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

   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 # Documentation & bugtracker: https://github.com/moy/Git-Mediawiki/
  13
  14 use strict;
  15 use MediaWiki::API;
  16 use DateTime::Format::ISO8601;
  17
  18 # By default, use UTF-8 to communicate with Git and the user
  19 binmode STDERR, ":utf8";
  20 binmode STDOUT, ":utf8";
  21
  22 use URI::Escape;
  23 use IPC::Open2;
  24
  25 use warnings;
  26
  27 # Mediawiki filenames can contain forward slashes. This variable decides by which pattern they should be replaced
  28 use constant SLASH_REPLACEMENT => "%2F";
  29
  30 # It's not always possible to delete pages (may require some
  31 # privileges). Deleted pages are replaced with this content.
  32 use constant DELETED_CONTENT => "[[Category:Deleted]]\n";
  33
  34 # It's not possible to create empty pages. New empty files in Git are
  35 # sent with this content instead.
  36 use constant EMPTY_CONTENT => "<!-- empty page -->\n";
  37
  38 # used to reflect file creation or deletion in diff.
  39 use constant NULL_SHA1 => "0000000000000000000000000000000000000000";
  40
  41 # Used on Git's side to reflect empty edit messages on the wiki
  42 use constant EMPTY_MESSAGE => '*Empty MediaWiki Message*';
  43
  44 my $remotename = $ARGV[0];
  45 my $url = $ARGV[1];
  46
  47 # Accept both space-separated and multiple keys in config file.
  48 # Spaces should be written as _ anyway because we'll use chomp.
  49 my @tracked_pages = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".pages"));
  50 chomp(@tracked_pages);
  51
  52 # Just like @tracked_pages, but for MediaWiki categories.
  53 my @tracked_categories = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".categories"));
  54 chomp(@tracked_categories);
  55
  56 # Import media files on pull
  57 my $import_media = run_git("config --get --bool remote.". $remotename .".mediaimport");
  58 chomp($import_media);
  59 $import_media = ($import_media eq "true");
  60
  61 # Export media files on push
  62 my $export_media = run_git("config --get --bool remote.". $remotename .".mediaexport");
  63 chomp($export_media);
  64 $export_media = !($export_media eq "false");
  65
  66 my $wiki_login = run_git("config --get remote.". $remotename .".mwLogin");
  67 # Note: mwPassword is discourraged. Use the credential system instead.
  68 my $wiki_passwd = run_git("config --get remote.". $remotename .".mwPassword");
  69 my $wiki_domain = run_git("config --get remote.". $remotename .".mwDomain");
  70 chomp($wiki_login);
  71 chomp($wiki_passwd);
  72 chomp($wiki_domain);
  73
  74 # Import only last revisions (both for clone and fetch)
  75 my $shallow_import = run_git("config --get --bool remote.". $remotename .".shallow");
  76 chomp($shallow_import);
  77 $shallow_import = ($shallow_import eq "true");
  78
  79 # Fetch (clone and pull) by revisions instead of by pages. This behavior
  80 # is more efficient when we have a wiki with lots of pages and we fetch
  81 # the revisions quite often so that they concern only few pages.
  82 # Possible values:
  83 # - by_rev: perform one query per new revision on the remote wiki
  84 # - by_page: query each tracked page for new revision
  85 my $fetch_strategy = run_git("config --get remote.$remotename.fetchStrategy");
  86 unless ($fetch_strategy) {
  87         $fetch_strategy = run_git("config --get mediawiki.fetchStrategy");
  88 }
  89 chomp($fetch_strategy);
  90 unless ($fetch_strategy) {
  91         $fetch_strategy = "by_page";
  92 }
  93
  94 # Dumb push: don't update notes and mediawiki ref to reflect the last push.
  95 #
  96 # Configurable with mediawiki.dumbPush, or per-remote with
  97 # remote.<remotename>.dumbPush.
  98 #
  99 # This means the user will have to re-import the just-pushed
 100 # revisions. On the other hand, this means that the Git revisions
 101 # corresponding to MediaWiki revisions are all imported from the wiki,
 102 # regardless of whether they were initially created in Git or from the
 103 # web interface, hence all users will get the same history (i.e. if
 104 # the push from Git to MediaWiki loses some information, everybody
 105 # will get the history with information lost). If the import is
 106 # deterministic, this means everybody gets the same sha1 for each
 107 # MediaWiki revision.
