contrib/mw-to-git/git-remote-mediawiki

   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 # - Several strategies are provided to fetch modifications from the
  17 #   wiki, but no automatic heuristics is provided, the user has
  18 #   to understand and chose which strategy is appropriate for him.
  19 #
  20 # - Git renames could be turned into MediaWiki renames (see TODO
  21 #   below)
  22 #
  23 # - No way to import "one page, and all pages included in it"
  24 #
  25 # - Multiple remote MediaWikis have not been very well tested.
  26
  27 use strict;
  28 use MediaWiki::API;
  29 use DateTime::Format::ISO8601;
  30
  31 # By default, use UTF-8 to communicate with Git and the user
  32 binmode STDERR, ":utf8";
  33 binmode STDOUT, ":utf8";
  34
  35 use URI::Escape;
  36 use IPC::Open2;
  37
  38 use warnings;
  39
  40 # Mediawiki filenames can contain forward slashes. This variable decides by which pattern they should be replaced
  41 use constant SLASH_REPLACEMENT => "%2F";
  42
  43 # It's not always possible to delete pages (may require some
  44 # priviledges). Deleted pages are replaced with this content.
  45 use constant DELETED_CONTENT => "[[Category:Deleted]]\n";
  46
  47 # It's not possible to create empty pages. New empty files in Git are
  48 # sent with this content instead.
  49 use constant EMPTY_CONTENT => "<!-- empty page -->\n";
  50
  51 # used to reflect file creation or deletion in diff.
  52 use constant NULL_SHA1 => "0000000000000000000000000000000000000000";
  53
  54 # Used on Git's side to reflect empty edit messages on the wiki
  55 use constant EMPTY_MESSAGE => '*Empty MediaWiki Message*';
  56
  57 my $remotename = $ARGV[0];
  58 my $url = $ARGV[1];
  59
  60 # Accept both space-separated and multiple keys in config file.
  61 # Spaces should be written as _ anyway because we'll use chomp.
  62 my @tracked_pages = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".pages"));
  63 chomp(@tracked_pages);
  64
  65 # Just like @tracked_pages, but for MediaWiki categories.
  66 my @tracked_categories = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".categories"));
  67 chomp(@tracked_categories);
  68
  69 # Import media files on pull
  70 my $import_media = run_git("config --get --bool remote.". $remotename .".mediaimport");
  71 chomp($import_media);
  72 $import_media = ($import_media eq "true");
  73
  74 # Export media files on push
  75 my $export_media = run_git("config --get --bool remote.". $remotename .".mediaexport");
  76 chomp($export_media);
  77 $export_media = !($export_media eq "false");
  78
  79 my $wiki_login = run_git("config --get remote.". $remotename .".mwLogin");
  80 # Note: mwPassword is discourraged. Use the credential system instead.
  81 my $wiki_passwd = run_git("config --get remote.". $remotename .".mwPassword");
  82 my $wiki_domain = run_git("config --get remote.". $remotename .".mwDomain");
  83 chomp($wiki_login);
  84 chomp($wiki_passwd);
  85 chomp($wiki_domain);
  86
  87 # Import only last revisions (both for clone and fetch)
  88 my $shallow_import = run_git("config --get --bool remote.". $remotename .".shallow");
  89 chomp($shallow_import);
  90 $shallow_import = ($shallow_import eq "true");
  91
  92 # Fetch (clone and pull) by revisions instead of by pages. This behavior
  93 # is more efficient when we have a wiki with lots of pages and we fetch
  94 # the revisions quite often so that they concern only few pages.
  95 # Possible values:
  96 # - by_rev: perform one query per new revision on the remote wiki
  97 # - by_page: query each tracked page for new revision
  98 my $fetch_strategy = run_git("config --get remote.$remotename.fetchStrategy");
  99 unless ($fetch_strategy) {
 100         $fetch_strategy = run_git("config --get mediawiki.fetchStrategy");
 101 }
 102 chomp($fetch_strategy);
 103 unless ($fetch_strategy) {
 104         $fetch_strategy = "by_page";
 105 }
 106
 107 # Dumb push: don't update notes and mediawiki ref to reflect the last push.
 108 #
 109 # Configurable with mediawiki.dumbPush, or per-remote with
 110 # remote.<remotename>.dumbPush.
 111 #
 112 # This means the user will have to re-import the just-pushed
 113 # revisions. On the other hand, this means that the Git revisions
 114 # corresponding to MediaWiki revisions are all imported from the wiki,
 115 # regardless of whether they were initially created in Git or from the
 116 # web interface, hence all users will get the same history (i.e. if
 117 # the push from Git to MediaWiki loses some information, everybody
 118 # will get the history with information lost). If the import is
 119 # deterministic, this means everybody gets the same sha1 for each
 120 # MediaWiki revision.
 121 my $dumb_push = run_git("config --get --bool remote.$remotename.dumbPush");
 122 unless ($dumb_push) {
 123         $dumb_push = run_git("config --get --bool mediawiki.dumbPush");
 124 }
 125 chomp($dumb_push);
 126 $dumb_push = ($dumb_push eq "true");
 127
 128 my $wiki_name = $url;
 129 $wiki_name =~ s/[^\/]*:\/\///;
 130 # If URL is like http://user:password@example.com/, we clearly don't
 131 # want the password in $wiki_name. While we're there, also remove user
 132 # and '@' sign, to avoid author like MWUser@HTTPUser@host.com
 133 $wiki_name =~ s/^.*@//;
 134
 135 # Commands parser
 136 my $entry;
 137 my @cmd;
 138 while (<STDIN>) {
 139         chomp;
 140         @cmd = split(/ /);
 141         if (defined($cmd[0])) {
 142                 # Line not blank
 143                 if ($cmd[0] eq "capabilities") {
 144                         die("Too many arguments for capabilities") unless (!defined($cmd[1]));
 145                         mw_capabilities();
 146                 } elsif ($cmd[0] eq "list") {
 147                         die("Too many arguments for list") unless (!defined($cmd[2]));
 148                         mw_list($cmd[1]);
 149                 } elsif ($cmd[0] eq "import") {
 150                         die("Invalid arguments for import") unless ($cmd[1] ne "" && !defined($cmd[2]));
 151                         mw_import($cmd[1]);
 152                 } elsif ($cmd[0] eq "option") {
 153                         die("Too many arguments for option") unless ($cmd[1] ne "" && $cmd[2] ne "" && !defined($cmd[3]));
 154                         mw_option($cmd[1],$cmd[2]);
 155                 } elsif ($cmd[0] eq "push") {
 156                         mw_push($cmd[1]);
 157                 } else {
 158                         print STDERR "Unknown command. Aborting...\n";
 159                         last;
 160                 }
 161         } else {
 162                 # blank line: we should terminate
 163                 last;
 164         }
 165
 166         BEGIN { $| = 1 } # flush STDOUT, to make sure the previous
 167                          # command is fully processed.
