawiki/$remotename/master $sha1_commit $sha1_child");
 822                }
 823        }
 824
 825        print STDOUT "ok $remote\n";
 826        return 1;
 827}