 108 my $dumb_push = run_git("config --get --bool remote.$remotename.dumbPush");
 109 unless ($dumb_push) {
 110         $dumb_push = run_git("config --get --bool mediawiki.dumbPush");
 111 }
 112 chomp($dumb_push);
 113 $dumb_push = ($dumb_push eq "true");
 114
 115 my $wiki_name = $url;
 116 $wiki_name =~ s/[^\/]*:\/\///;
 117 # If URL is like http://user:password@example.com/, we clearly don't
 118 # want the password in $wiki_name. While we're there, also remove user
 119 # and '@' sign, to avoid author like MWUser@HTTPUser@host.com
 120 $wiki_name =~ s/^.*@//;
 121
 122 # Commands parser
 123 my $entry;
 124 my @cmd;
 125 while (<STDIN>) {
 126         chomp;
 127         @cmd = split(/ /);
 128         if (defined($cmd[0])) {
 129                 # Line not blank
 130                 if ($cmd[0] eq "capabilities") {
 131                         die("Too many arguments for capabilities") unless (!defined($cmd[1]));
 132                         mw_capabilities();
 133                 } elsif ($cmd[0] eq "list") {
 134                         die("Too many arguments for list") unless (!defined($cmd[2]));
 135                         mw_list($cmd[1]);
 136                 } elsif ($cmd[0] eq "import") {
 137                         die("Invalid arguments for import") unless ($cmd[1] ne "" && !defined($cmd[2]));
 138                         mw_import($cmd[1]);
 139                 } elsif ($cmd[0] eq "option") {
 140                         die("Too many arguments for option") unless ($cmd[1] ne "" && $cmd[2] ne "" && !defined($cmd[3]));
 141                         mw_option($cmd[1],$cmd[2]);
 142                 } elsif ($cmd[0] eq "push") {
 143                         mw_push($cmd[1]);
 144                 } else {
 145                         print STDERR "Unknown command. Aborting...\n";
 146                         last;
 147                 }
 148         } else {
 149                 # blank line: we should terminate
 150                 last;
 151         }
 152
 153         BEGIN { $| = 1 } # flush STDOUT, to make sure the previous
 154                          # command is fully processed.
 155 }
 156
 157 ########################## Functions ##############################
 158
 159 ## credential API management (generic functions)
 160
 161 sub credential_read {
 162         my %credential;
 163         my $reader = shift;
 164         my $op = shift;
 165         while (<$reader>) {
 166                 my ($key, $value) = /([^=]*)=(.*)/;
 167                 if (not defined $key) {
 168                         die "ERROR receiving response from git credential $op:\n$_\n";
 169                 }
 170                 $credential{$key} = $value;
 171         }
 172         return %credential;
 173 }
 174
 175 sub credential_write {
 176         my $credential = shift;
 177         my $writer = shift;
 178         # url overwrites other fields, so it must come first
 179         print $writer "url=$credential->{url}\n" if exists $credential->{url};
 180         while (my ($key, $value) = each(%$credential) ) {
 181                 if (length $value && $key ne 'url') {
 182                         print $writer "$key=$value\n";
 183                 }
 184         }
 185 }
 186
 187 sub credential_run {
 188         my $op = shift;
 189         my $credential = shift;
 190         my $pid = open2(my $reader, my $writer, "git credential $op");
 191         credential_write($credential, $writer);
 192         print $writer "\n";
 193         close($writer);
 194
 195         if ($op eq "fill") {
 196                 %$credential = credential_read($reader, $op);
 197         } else {
 198                 if (<$reader>) {
 199                         die "ERROR while running git credential $op:\n$_";
 200                 }
 201         }
 202         close($reader);
 203         waitpid($pid, 0);
 204         my $child_exit_status = $? >> 8;
 205         if ($child_exit_status != 0) {
 206                 die "'git credential $op' failed with code $child_exit_status.";
 207         }
 208 }
 209
 210 # MediaWiki API instance, created lazily.
 211 my $mediawiki;
 212
 213 sub mw_connect_maybe {
 214         if ($mediawiki) {
 215                 return;
 216         }
 217         $mediawiki = MediaWiki::API->new;
 218         $mediawiki->{config}->{api_url} = "$url/api.php";
 219         if ($wiki_login) {
 220                 my %credential = (url => $url);
 221                 $credential{username} = $wiki_login;
 222                 $credential{password} = $wiki_passwd;
 223                 credential_run("fill", \%credential);
 224                 my $request = {lgname => $credential{username},
 225                                lgpassword => $credential{password},
 226                                lgdomain => $wiki_domain};
 227                 if ($mediawiki->login($request)) {
 228                         credential_run("approve", \%credential);
 229                         print STDERR "Logged in mediawiki user \"$credential{username}\".\n";
 230                 } else {
 231                         print STDERR "Failed to log in mediawiki user \"$credential{username}\" on $url\n";
 232                         print STDERR "  (error " .