 168 }
 169
 170 ########################## Functions ##############################
 171
 172 ## credential API management (generic functions)
 173
 174 sub credential_from_url {
 175         my $url = shift;
 176         my $parsed = URI->new($url);
 177         my %credential;
 178
 179         if ($parsed->scheme) {
 180                 $credential{protocol} = $parsed->scheme;
 181         }
 182         if ($parsed->host) {
 183                 $credential{host} = $parsed->host;
 184         }
 185         if ($parsed->path) {
 186                 $credential{path} = $parsed->path;
 187         }
 188         if ($parsed->userinfo) {
 189                 if ($parsed->userinfo =~ /([^:]*):(.*)/) {
 190                         $credential{username} = $1;
 191                         $credential{password} = $2;
 192                 } else {
 193                         $credential{username} = $parsed->userinfo;
 194                 }
 195         }
 196
 197         return %credential;
 198 }
 199
 200 sub credential_read {
 201         my %credential;
 202         my $reader = shift;
 203         my $op = shift;
 204         while (<$reader>) {
 205                 my ($key, $value) = /([^=]*)=(.*)/;
 206                 if (not defined $key) {
 207                         die "ERROR receiving response from git credential $op:\n$_\n";
 208                 }
 209                 $credential{$key} = $value;
 210         }
 211         return %credential;
 212 }
 213
 214 sub credential_write {
 215         my $credential = shift;
 216         my $writer = shift;
 217         while (my ($key, $value) = each(%$credential) ) {
 218                 if ($value) {
 219                         print $writer "$key=$value\n";
 220                 }
 221         }
 222 }
 223
 224 sub credential_run {
 225         my $op = shift;
 226         my $credential = shift;
 227         my $pid = open2(my $reader, my $writer, "git credential $op");
 228         credential_write($credential, $writer);
 229         print $writer "\n";
 230         close($writer);
 231
 232         if ($op eq "fill") {
 233                 %$credential = credential_read($reader, $op);
 234         } else {
 235                 if (<$reader>) {
 236                         die "ERROR while running git credential $op:\n$_";
 237                 }
 238         }
 239         close($reader);
 240         waitpid($pid, 0);
 241         my $child_exit_status = $? >> 8;
 242         if ($child_exit_status != 0) {
 243                 die "'git credential $op' failed with code $child_exit_status.";
 244         }
 245 }
 246
 247 # MediaWiki API instance, created lazily.
 248 my $mediawiki;
 249
 250 sub mw_connect_maybe {
 251         if ($mediawiki) {
 252                 return;
 253         }
 254         $mediawiki = MediaWiki::API->new;
 255         $mediawiki->{config}->{api_url} = "$url/api.php";
 256         if ($wiki_login) {
 257                 my %credential = credential_from_url($url);
 258                 $credential{username} = $wiki_login;
 259                 $credential{password} = $wiki_passwd;
 260                 credential_run("fill", \%credential);
 261                 my $request = {lgname => $credential{username},
 262                                lgpassword => $credential{password},
 263                                lgdomain => $wiki_domain};
 264                 if ($mediawiki->login($request)) {
 265                         credential_run("approve", \%credential);
 266                         print STDERR "Logged in mediawiki user \"$credential{username}\".\n";
 267                 } else {
 268                         print STDERR "Failed to log in mediawiki user \"$credential{username}\" on $url\n";
 269                         print STDERR "  (error " .
 270                                 $mediawiki->{error}->{code} . ': ' .
 271                                 $mediawiki->{error}->{details} . ")\n";
 272                         credential_run("reject", \%credential);
 273                         exit 1;
 274                 }
 275         }
 276 }
 277
 278 ## Functions for listing pages on the remote wiki
 279 sub get_mw_tracked_pages {
 280         my $pages = shift;
 281         get_mw_page_list(\@tracked_pages, $pages);
 282 }
 283
 284 sub get_mw_page_list {
 285         my $page_list = shift;
 286         my $pages = shift;
 287         my @some_pages = @$page_list;
 288         while (@some_pages) {
 289                 my $last = 50;
 290                 if ($#some_pages < $last) {
 291                         $last = $#some_pages;
 292                 }
 293                 my @slice = @some_pages[0..$last];
 294                 get_mw_first_pages(\@slice, $pages);
 295                 @some_pages = @some_pages[51..$#some_pages];
 296         }
 297 }
 298
 299 sub get_mw_tracked_categories {
 300         my $pages = shift;
 301         foreach my $category (@tracked_categories) {
 302                 if (index($category, ':') < 0) {
 303                         # Mediawiki requires the Category
 304                         # prefix, but let's not force the user
 305                         # to specify it.
 306                         $category = "Category:" . $category;
 307                 }
 308                 my $mw_pages = $mediawiki->list( {
 309                         action => 'query',
 310                         list => 'categorymembers',
 311                         cmtitle => $category,
 312                         cmlimit => 'max' } )
 313                         || die $mediawiki->{error}->{code} . ': '
 314                                 . $mediawiki->{error}->{details};
 315                 foreach my $page (@{$mw_pages}) {
 316                         $pages->{$page->{title}} = $page;
 317                 }
 318         }
 319 }
 320
 321 sub get_mw_all_pages {
 322         my $pages = shift;
 323         # No user-provided list, get the list of pages from the API.
 324         my $mw_pages = $mediawiki->list({
 325                 action => 'query',
 326                 list => 'allpages',
 327                 aplimit => 'max'
 328         });
 329         if (!defined($mw_pages)) {
 330                 print STDERR "fatal: could not get the list of wiki pages.\n";
 331                 print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 332                 print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 333                 exit 1;
 334         }
 335         foreach my $page (@{$mw_pages}) {
 336                 $pages->{$page->{title}} = $page;
 337         }
 338 }
 339
 340 # queries the wiki for a set of pages. Meant to be used within a loop
 341 # querying the wiki for slices of page list.
 342 sub get_mw_first_pages {
 343         my $some_pages = shift;
 344         my @some_pages = @{$some_pages};
 345
 346         my $pages = shift;
 347
 348         # pattern 'page1|page2|...' required by the API
 349         my $titles = join('|', @some_pages);
 350
 351         my $mw_pages = $mediawiki->api({
 352                 action => 'query',
 353                 titles => $titles,
 354         });
 355         if (!defined($mw_pages)) {
 356                 print STDERR "fatal: could not query the list of wiki pages.\n";
 357                 print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 358                 print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 359                 exit 1;
 360         }
 361         while (my ($id, $page) = each(%{$mw_pages->{query}->{pages}})) {
 362                 if ($id < 0) {
 363                         print STDERR "Warning: page $page->{title} not found on wiki\n";
 364                 } else {
 365                         $pages->{$page->{title}} = $page;
 366                 }
 367         }
 368 }
 369
 370 # Get the list of pages to be fetched according to configuration.
 371 sub get_mw_pages {
 372         mw_connect_maybe();
 373
 374         print STDERR "Listing pages on remote wiki...\n";
 375
 376         my %pages; # hash on page titles to avoid duplicates
 377         my $user_defined;
 378         if (@tracked_pages) {
 379                 $user_defined = 1;
 380                 # The user provided a list of pages titles, but we
 381                 # still need to query the API to get the page IDs.
 382                 get_mw_tracked_pages(\%pages);
 383         }
 384         if (@tracked_categories) {
 385                 $user_defined = 1;
 386                 get_mw_tracked_categories(\%pages);
 387         }
 388         if (!$user_defined) {
 389                 get_mw_all_pages(\%pages);
 390         }
 391         if ($import_media) {
 392                 print STDERR "Getting media files for selected pages...\n";
 393                 if ($user_defined) {
 394                         get_linked_mediafiles(\%pages);
 395                 } else {
 396                         get_all_mediafiles(\%pages);
 397                 }
 398         }
 399         print STDERR (scalar keys %pages) . " pages found.\n";
 400         return %pages;
 401 }
 402
 403 # usage: $out = run_git("command args");
 404 #        $out = run_git("command args", "raw"); # don't interpret output as UTF-8.
 405 sub run_git {
 406         my $args = shift;
 407         my $encoding = (shift || "encoding(UTF-8)");
 408         open(my $git, "-|:$encoding", "git " . $args);
 409         my $res = do { local $/; <$git> };
 410         close($git);
 411
 412         return $res;
 413 }
 414
 415
 416 sub get_all_mediafiles {
 417         my $pages = shift;
 418         # Attach list of all pages for media files from the API,
 419         # they are in a different namespace, only one namespace
 420         # can be queried at the same moment
 421         my $mw_pages = $mediawiki->list({
 422                 action => 'query',
 423                 list => 'allpages',
 424                 apnamespace => get_mw_namespace_id("File"),
 425                 aplimit => 'max'
 426         });
 427         if (!defined($mw_pages)) {
 428                 print STDERR "fatal: could not get the list of pages for media files.\n";
 429                 print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 430                 print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 431                 exit 1;
 432         }
 433         foreach my $page (@{$mw_pages}) {
 434                 $pages->{$page->{title}} = $page;
 435         }
 436 }
 437
 438 sub get_linked_mediafiles {
 439         my $pages = shift;
 440         my @titles = map $_->{title}, values(%{$pages});
 441
 442         # The query is split in small batches because of the MW API limit of
 443         # the number of links to be returned (500 links max).
 444         my $batch = 10;
 445         while (@titles) {
 446                 if ($#titles < $batch) {
 447                         $batch = $#titles;
 448                 }
 449                 my @slice = @titles[0..$batch];
 450
 451                 # pattern 'page1|page2|...' required by the API
 452                 my $mw_titles = join('|', @slice);
 453
 454                 # Media files could be included or linked from
 455                 # a page, get all related
 456                 my $query = {
 457                         action => 'query',
 458                         prop => 'links|images',
 459                         titles => $mw_titles,
 460                         plnamespace => get_mw_namespace_id("File"),
 461                         pllimit => 'max'
 462                 };
 463                 my $result = $mediawiki->api($query);
 464
 465                 while (my ($id, $page) = each(%{$result->{query}->{pages}})) {
 466                         my @media_titles;
 467                         if (defined($page->{links})) {
 468                                 my @link_titles = map $_->{title}, @{$page->{links}};
 469                                 push(@media_titles, @link_titles);
 470                         }
 471                         if (defined($page->{images})) {
 472                                 my @image_titles = map $_->{title}, @{$page->{images}};
 473                                 push(@media_titles, @image_titles);
 474                         }
 475                         if (@media_titles) {
 476                                 get_mw_page_list(\@media_titles, $pages);
 477                         }
 478                 }
 479
 480                 @titles = @titles[($batch+1)..$#titles];
 481         }
 482 }
 483
 484 sub get_mw_mediafile_for_page_revision {
 485         # Name of the file on Wiki, with the prefix.
 486         my $filename = shift;
 487         my $timestamp = shift;
 488         my %mediafile;
 489
 490         # Search if on a media file with given timestamp exists on
 491         # MediaWiki. In that case download the file.
 492         my $query = {
 493                 action => 'query',
 494                 prop => 'imageinfo',
 495                 titles => "File:" . $filename,
 496                 iistart => $timestamp,
 497                 iiend => $timestamp,
 498                 iiprop => 'timestamp|archivename|url',
 499                 iilimit => 1
 500         };
 501         my $result = $mediawiki->api($query);
 502
 503         my ($fileid, $file) = each( %{$result->{query}->{pages}} );
 504         # If not defined it means there is no revision of the file for
 505         # given timestamp.
 506         if (defined($file->{imageinfo})) {
 507                 $mediafile{title} = $filename;
 508
 509                 my $fileinfo = pop(@{$file->{imageinfo}});
 510                 $mediafile{timestamp} = $fileinfo->{timestamp};
 511                 # Mediawiki::API's download function doesn't support https URLs
 512                 # and can't download old versions of files.
 513                 print STDERR "\tDownloading file $mediafile{title}, version $mediafile{timestamp}\n";
 514                 $mediafile{content} = download_mw_mediafile($fileinfo->{url});
 515         }
 516         return %mediafile;
 517 }
 518
 519 sub download_mw_mediafile {
 520         my $url = shift;
 521
 522         my $response = $mediawiki->{ua}->get($url);
 523         if ($response->code == 200) {
 524                 return $response->decoded_content;
 525         } else {
 526                 print STDERR "Error downloading mediafile from :\n";
 527                 print STDERR "URL: $url\n";
 528                 print STDERR "Server response: " . $response->code . " " . $response->message . "\n";
 529                 exit 1;
 530         }
 531 }
 532
 533 sub get_last_local_revision {
 534         # Get note regarding last mediawiki revision
 535         my $note = run_git("notes --ref=$remotename/mediawiki show refs/mediawiki/$remotename/master 2>/dev/null");
 536         my @note_info = split(/ /, $note);
 537
 538         my $lastrevision_number;
 539         if (!(defined($note_info[0]) && $note_info[0] eq "mediawiki_revision:")) {
 540                 print STDERR "No previous mediawiki revision found";
 541                 $lastrevision_number = 0;
 542         } else {
 543                 # Notes are formatted : mediawiki_revision: #number
 544                 $lastrevision_number = $note_info[1];
 545                 chomp($lastrevision_number);
 546                 print STDERR "Last local mediawiki revision found is $lastrevision_number";
 547         }
 548         return $lastrevision_number;
 549 }
 550
 551 # Remember the timestamp corresponding to a revision id.