 233                                 $mediawiki->{error}->{code} . ': ' .
 234                                 $mediawiki->{error}->{details} . ")\n";
 235                         credential_run("reject", \%credential);
 236                         exit 1;
 237                 }
 238         }
 239 }
 240
 241 sub fatal_mw_error {
 242         my $action = shift;
 243         print STDERR "fatal: could not $action.\n";
 244         print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 245         if ($url =~ /^https/) {
 246                 print STDERR "fatal: make sure '$url/api.php' is a valid page\n";
 247                 print STDERR "fatal: and the SSL certificate is correct.\n";
 248         } else {
 249                 print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 250         }
 251         print STDERR "fatal: (error " .
 252             $mediawiki->{error}->{code} . ': ' .
 253             $mediawiki->{error}->{details} . ")\n";
 254         exit 1;
 255 }
 256
 257 ## Functions for listing pages on the remote wiki
 258 sub get_mw_tracked_pages {
 259         my $pages = shift;
 260         get_mw_page_list(\@tracked_pages, $pages);
 261 }
 262
 263 sub get_mw_page_list {
 264         my $page_list = shift;
 265         my $pages = shift;
 266         my @some_pages = @$page_list;
 267         while (@some_pages) {
 268                 my $last = 50;
 269                 if ($#some_pages < $last) {
 270                         $last = $#some_pages;
 271                 }
 272                 my @slice = @some_pages[0..$last];
 273                 get_mw_first_pages(\@slice, $pages);
 274                 @some_pages = @some_pages[51..$#some_pages];
 275         }
 276 }
 277
 278 sub get_mw_tracked_categories {
 279         my $pages = shift;
 280         foreach my $category (@tracked_categories) {
 281                 if (index($category, ':') < 0) {
 282                         # Mediawiki requires the Category
 283                         # prefix, but let's not force the user
 284                         # to specify it.
 285                         $category = "Category:" . $category;
 286                 }
 287                 my $mw_pages = $mediawiki->list( {
 288                         action => 'query',
 289                         list => 'categorymembers',
 290                         cmtitle => $category,
 291                         cmlimit => 'max' } )
 292                         || die $mediawiki->{error}->{code} . ': '
 293                                 . $mediawiki->{error}->{details};
 294                 foreach my $page (@{$mw_pages}) {
 295                         $pages->{$page->{title}} = $page;
 296                 }
 297         }
 298 }
 299
 300 sub get_mw_all_pages {
 301         my $pages = shift;
 302         # No user-provided list, get the list of pages from the API.
 303         my $mw_pages = $mediawiki->list({
 304                 action => 'query',
 305                 list => 'allpages',
 306                 aplimit => 'max'
 307         });
 308         if (!defined($mw_pages)) {
 309                 fatal_mw_error("get the list of wiki pages");
 310         }
 311         foreach my $page (@{$mw_pages}) {
 312                 $pages->{$page->{title}} = $page;
 313         }
 314 }
 315
 316 # queries the wiki for a set of pages. Meant to be used within a loop
 317 # querying the wiki for slices of page list.
 318 sub get_mw_first_pages {
 319         my $some_pages = shift;
 320         my @some_pages = @{$some_pages};
 321
 322         my $pages = shift;
 323
 324         # pattern 'page1|page2|...' required by the API
 325         my $titles = join('|', @some_pages);
 326
 327         my $mw_pages = $mediawiki->api({
 328                 action => 'query',
 329                 titles => $titles,
 330         });
 331         if (!defined($mw_pages)) {
 332                 fatal_mw_error("query the list of wiki pages");
 333         }
 334         while (my ($id, $page) = each(%{$mw_pages->{query}->{pages}})) {
 335                 if ($id < 0) {
 336                         print STDERR "Warning: page $page->{title} not found on wiki\n";
 337                 } else {
 338                         $pages->{$page->{title}} = $page;
 339                 }
 340         }
 341 }
 342
 343 # Get the list of pages to be fetched according to configuration.
 344 sub get_mw_pages {
 345         mw_connect_maybe();
 346
 347         print STDERR "Listing pages on remote wiki...\n";
 348
 349         my %pages; # hash on page titles to avoid duplicates
 350         my $user_defined;
 351         if (@tracked_pages) {
 352                 $user_defined = 1;
 353                 # The user provided a list of pages titles, but we
 354                 # still need to query the API to get the page IDs.