 552 my %basetimestamps;
 553
 554 # Get the last remote revision without taking in account which pages are
 555 # tracked or not. This function makes a single request to the wiki thus
 556 # avoid a loop onto all tracked pages. This is useful for the fetch-by-rev
 557 # option.
 558 sub get_last_global_remote_rev {
 559         mw_connect_maybe();
 560
 561         my $query = {
 562                 action => 'query',
 563                 list => 'recentchanges',
 564                 prop => 'revisions',
 565                 rclimit => '1',
 566                 rcdir => 'older',
 567         };
 568         my $result = $mediawiki->api($query);
 569         return $result->{query}->{recentchanges}[0]->{revid};
 570 }
 571
 572 # Get the last remote revision concerning the tracked pages and the tracked
 573 # categories.
 574 sub get_last_remote_revision {
 575         mw_connect_maybe();
 576
 577         my %pages_hash = get_mw_pages();
 578         my @pages = values(%pages_hash);
 579
 580         my $max_rev_num = 0;
 581
 582         foreach my $page (@pages) {
 583                 my $id = $page->{pageid};
 584
 585                 my $query = {
 586                         action => 'query',
 587                         prop => 'revisions',
 588                         rvprop => 'ids|timestamp',
 589                         pageids => $id,
 590                 };
 591
 592                 my $result = $mediawiki->api($query);
 593
 594                 my $lastrev = pop(@{$result->{query}->{pages}->{$id}->{revisions}});
 595
 596                 $basetimestamps{$lastrev->{revid}} = $lastrev->{timestamp};
 597
 598                 $max_rev_num = ($lastrev->{revid} > $max_rev_num ? $lastrev->{revid} : $max_rev_num);
 599         }
 600
 601         print STDERR "Last remote revision found is $max_rev_num.\n";
 602         return $max_rev_num;
 603 }
 604
 605 # Clean content before sending it to MediaWiki
 606 sub mediawiki_clean {
 607         my $string = shift;
 608         my $page_created = shift;
 609         # Mediawiki does not allow blank space at the end of a page and ends with a single \n.
 610         # This function right trims a string and adds a \n at the end to follow this rule
 611         $string =~ s/\s+$//;
 612         if ($string eq "" && $page_created) {
 613                 # Creating empty pages is forbidden.
 614                 $string = EMPTY_CONTENT;
 615         }
 616         return $string."\n";
 617 }
 618
 619 # Filter applied on MediaWiki data before adding them to Git
 620 sub mediawiki_smudge {
 621         my $string = shift;
 622         if ($string eq EMPTY_CONTENT) {
 623                 $string = "";
 624         }
 625         # This \n is important. This is due to mediawiki's way to handle end of files.
 626         return $string."\n";
 627 }
 628
 629 sub mediawiki_clean_filename {
 630         my $filename = shift;
 631         $filename =~ s/@{[SLASH_REPLACEMENT]}/\//g;
 632         # [, ], |, {, and } are forbidden by MediaWiki, even URL-encoded.
 633         # Do a variant of URL-encoding, i.e. looks like URL-encoding,
 634         # but with _ added to prevent MediaWiki from thinking this is
 635         # an actual special character.
 636         $filename =~ s/[\[\]\{\}\|]/sprintf("_%%_%x", ord($&))/ge;
 637         # If we use the uri escape before
 638         # we should unescape here, before anything
 639
 640         return $filename;
 641 }
 642
 643 sub mediawiki_smudge_filename {
 644         my $filename = shift;
 645         $filename =~ s/\//@{[SLASH_REPLACEMENT]}/g;
 646         $filename =~ s/ /_/g;
 647         # Decode forbidden characters encoded in mediawiki_clean_filename
 648         $filename =~ s/_%_([0-9a-fA-F][0-9a-fA-F])/sprintf("%c", hex($1))/ge;
 649         return $filename;
 650 }
 651
 652 sub literal_data {
 653         my ($content) = @_;
 654         print STDOUT "data ", bytes::length($content), "\n", $content;
 655 }
 656
 657 sub literal_data_raw {
 658         # Output possibly binary content.
 659         my ($content) = @_;
 660         # Avoid confusion between size in bytes and in characters
 661         utf8::downgrade($content);
 662         binmode STDOUT, ":raw";
 663         print STDOUT "data ", bytes::length($content), "\n", $content;
 664         binmode STDOUT, ":utf8";
 665 }
 666
 667 sub mw_capabilities {
 668         # Revisions are imported to the private namespace
 669         # refs/mediawiki/$remotename/ by the helper and fetched into
 670         # refs/remotes/$remotename later by fetch.
 671         print STDOUT "refspec refs/heads/*:refs/mediawiki/$remotename/*\n";
 672         print STDOUT "import\n";
 673         print STDOUT "list\n";
 674         print STDOUT "push\n";
 675         print STDOUT "\n";
 676 }
 677
 678 sub mw_list {
 679         # MediaWiki do not have branches, we consider one branch arbitrarily
 680         # called master, and HEAD pointing to it.