 355                 get_mw_tracked_pages(\%pages);
 356         }
 357         if (@tracked_categories) {
 358                 $user_defined = 1;
 359                 get_mw_tracked_categories(\%pages);
 360         }
 361         if (!$user_defined) {
 362                 get_mw_all_pages(\%pages);
 363         }
 364         if ($import_media) {
 365                 print STDERR "Getting media files for selected pages...\n";
 366                 if ($user_defined) {
 367                         get_linked_mediafiles(\%pages);
 368                 } else {
 369                         get_all_mediafiles(\%pages);
 370                 }
 371         }
 372         print STDERR (scalar keys %pages) . " pages found.\n";
 373         return %pages;
 374 }
 375
 376 # usage: $out = run_git("command args");
 377 #        $out = run_git("command args", "raw"); # don't interpret output as UTF-8.
 378 sub run_git {
 379         my $args = shift;
 380         my $encoding = (shift || "encoding(UTF-8)");
 381         open(my $git, "-|:$encoding", "git " . $args);
 382         my $res = do { local $/; <$git> };
 383         close($git);
 384
 385         return $res;
 386 }
 387
 388
 389 sub get_all_mediafiles {
 390         my $pages = shift;
 391         # Attach list of all pages for media files from the API,
 392         # they are in a different namespace, only one namespace
 393         # can be queried at the same moment
 394         my $mw_pages = $mediawiki->list({
 395                 action => 'query',
 396                 list => 'allpages',
 397                 apnamespace => get_mw_namespace_id("File"),
 398                 aplimit => 'max'
 399         });
 400         if (!defined($mw_pages)) {
 401                 print STDERR "fatal: could not get the list of pages for media files.\n";
 402                 print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 403                 print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 404                 exit 1;
 405         }
 406         foreach my $page (@{$mw_pages}) {
 407                 $pages->{$page->{title}} = $page;
 408         }
 409 }
 410
 411 sub get_linked_mediafiles {
 412         my $pages = shift;
 413         my @titles = map $_->{title}, values(%{$pages});
 414
 415         # The query is split in small batches because of the MW API limit of
 416         # the number of links to be returned (500 links max).
 417         my $batch = 10;
 418         while (@titles) {
 419                 if ($#titles < $batch) {
 420                         $batch = $#titles;
 421                 }
 422                 my @slice = @titles[0..$batch];
 423
 424                 # pattern 'page1|page2|...' required by the API
 425                 my $mw_titles = join('|', @slice);
 426
 427                 # Media files could be included or linked from
 428                 # a page, get all related
 429                 my $query = {
 430                         action => 'query',
 431                         prop => 'links|images',
 432                         titles => $mw_titles,
 433                         plnamespace => get_mw_namespace_id("File"),
 434                         pllimit => 'max'
 435                 };
 436                 my $result = $mediawiki->api($query);
 437
 438                 while (my ($id, $page) = each(%{$result->{query}->{pages}})) {
 439                         my @media_titles;
 440                         if (defined($page->{links})) {
 441                                 my @link_titles = map $_->{title}, @{$page->{links}};
 442                                 push(@media_titles, @link_titles);
 443                         }
 444                         if (defined($page->{images})) {
 445                                 my @image_titles = map $_->{title}, @{$page->{images}};
 446                                 push(@media_titles, @image_titles);
 447                         }
 448                         if (@media_titles) {
 449                                 get_mw_page_list(\@media_titles, $pages);
 450                         }
 451                 }
 452
 453                 @titles = @titles[($batch+1)..$#titles];
 454         }
 455 }
 456
 457 sub get_mw_mediafile_for_page_revision {
 458         # Name of the file on Wiki, with the prefix.
 459         my $filename = shift;
 460         my $timestamp = shift;
 461         my %mediafile;
 462
 463         # Search if on a media file with given timestamp exists on
 464         # MediaWiki. In that case download the file.
 465         my $query = {
 466                 action => 'query',
 467                 prop => 'imageinfo',
 468                 titles => "File:" . $filename,
 469                 iistart => $timestamp,
 470                 iiend => $timestamp,
 471                 iiprop => 'timestamp|archivename|url',
 472                 iilimit => 1
 473         };
 474         my $result = $mediawiki->api($query);
 475
 476         my ($fileid, $file) = each( %{$result->{query}->{pages}} );
 477         # If not defined it means there is no revision of the file for
 478         # given timestamp.
 479         if (defined($file->{imageinfo})) {
 480                 $mediafile{title} = $filename;
 481
 482                 my $fileinfo = pop(@{$file->{imageinfo}});
 483                 $mediafile{timestamp} = $fileinfo->{timestamp};
 484                 # Mediawiki::API's download function doesn't support https URLs
 485                 # and can't download old versions of files.
 486                 print STDERR "\tDownloading file $mediafile{title}, version $mediafile{timestamp}\n";
 487                 $mediafile{content} = download_mw_mediafile($fileinfo->{url});
 488         }
 489         return %mediafile;
 490 }
 491
 492 sub download_mw_mediafile {
 493         my $url = shift;
 494
 495         my $response = $mediawiki->{ua}->get($url);
 496         if ($response->code == 200) {
 497                 return $response->decoded_content;
 498         } else {
 499                 print STDERR "Error downloading mediafile from :\n";
 500                 print STDERR "URL: $url\n";
 501                 print STDERR "Server response: " . $response->code . " " . $response->message . "\n";
 502                 exit 1;
 503         }
 504 }
 505
 506 sub get_last_local_revision {
 507         # Get note regarding last mediawiki revision
 508         my $note = run_git("notes --ref=$remotename/mediawiki show refs/mediawiki/$remotename/master 2>/dev/null");
 509         my @note_info = split(/ /, $note);
 510
 511         my $lastrevision_number;
 512         if (!(defined($note_info[0]) && $note_info[0] eq "mediawiki_revision:")) {
 513                 print STDERR "No previous mediawiki revision found";
 514                 $lastrevision_number = 0;
 515         } else {
 516                 # Notes are formatted : mediawiki_revision: #number
 517                 $lastrevision_number = $note_info[1];
 518                 chomp($lastrevision_number);
 519                 print STDERR "Last local mediawiki revision found is $lastrevision_number";
 520         }
 521         return $lastrevision_number;
 522 }
 523
 524 # Remember the timestamp corresponding to a revision id.
 525 my %basetimestamps;
 526
 527 # Get the last remote revision without taking in account which pages are
 528 # tracked or not. This function makes a single request to the wiki thus
 529 # avoid a loop onto all tracked pages. This is useful for the fetch-by-rev
 530 # option.
 531 sub get_last_global_remote_rev {
 532         mw_connect_maybe();
 533
 534         my $query = {
 535                 action => 'query',
 536                 list => 'recentchanges',
 537                 prop => 'revisions',
 538                 rclimit => '1',
 539                 rcdir => 'older',
 540         };
 541         my $result = $mediawiki->api($query);
 542         return $result->{query}->{recentchanges}[0]->{revid};
 543 }
 544
 545 # Get the last remote revision concerning the tracked pages and the tracked
 546 # categories.
 547 sub get_last_remote_revision {
 548         mw_connect_maybe();
 549
 550         my %pages_hash = get_mw_pages();
 551         my @pages = values(%pages_hash);
 552
 553         my $max_rev_num = 0;
 554
 555         print STDERR "Getting last revision id on tracked pages...\n";
 556
 557         foreach my $page (@pages) {
 558                 my $id = $page->{pageid};
 559
 560                 my $query = {
 561                         action => 'query',
 562                         prop => 'revisions',
 563                         rvprop => 'ids|timestamp',
 564                         pageids => $id,
 565                 };
 566
 567                 my $result = $mediawiki->api($query);
 568
 569                 my $lastrev = pop(@{$result->{query}->{pages}->{$id}->{revisions}});
 570
 571                 $basetimestamps{$lastrev->{revid}} = $lastrev->{timestamp};
 572
 573                 $max_rev_num = ($lastrev->{revid} > $max_rev_num ? $lastrev->{revid} : $max_rev_num);
 574         }
 575
 576         print STDERR "Last remote revision found is $max_rev_num.\n";
 577         return $max_rev_num;
 578 }
 579
 580 # Clean content before sending it to MediaWiki
 581 sub mediawiki_clean {
 582         my $string = shift;
 583         my $page_created = shift;
 584         # Mediawiki does not allow blank space at the end of a page and ends with a single \n.
 585         # This function right trims a string and adds a \n at the end to follow this rule
 586         $string =~ s/\s+$//;
 587         if ($string eq "" && $page_created) {
 588                 # Creating empty pages is forbidden.
 589                 $string = EMPTY_CONTENT;
 590         }
 591         return $string."\n";
 592 }
 593
 594 # Filter applied on MediaWiki data before adding them to Git
 595 sub mediawiki_smudge {
 596         my $string = shift;
 597         if ($string eq EMPTY_CONTENT) {
 598                 $string = "";
 599         }
 600         # This \n is important. This is due to mediawiki's way to handle end of files.
 601         return $string."\n";
 602 }
 603
 604 sub mediawiki_clean_filename {
 605         my $filename = shift;
 606         $filename =~ s/@{[SLASH_REPLACEMENT]}/\//g;
 607         # [, ], |, {, and } are forbidden by MediaWiki, even URL-encoded.