 681         print STDOUT "? refs/heads/master\n";
 682         print STDOUT "\@refs/heads/master HEAD\n";
 683         print STDOUT "\n";
 684 }
 685
 686 sub mw_option {
 687         print STDERR "remote-helper command 'option $_[0]' not yet implemented\n";
 688         print STDOUT "unsupported\n";
 689 }
 690
 691 sub fetch_mw_revisions_for_page {
 692         my $page = shift;
 693         my $id = shift;
 694         my $fetch_from = shift;
 695         my @page_revs = ();
 696         my $query = {
 697                 action => 'query',
 698                 prop => 'revisions',
 699                 rvprop => 'ids',
 700                 rvdir => 'newer',
 701                 rvstartid => $fetch_from,
 702                 rvlimit => 500,
 703                 pageids => $id,
 704         };
 705
 706         my $revnum = 0;
 707         # Get 500 revisions at a time due to the mediawiki api limit
 708         while (1) {
 709                 my $result = $mediawiki->api($query);
 710
 711                 # Parse each of those 500 revisions
 712                 foreach my $revision (@{$result->{query}->{pages}->{$id}->{revisions}}) {
 713                         my $page_rev_ids;
 714                         $page_rev_ids->{pageid} = $page->{pageid};
 715                         $page_rev_ids->{revid} = $revision->{revid};
 716                         push(@page_revs, $page_rev_ids);
 717                         $revnum++;
 718                 }
 719                 last unless $result->{'query-continue'};
 720                 $query->{rvstartid} = $result->{'query-continue'}->{revisions}->{rvstartid};
 721         }
 722         if ($shallow_import && @page_revs) {
 723                 print STDERR "  Found 1 revision (shallow import).\n";
 724                 @page_revs = sort {$b->{revid} <=> $a->{revid}} (@page_revs);
 725                 return $page_revs[0];
 726         }
 727         print STDERR "  Found ", $revnum, " revision(s).\n";
 728         return @page_revs;
 729 }
 730
 731 sub fetch_mw_revisions {
 732         my $pages = shift; my @pages = @{$pages};
 733         my $fetch_from = shift;
 734
 735         my @revisions = ();
 736         my $n = 1;
 737         foreach my $page (@pages) {
 738                 my $id = $page->{pageid};
 739
 740                 print STDERR "page $n/", scalar(@pages), ": ". $page->{title} ."\n";
 741                 $n++;
 742                 my @page_revs = fetch_mw_revisions_for_page($page, $id, $fetch_from);
 743                 @revisions = (@page_revs, @revisions);
 744         }
 745
 746         return ($n, @revisions);
 747 }
 748
 749 sub import_file_revision {
 750         my $commit = shift;
 751         my %commit = %{$commit};
 752         my $full_import = shift;
 753         my $n = shift;
 754         my $mediafile = shift;
 755         my %mediafile;
 756         if ($mediafile) {
 757                 %mediafile = %{$mediafile};
 758         }
 759
 760         my $title = $commit{title};
 761         my $comment = $commit{comment};
 762         my $content = $commit{content};
 763         my $author = $commit{author};
 764         my $date = $commit{date};
 765
 766         print STDOUT "commit refs/mediawiki/$remotename/master\n";
 767         print STDOUT "mark :$n\n";
 768         print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 769         literal_data($comment);
 770
 771         # If it's not a clone, we need to know where to start from
 772         if (!$full_import && $n == 1) {
 773                 print STDOUT "from refs/mediawiki/$remotename/master^0\n";
 774         }
 775         if ($content ne DELETED_CONTENT) {
 776                 print STDOUT "M 644 inline $title.mw\n";
 777                 literal_data($content);
 778                 if (%mediafile) {
 779                         print STDOUT "M 644 inline $mediafile{title}\n";
 780                         literal_data_raw($mediafile{content});
 781                 }
 782                 print STDOUT "\n\n";
 783         } else {
 784                 print STDOUT "D $title.mw\n";
 785         }
 786
 787         # mediawiki revision number in the git note
 788         if ($full_import && $n == 1) {
 789                 print STDOUT "reset refs/notes/$remotename/mediawiki\n";
 790         }
 791         print STDOUT "commit refs/notes/$remotename/mediawiki\n";
 792         print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 793         literal_data("Note added by git-mediawiki during import");
 794         if (!$full_import && $n == 1) {
 795                 print STDOUT "from refs/notes/$remotename/mediawiki^0\n";
 796         }
 797         print STDOUT "N inline :$n\n";
 798         literal_data("mediawiki_revision: " . $commit{mw_revision});
 799         print STDOUT "\n\n";
 800 }
 801
 802 # parse a sequence of
 803 # <cmd> <arg1>
 804 # <cmd> <arg2>
 805 # \n
 806 # (like batch sequence of import and sequence of push statements)
 807 sub get_more_refs {
 808         my $cmd = shift;
 809         my @refs;
 810         while (1) {
 811                 my $line = <STDIN>;
 812                 if ($line =~ m/^$cmd (.*)$/) {
 813                         push(@refs, $1);
 814                 } elsif ($line eq "\n") {
 815                         return @refs;
 816                 } else {
 817                         die("Invalid command in a '$cmd' batch: ". $_);
 818                 }
 819         }
 820 }
 821
 822 sub mw_import {
 823         # multiple import commands can follow each other.
 824         my @refs = (shift, get_more_refs("import"));
 825         foreach my $ref (@refs) {
 826                 mw_import_ref($ref);
 827         }
 828         print STDOUT "done\n";
 829 }
 830
 831 sub mw_import_ref {
 832         my $ref = shift;
 833         # The remote helper will call "import HEAD" and
 834         # "import refs/heads/master".
 835         # Since HEAD is a symbolic ref to master (by convention,
 836         # followed by the output of the command "list" that we gave),
 837         # we don't need to do anything in this case.
 838         if ($ref eq "HEAD") {
 839                 return;
 840         }
 841
 842         mw_connect_maybe();
 843
 844         print STDERR "Searching revisions...\n";
 845         my $last_local = get_last_local_revision();
 846         my $fetch_from = $last_local + 1;
 847         if ($fetch_from == 1) {
 848                 print STDERR ", fetching from beginning.\n";
 849         } else {
 850                 print STDERR ", fetching from here.\n";
 851         }
 852
 853         my $n = 0;
 854         if ($fetch_strategy eq "by_rev") {
 855                 print STDERR "Fetching & writing export data by revs...\n";
 856                 $n = mw_import_ref_by_revs($fetch_from);
 857         } elsif ($fetch_strategy eq "by_page") {
 858                 print STDERR "Fetching & writing export data by pages...\n";
 859                 $n = mw_import_ref_by_pages($fetch_from);
 860         } else {
 861                 print STDERR "fatal: invalid fetch strategy \"$fetch_strategy\".\n";
 862                 print STDERR "Check your configuration variables remote.$remotename.fetchStrategy and mediawiki.fetchStrategy\n";
 863                 exit 1;
 864         }
 865
 866         if ($fetch_from == 1 && $n == 0) {
 867                 print STDERR "You appear to have cloned an empty MediaWiki.\n";
 868                 # Something has to be done remote-helper side. If nothing is done, an error is
 869                 # thrown saying that HEAD is refering to unknown object 0000000000000000000
 870                 # and the clone fails.
 871         }
 872 }
 873
 874 sub mw_import_ref_by_pages {
 875
 876         my $fetch_from = shift;
 877         my %pages_hash = get_mw_pages();
 878         my @pages = values(%pages_hash);
 879
 880         my ($n, @revisions) = fetch_mw_revisions(\@pages, $fetch_from);
 881
 882         @revisions = sort {$a->{revid} <=> $b->{revid}} @revisions;
 883         my @revision_ids = map $_->{revid}, @revisions;
 884
 885         return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 886 }
 887
 888 sub mw_import_ref_by_revs {
 889
 890         my $fetch_from = shift;
 891         my %pages_hash = get_mw_pages();
 892
 893         my $last_remote = get_last_global_remote_rev();
 894         my @revision_ids = $fetch_from..$last_remote;
 895         return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 896 }
 897
 898 # Import revisions given in second argument (array of integers).
 899 # Only pages appearing in the third argument (hash indexed by page titles)
 900 # will be imported.
 901 sub mw_import_revids {
 902         my $fetch_from = shift;
 903         my $revision_ids = shift;
 904         my $pages = shift;
 905
 906         my $n = 0;
 907         my $n_actual = 0;
 908         my $last_timestamp = 0; # Placeholer in case $rev->timestamp is undefined
 909
 910         foreach my $pagerevid (@$revision_ids) {
 911                 # fetch the content of the pages
 912                 my $query = {
 913                         action => 'query',
 914                         prop => 'revisions',
 915                         rvprop => 'content|timestamp|comment|user|ids',
 916                         revids => $pagerevid,
 917                 };
 918
 919                 my $result = $mediawiki->api($query);
 920
 921                 if (!$result) {
 922                         die "Failed to retrieve modified page for revision $pagerevid";
 923                 }
 924
 925                 if (!defined($result->{query}->{pages})) {
 926                         die "Invalid revision $pagerevid.";
 927                 }
 928
 929                 my @result_pages = values(%{$result->{query}->{pages}});
 930                 my $result_page = $result_pages[0];
 931                 my $rev = $result_pages[0]->{revisions}->[0];
 932
 933                 # Count page even if we skip it, since we display
 934                 # $n/$total and $total includes skipped pages.
 935                 $n++;
 936
 937                 my $page_title = $result_page->{title};
 938
 939                 if (!exists($pages->{$page_title})) {
 940                         print STDERR "$n/", scalar(@$revision_ids),
 941                                 ": Skipping revision #$rev->{revid} of $page_title\n";
 942                         next;
 943                 }
 944
 945                 $n_actual++;
 946
 947                 my %commit;
 948                 $commit{author} = $rev->{user} || 'Anonymous';
 949                 $commit{comment} = $rev->{comment} || EMPTY_MESSAGE;
 950                 $commit{title} = mediawiki_smudge_filename($page_title);
 951                 $commit{mw_revision} = $rev->{revid};
 952                 $commit{content} = mediawiki_smudge($rev->{'*'});
 953
 954                 if (!defined($rev->{timestamp})) {
 955                         $last_timestamp++;
 956                 } else {
 957                         $last_timestamp = $rev->{timestamp};
 958                 }
 959                 $commit{date} = DateTime::Format::ISO8601->parse_datetime($last_timestamp);
 960
 961                 # Differentiates classic pages and media files.
 962                 my ($namespace, $filename) = $page_title =~ /^([^:]*):(.*)$/;
 963                 my %mediafile;
 964                 if ($namespace && get_mw_namespace_id($namespace) == get_mw_namespace_id("File")) {
 965                         %mediafile = get_mw_mediafile_for_page_revision($filename, $rev->{timestamp});
 966                 }
 967                 # If this is a revision of the media page for new version
 968                 # of a file do one common commit for both file and media page.
 969                 # Else do commit only for that page.
 970                 print STDERR "$n/", scalar(@$revision_ids), ": Revision #$rev->{revid} of $commit{title}\n";
 971                 import_file_revision(\%commit, ($fetch_from == 1), $n_actual, \%mediafile);
 972         }
 973
 974         return $n_actual;
 975 }
 976
 977 sub error_non_fast_forward {
 978         my $advice = run_git("config --bool advice.pushNonFastForward");
 979         chomp($advice);
 980         if ($advice ne "false") {
 981                 # Native git-push would show this after the summary.
 982                 # We can't ask it to display it cleanly, so print it
 983                 # ourselves before.
 984                 print STDERR "To prevent you from losing history, non-fast-forward updates were rejected\n";
 985                 print STDERR "Merge the remote changes (e.g. 'git pull') before pushing again. See the\n";
 986                 print STDERR "'Note about fast-forwards' section of 'git push --help' for details.\n";
 987         }
 988         print STDOUT "error $_[0] \"non-fast-forward\"\n";
 989         return 0;
 990 }
 991
 992 sub mw_upload_file {
 993         my $complete_file_name = shift;
 994         my $new_sha1 = shift;
 995         my $extension = shift;
 996         my $file_deleted = shift;
 997         my $summary = shift;
 998         my $newrevid;
 999         my $path = "File:" . $complete_file_name;
1000         my %hashFiles = get_allowed_file_extensions();
1001         if (!exists($hashFiles{$extension})) {
1002                 print STDERR "$complete_file_name is not a permitted file on this wiki.\n";
1003                 print STDERR "Check the configuration of file uploads in your mediawiki.\n";
1004                 return $newrevid;
1005         }
1006         # Deleting and uploading a file requires a priviledged user
1007         if ($file_deleted) {
1008                 mw_connect_maybe();
1009                 my $query = {
1010                         action => 'delete',
1011                         title => $path,
1012                         reason => $summary
1013                 };
1014                 if (!$mediawiki->edit($query)) {
1015                         print STDERR "Failed to delete file on remote wiki\n";
1016                         print STDERR "Check your permissions on the remote site. Error code:\n";
1017                         print STDERR $mediawiki->{error}->{code} . ':' . $mediawiki->{error}->{details};
1018                         exit 1;
1019                 }
1020         } else {
1021                 # Don't let perl try to interpret file content as UTF-8 => use "raw"
1022                 my $content = run_git("cat-file blob $new_sha1", "raw");
1023                 if ($content ne "") {
1024                         mw_connect_maybe();
1025                         $mediawiki->{config}->{upload_url} =
1026                                 "$url/index.php/Special:Upload";
1027                         $mediawiki->edit({
1028                                 action => 'upload',
1029                                 filename => $complete_file_name,
1030                                 comment => $summary,
1031                                 file => [undef,
1032                                          $complete_file_name,
1033                                          Content => $content],
1034                                 ignorewarnings => 1,
1035                         }, {
1036                                 skip_encoding => 1
1037                         } ) || die $mediawiki->{error}->{code} . ':'
1038                                  . $mediawiki->{error}->{details};
1039                         my $last_file_page = $mediawiki->get_page({title => $path});
1040                         $newrevid = $last_file_page->{revid};
1041                         print STDERR "Pushed file: $new_sha1 - $complete_file_name.\n";
1042                 } else {
1043                         print STDERR "Empty file $complete_file_name not pushed.\n";
1044                 }
1045         }
1046         return $newrevid;
1047 }
1048
1049 sub mw_push_file {
1050         my $diff_info = shift;
1051         # $diff_info contains a string in this format:
1052         # 100644 100644 <sha1_of_blob_before_commit> <sha1_of_blob_now> <status>
1053         my @diff_info_split = split(/[ \t]/, $diff_info);
1054
1055         # Filename, including .mw extension
1056         my $complete_file_name = shift;
1057         # Commit message
1058         my $summary = shift;
1059         # MediaWiki revision number. Keep the previous one by default,
1060         # in case there's no edit to perform.