 608         # Do a variant of URL-encoding, i.e. looks like URL-encoding,
 609         # but with _ added to prevent MediaWiki from thinking this is
 610         # an actual special character.
 611         $filename =~ s/[\[\]\{\}\|]/sprintf("_%%_%x", ord($&))/ge;
 612         # If we use the uri escape before
 613         # we should unescape here, before anything
 614
 615         return $filename;
 616 }
 617
 618 sub mediawiki_smudge_filename {
 619         my $filename = shift;
 620         $filename =~ s/\//@{[SLASH_REPLACEMENT]}/g;
 621         $filename =~ s/ /_/g;
 622         # Decode forbidden characters encoded in mediawiki_clean_filename
 623         $filename =~ s/_%_([0-9a-fA-F][0-9a-fA-F])/sprintf("%c", hex($1))/ge;
 624         return $filename;
 625 }
 626
 627 sub literal_data {
 628         my ($content) = @_;
 629         print STDOUT "data ", bytes::length($content), "\n", $content;
 630 }
 631
 632 sub literal_data_raw {
 633         # Output possibly binary content.
 634         my ($content) = @_;
 635         # Avoid confusion between size in bytes and in characters
 636         utf8::downgrade($content);
 637         binmode STDOUT, ":raw";
 638         print STDOUT "data ", bytes::length($content), "\n", $content;
 639         binmode STDOUT, ":utf8";
 640 }
 641
 642 sub mw_capabilities {
 643         # Revisions are imported to the private namespace
 644         # refs/mediawiki/$remotename/ by the helper and fetched into
 645         # refs/remotes/$remotename later by fetch.
 646         print STDOUT "refspec refs/heads/*:refs/mediawiki/$remotename/*\n";
 647         print STDOUT "import\n";
 648         print STDOUT "list\n";
 649         print STDOUT "push\n";
 650         print STDOUT "\n";
 651 }
 652
 653 sub mw_list {
 654         # MediaWiki do not have branches, we consider one branch arbitrarily
 655         # called master, and HEAD pointing to it.
 656         print STDOUT "? refs/heads/master\n";
 657         print STDOUT "\@refs/heads/master HEAD\n";
 658         print STDOUT "\n";
 659 }
 660
 661 sub mw_option {
 662         print STDERR "remote-helper command 'option $_[0]' not yet implemented\n";
 663         print STDOUT "unsupported\n";
 664 }
 665
 666 sub fetch_mw_revisions_for_page {
 667         my $page = shift;
 668         my $id = shift;
 669         my $fetch_from = shift;
 670         my @page_revs = ();
 671         my $query = {
 672                 action => 'query',
 673                 prop => 'revisions',
 674                 rvprop => 'ids',
 675                 rvdir => 'newer',
 676                 rvstartid => $fetch_from,
 677                 rvlimit => 500,
 678                 pageids => $id,
 679         };
 680
 681         my $revnum = 0;
 682         # Get 500 revisions at a time due to the mediawiki api limit
 683         while (1) {
 684                 my $result = $mediawiki->api($query);
 685
 686                 # Parse each of those 500 revisions
 687                 foreach my $revision (@{$result->{query}->{pages}->{$id}->{revisions}}) {
 688                         my $page_rev_ids;
 689                         $page_rev_ids->{pageid} = $page->{pageid};
 690                         $page_rev_ids->{revid} = $revision->{revid};
 691                         push(@page_revs, $page_rev_ids);
 692                         $revnum++;
 693                 }
 694                 last unless $result->{'query-continue'};
 695                 $query->{rvstartid} = $result->{'query-continue'}->{revisions}->{rvstartid};
 696         }
 697         if ($shallow_import && @page_revs) {
 698                 print STDERR "  Found 1 revision (shallow import).\n";
 699                 @page_revs = sort {$b->{revid} <=> $a->{revid}} (@page_revs);
 700                 return $page_revs[0];
 701         }
 702         print STDERR "  Found ", $revnum, " revision(s).\n";
 703         return @page_revs;
 704 }
 705
 706 sub fetch_mw_revisions {
 707         my $pages = shift; my @pages = @{$pages};
 708         my $fetch_from = shift;
 709
 710         my @revisions = ();
 711         my $n = 1;
 712         foreach my $page (@pages) {
 713                 my $id = $page->{pageid};
 714
 715                 print STDERR "page $n/", scalar(@pages), ": ". $page->{title} ."\n";
 716                 $n++;
 717                 my @page_revs = fetch_mw_revisions_for_page($page, $id, $fetch_from);
 718                 @revisions = (@page_revs, @revisions);
 719         }
 720
 721         return ($n, @revisions);
 722 }
 723
 724 sub fe_escape_path {
 725     my $path = shift;
 726     $path =~ s/\\/\\\\/g;
 727     $path =~ s/"/\\"/g;
 728     $path =~ s/\n/\\n/g;
 729     return '"' . $path . '"';
 730 }
 731
 732 sub import_file_revision {
 733         my $commit = shift;
 734         my %commit = %{$commit};
 735         my $full_import = shift;
 736         my $n = shift;
 737         my $mediafile = shift;
 738         my %mediafile;
 739         if ($mediafile) {
 740                 %mediafile = %{$mediafile};
 741         }
 742
 743         my $title = $commit{title};
 744         my $comment = $commit{comment};
 745         my $content = $commit{content};
 746         my $author = $commit{author};
 747         my $date = $commit{date};
 748
 749         print STDOUT "commit refs/mediawiki/$remotename/master\n";
 750         print STDOUT "mark :$n\n";
 751         print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 752         literal_data($comment);
 753
 754         # If it's not a clone, we need to know where to start from
 755         if (!$full_import && $n == 1) {
 756                 print STDOUT "from refs/mediawiki/$remotename/master^0\n";
 757         }
 758         if ($content ne DELETED_CONTENT) {
 759                 print STDOUT "M 644 inline " .
 760                     fe_escape_path($title . ".mw") . "\n";
 761                 literal_data($content);
 762                 if (%mediafile) {
 763                         print STDOUT "M 644 inline "
 764                             . fe_escape_path($mediafile{title}) . "\n";
 765                         literal_data_raw($mediafile{content});
 766                 }
 767                 print STDOUT "\n\n";
 768         } else {
 769                 print STDOUT "D " . fe_escape_path($title . ".mw") . "\n";
 770         }
 771
 772         # mediawiki revision number in the git note
 773         if ($full_import && $n == 1) {
 774                 print STDOUT "reset refs/notes/$remotename/mediawiki\n";
 775         }
 776         print STDOUT "commit refs/notes/$remotename/mediawiki\n";
 777         print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 778         literal_data("Note added by git-mediawiki during import");
 779         if (!$full_import && $n == 1) {
 780                 print STDOUT "from refs/notes/$remotename/mediawiki^0\n";
 781         }
 782         print STDOUT "N inline :$n\n";
 783         literal_data("mediawiki_revision: " . $commit{mw_revision});
 784         print STDOUT "\n\n";
 785 }
 786
 787 # parse a sequence of
 788 # <cmd> <arg1>
 789 # <cmd> <arg2>
 790 # \n
 791 # (like batch sequence of import and sequence of push statements)
 792 sub get_more_refs {
 793         my $cmd = shift;
 794         my @refs;
 795         while (1) {
 796                 my $line = <STDIN>;
 797                 if ($line =~ m/^$cmd (.*)$/) {
 798                         push(@refs, $1);
 799                 } elsif ($line eq "\n") {
 800                         return @refs;
 801                 } else {
 802                         die("Invalid command in a '$cmd' batch: ". $_);
 803                 }
 804         }
 805 }
 806
 807 sub mw_import {
 808         # multiple import commands can follow each other.
 809         my @refs = (shift, get_more_refs("import"));
 810         foreach my $ref (@refs) {
 811                 mw_import_ref($ref);
 812         }
 813         print STDOUT "done\n";
 814 }
 815
 816 sub mw_import_ref {
 817         my $ref = shift;
 818         # The remote helper will call "import HEAD" and
 819         # "import refs/heads/master".
 820         # Since HEAD is a symbolic ref to master (by convention,
 821         # followed by the output of the command "list" that we gave),
 822         # we don't need to do anything in this case.
 823         if ($ref eq "HEAD") {
 824                 return;
 825         }
 826
 827         mw_connect_maybe();
 828
 829         print STDERR "Searching revisions...\n";
 830         my $last_local = get_last_local_revision();
 831         my $fetch_from = $last_local + 1;
 832         if ($fetch_from == 1) {
 833                 print STDERR ", fetching from beginning.\n";
 834         } else {
 835                 print STDERR ", fetching from here.\n";
 836         }
 837
 838         my $n = 0;
 839         if ($fetch_strategy eq "by_rev") {
 840                 print STDERR "Fetching & writing export data by revs...\n";
 841                 $n = mw_import_ref_by_revs($fetch_from);
 842         } elsif ($fetch_strategy eq "by_page") {
 843                 print STDERR "Fetching & writing export data by pages...\n";
 844                 $n = mw_import_ref_by_pages($fetch_from);
 845         } else {
 846                 print STDERR "fatal: invalid fetch strategy \"$fetch_strategy\".\n";
 847                 print STDERR "Check your configuration variables remote.$remotename.fetchStrategy and mediawiki.fetchStrategy\n";
 848                 exit 1;
 849         }
 850
 851         if ($fetch_from == 1 && $n == 0) {
 852                 print STDERR "You appear to have cloned an empty MediaWiki.\n";
 853                 # Something has to be done remote-helper side. If nothing is done, an error is
 854                 # thrown saying that HEAD is referring to unknown object 0000000000000000000
 855                 # and the clone fails.