1061         my $oldrevid = shift;
1062         my $newrevid;
1063
1064         if ($summary eq EMPTY_MESSAGE) {
1065                 $summary = '';
1066         }
1067
1068         my $new_sha1 = $diff_info_split[3];
1069         my $old_sha1 = $diff_info_split[2];
1070         my $page_created = ($old_sha1 eq NULL_SHA1);
1071         my $page_deleted = ($new_sha1 eq NULL_SHA1);
1072         $complete_file_name = mediawiki_clean_filename($complete_file_name);
1073
1074         my ($title, $extension) = $complete_file_name =~ /^(.*)\.([^\.]*)$/;
1075         if (!defined($extension)) {
1076                 $extension = "";
1077         }
1078         if ($extension eq "mw") {
1079                 my $ns = get_mw_namespace_id_for_page($complete_file_name);
1080                 if ($ns && $ns == get_mw_namespace_id("File") && (!$export_media)) {
1081                         print STDERR "Ignoring media file related page: $complete_file_name\n";
1082                         return ($oldrevid, "ok");
1083                 }
1084                 my $file_content;
1085                 if ($page_deleted) {
1086                         # Deleting a page usually requires
1087                         # special priviledges. A common
1088                         # convention is to replace the page
1089                         # with this content instead:
1090                         $file_content = DELETED_CONTENT;
1091                 } else {
1092                         $file_content = run_git("cat-file blob $new_sha1");
1093                 }
1094
1095                 mw_connect_maybe();
1096
1097                 my $result = $mediawiki->edit( {
1098                         action => 'edit',
1099                         summary => $summary,
1100                         title => $title,
1101                         basetimestamp => $basetimestamps{$oldrevid},
1102                         text => mediawiki_clean($file_content, $page_created),
1103                                   }, {
1104                                           skip_encoding => 1 # Helps with names with accentuated characters
1105                                   });
1106                 if (!$result) {
1107                         if ($mediawiki->{error}->{code} == 3) {
1108                                 # edit conflicts, considered as non-fast-forward
1109                                 print STDERR 'Warning: Error ' .
1110                                     $mediawiki->{error}->{code} .
1111                                     ' from mediwiki: ' . $mediawiki->{error}->{details} .
1112                                     ".\n";
1113                                 return ($oldrevid, "non-fast-forward");
1114                         } else {
1115                                 # Other errors. Shouldn't happen => just die()
1116                                 die 'Fatal: Error ' .
1117                                     $mediawiki->{error}->{code} .
1118                                     ' from mediwiki: ' . $mediawiki->{error}->{details};
1119                         }
1120                 }
1121                 $newrevid = $result->{edit}->{newrevid};
1122                 print STDERR "Pushed file: $new_sha1 - $title\n";
1123         } elsif ($export_media) {
1124                 $newrevid = mw_upload_file($complete_file_name, $new_sha1,
1125                                            $extension, $page_deleted,
1126                                            $summary);
1127         } else {
1128                 print STDERR "Ignoring media file $title\n";
1129         }
1130         $newrevid = ($newrevid or $oldrevid);
1131         return ($newrevid, "ok");
1132 }
1133
1134 sub mw_push {
1135         # multiple push statements can follow each other
1136         my @refsspecs = (shift, get_more_refs("push"));
1137         my $pushed;
1138         for my $refspec (@refsspecs) {
1139                 my ($force, $local, $remote) = $refspec =~ /^(\+)?([^:]*):([^:]*)$/
1140                     or die("Invalid refspec for push. Expected <src>:<dst> or +<src>:<dst>");
1141                 if ($force) {
1142                         print STDERR "Warning: forced push not allowed on a MediaWiki.\n";
1143                 }
1144                 if ($local eq "") {
1145                         print STDERR "Cannot delete remote branch on a MediaWiki\n";
1146                         print STDOUT "error $remote cannot delete\n";
1147                         next;
1148                 }
1149                 if ($remote ne "refs/heads/master") {
1150                         print STDERR "Only push to the branch 'master' is supported on a MediaWiki\n";
1151                         print STDOUT "error $remote only master allowed\n";
1152                         next;
1153                 }
1154                 if (mw_push_revision($local, $remote)) {
1155                         $pushed = 1;
1156                 }
1157         }
1158
1159         # Notify Git that the push is done
1160         print STDOUT "\n";
1161
1162         if ($pushed && $dumb_push) {
1163                 print STDERR "Just pushed some revisions to MediaWiki.\n";
1164                 print STDERR "The pushed revisions now have to be re-imported, and your current branch\n";
1165                 print STDERR "needs to be updated with these re-imported commits. You can do this with\n";
1166                 print STDERR "\n";
1167                 print STDERR "  git pull --rebase\n";
1168                 print STDERR "\n";
1169         }
1170 }
1171
1172 sub mw_push_revision {
1173         my $local = shift;
1174         my $remote = shift; # actually, this has to be "refs/heads/master" at this point.
1175         my $last_local_revid = get_last_local_revision();
1176         print STDERR ".\n"; # Finish sentence started by get_last_local_revision()
1177         my $last_remote_revid = get_last_remote_revision();
1178         my $mw_revision = $last_remote_revid;
1179
1180         # Get sha1 of commit pointed by local HEAD
1181         my $HEAD_sha1 = run_git("rev-parse $local 2>/dev/null"); chomp($HEAD_sha1);
1182         # Get sha1 of commit pointed by remotes/$remotename/master
1183         my $remoteorigin_sha1 = run_git("rev-parse refs/remotes/$remotename/master 2>/dev/null");
1184         chomp($remoteorigin_sha1);
1185
1186         if ($last_local_revid > 0 &&
1187             $last_local_revid < $last_remote_revid) {
1188                 return error_non_fast_forward($remote);
1189         }
1190
1191         if ($HEAD_sha1 eq $remoteorigin_sha1) {
1192                 # nothing to push
1193                 return 0;
1194         }
1195
1196         # Get every commit in between HEAD and refs/remotes/origin/master,
1197         # including HEAD and refs/remotes/origin/master
1198         my @commit_pairs = ();
1199         if ($last_local_revid > 0) {
1200                 my $parsed_sha1 = $remoteorigin_sha1;
1201                 # Find a path from last MediaWiki commit to pushed commit
1202                 print STDERR "Computing path from local to remote ...\n";
1203                 my @local_ancestry = split(/\n/, run_git("rev-list --boundary --parents $local ^$parsed_sha1"));
1204                 my %local_ancestry;
1205                 foreach my $line (@local_ancestry) {
1206                         if (my ($child, $parents) = $line =~ m/^-?([a-f0-9]+) ([a-f0-9 ]+)/) {
1207                                 foreach my $parent (split(' ', $parents)) {
1208                                         $local_ancestry{$parent} = $child;
1209                                 }
1210                         } elsif (!$line =~ m/^([a-f0-9]+)/) {
1211                                 die "Unexpected output from git rev-list: $line";
1212                         }
1213                 }
1214                 while ($parsed_sha1 ne $HEAD_sha1) {
1215                         my $child = $local_ancestry{$parsed_sha1};
1216                         if (!$child) {
1217                                 printf STDERR "Cannot find a path in history from remote commit to last commit\n";
1218                                 return error_non_fast_forward($remote);
1219                         }
1220                         push(@commit_pairs, [$parsed_sha1, $child]);
1221                         $parsed_sha1 = $child;
1222                 }
1223         } else {
1224                 # No remote mediawiki revision. Export the whole
1225                 # history (linearized with --first-parent)
1226                 print STDERR "Warning: no common ancestor, pushing complete history\n";
1227                 my $history = run_git("rev-list --first-parent --children $local");
1228                 my @history = split('\n', $history);
1229                 @history = @history[1..$#history];
1230                 foreach my $line (reverse @history) {
1231                         my @commit_info_split = split(/ |\n/, $line);
1232                         push(@commit_pairs, \@commit_info_split);
1233                 }
1234         }
1235
1236         foreach my $commit_info_split (@commit_pairs) {
1237                 my $sha1_child = @{$commit_info_split}[0];
1238                 my $sha1_commit = @{$commit_info_split}[1];
1239                 my $diff_infos = run_git("diff-tree -r --raw -z $sha1_child $sha1_commit");
1240                 # TODO: we could detect rename, and encode them with a #redirect on the wiki.
1241                 # TODO: for now, it's just a delete+add
1242                 my @diff_info_list = split(/\0/, $diff_infos);
1243                 # Keep the subject line of the commit message as mediawiki comment for the revision
1244                 my $commit_msg = run_git("log --no-walk --format=\"%s\" $sha1_commit");
1245                 chomp($commit_msg);
1246                 # Push every blob
1247                 while (@diff_info_list) {
1248                         my $status;
1249                         # git diff-tree -z gives an output like
1250                         # <metadata>\0<filename1>\0
1251                         # <metadata>\0<filename2>\0
1252                         # and we've split on \0.
1253                         my $info = shift(@diff_info_list);
1254                         my $file = shift(@diff_info_list);
1255                         ($mw_revision, $status) = mw_push_file($info, $file, $commit_msg, $mw_revision);
1256                         if ($status eq "non-fast-forward") {
1257                                 # we may already have sent part of the
1258                                 # commit to MediaWiki, but it's too
1259                                 # late to cancel it. Stop the push in
1260                                 # the middle, but still give an
1261                                 # accurate error message.
1262                                 return error_non_fast_forward($remote);
1263                         }
1264                         if ($status ne "ok") {
1265                                 die("Unknown error from mw_push_file()");
1266                         }
1267                 }
1268                 unless ($dumb_push) {
1269                         run_git("notes --ref=$remotename/mediawiki add -f -m \"mediawiki_revision: $mw_revision\" $sha1_commit");
1270                         run_git("update-ref -m \"Git-MediaWiki push\" refs/mediawiki/$remotename/master $sha1_commit $sha1_child");
1271                 }
1272         }
1273
1274         print STDOUT "ok $remote\n";
1275         return 1;
1276 }
1277
1278 sub get_allowed_file_extensions {
1279         mw_connect_maybe();
1280
1281         my $query = {
1282                 action => 'query',
1283                 meta => 'siteinfo',
1284                 siprop => 'fileextensions'
1285                 };
1286         my $result = $mediawiki->api($query);
1287         my @file_extensions= map $_->{ext},@{$result->{query}->{fileextensions}};
1288         my %hashFile = map {$_ => 1}@file_extensions;
1289
1290         return %hashFile;
1291 }
1292
1293 # In memory cache for MediaWiki namespace ids.
1294 my %namespace_id;
1295
1296 # Namespaces whose id is cached in the configuration file
1297 # (to avoid duplicates)
1298 my %cached_mw_namespace_id;
1299
1300 # Return MediaWiki id for a canonical namespace name.
1301 # Ex.: "File", "Project".
1302 sub get_mw_namespace_id {
1303         mw_connect_maybe();
1304         my $name = shift;
1305
1306         if (!exists $namespace_id{$name}) {
1307                 # Look at configuration file, if the record for that namespace is
1308                 # already cached. Namespaces are stored in form:
1309                 # "Name_of_namespace:Id_namespace", ex.: "File:6".
1310                 my @temp = split(/[\n]/, run_git("config --get-all remote."
1311                                                 . $remotename .".namespaceCache"));
1312                 chomp(@temp);
1313                 foreach my $ns (@temp) {
1314                         my ($n, $id) = split(/:/, $ns);
1315                         $namespace_id{$n} = $id;
1316                         $cached_mw_namespace_id{$n} = 1;
1317                 }
1318         }
1319
1320         if (!exists $namespace_id{$name}) {
1321                 print STDERR "Namespace $name not found in cache, querying the wiki ...\n";
1322                 # NS not found => get namespace id from MW and store it in
1323                 # configuration file.
1324                 my $query = {
1325                         action => 'query',
1326                         meta => 'siteinfo',
1327                         siprop => 'namespaces'
1328                 };
1329                 my $result = $mediawiki->api($query);
1330
1331                 while (my ($id, $ns) = each(%{$result->{query}->{namespaces}})) {
1332                         if (defined($ns->{id}) && defined($ns->{canonical})) {
1333                                 $namespace_id{$ns->{canonical}} = $ns->{id};
1334                                 if ($ns->{'*'}) {
1335                                         # alias (e.g. french Fichier: as alias for canonical File:)
1336                                         $namespace_id{$ns->{'*'}} = $ns->{id};
1337                                 }
1338                         }
1339                 }
1340         }
1341
1342         my $id = $namespace_id{$name};
1343
1344         if (defined $id) {
1345                 # Store explicitely requested namespaces on disk
1346                 if (!exists $cached_mw_namespace_id{$name}) {
1347                         run_git("config --add remote.". $remotename
1348                                 .".namespaceCache \"". $name .":". $id ."\"");
1349                         $cached_mw_namespace_id{$name} = 1;
1350                 }
1351                 return $id;
1352         } else {
1353                 die "No such namespace $name on MediaWiki.";
1354         }
1355 }
1356
1357 sub get_mw_namespace_id_for_page {
1358         if (my ($namespace) = $_[0] =~ /^([^:]*):/) {
1359                 return get_mw_namespace_id($namespace);
1360         } else {
1361                 return;
1362         }
1363 }