 856         }
 857 }
 858
 859 sub mw_import_ref_by_pages {
 860
 861         my $fetch_from = shift;
 862         my %pages_hash = get_mw_pages();
 863         my @pages = values(%pages_hash);
 864
 865         my ($n, @revisions) = fetch_mw_revisions(\@pages, $fetch_from);
 866
 867         @revisions = sort {$a->{revid} <=> $b->{revid}} @revisions;
 868         my @revision_ids = map $_->{revid}, @revisions;
 869
 870         return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 871 }
 872
 873 sub mw_import_ref_by_revs {
 874
 875         my $fetch_from = shift;
 876         my %pages_hash = get_mw_pages();
 877
 878         my $last_remote = get_last_global_remote_rev();
 879         my @revision_ids = $fetch_from..$last_remote;
 880         return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 881 }
 882
 883 # Import revisions given in second argument (array of integers).
 884 # Only pages appearing in the third argument (hash indexed by page titles)
 885 # will be imported.
 886 sub mw_import_revids {
 887         my $fetch_from = shift;
 888         my $revision_ids = shift;
 889         my $pages = shift;
 890
 891         my $n = 0;
 892         my $n_actual = 0;
 893         my $last_timestamp = 0; # Placeholer in case $rev->timestamp is undefined
 894
 895         foreach my $pagerevid (@$revision_ids) {
 896                 # Count page even if we skip it, since we display
 897                 # $n/$total and $total includes skipped pages.
 898                 $n++;
 899
 900                 # fetch the content of the pages
 901                 my $query = {
 902                         action => 'query',
 903                         prop => 'revisions',
 904                         rvprop => 'content|timestamp|comment|user|ids',
 905                         revids => $pagerevid,
 906                 };
 907
 908                 my $result = $mediawiki->api($query);
 909
 910                 if (!$result) {
 911                         die "Failed to retrieve modified page for revision $pagerevid";
 912                 }
 913
 914                 if (defined($result->{query}->{badrevids}->{$pagerevid})) {
 915                         # The revision id does not exist on the remote wiki.
 916                         next;
 917                 }
 918
 919                 if (!defined($result->{query}->{pages})) {
 920                         die "Invalid revision $pagerevid.";
 921                 }
 922
 923                 my @result_pages = values(%{$result->{query}->{pages}});
 924                 my $result_page = $result_pages[0];
 925                 my $rev = $result_pages[0]->{revisions}->[0];
 926
 927                 my $page_title = $result_page->{title};
 928
 929                 if (!exists($pages->{$page_title})) {
 930                         print STDERR "$n/", scalar(@$revision_ids),
 931                                 ": Skipping revision #$rev->{revid} of $page_title\n";
 932                         next;
 933                 }
 934
 935                 $n_actual++;
 936
 937                 my %commit;
 938                 $commit{author} = $rev->{user} || 'Anonymous';
 939                 $commit{comment} = $rev->{comment} || EMPTY_MESSAGE;
 940                 $commit{title} = mediawiki_smudge_filename($page_title);
 941                 $commit{mw_revision} = $rev->{revid};
 942                 $commit{content} = mediawiki_smudge($rev->{'*'});
 943
 944                 if (!defined($rev->{timestamp})) {
 945                         $last_timestamp++;
 946                 } else {
 947                         $last_timestamp = $rev->{timestamp};
 948                 }
 949                 $commit{date} = DateTime::Format::ISO8601->parse_datetime($last_timestamp);
 950
 951                 # Differentiates classic pages and media files.
 952                 my ($namespace, $filename) = $page_title =~ /^([^:]*):(.*)$/;
 953                 my %mediafile;
 954                 if ($namespace) {
 955                         my $id = get_mw_namespace_id($namespace);
 956                         if ($id && $id == get_mw_namespace_id("File")) {
 957                                 %mediafile = get_mw_mediafile_for_page_revision($filename, $rev->{timestamp});
 958                         }
 959                 }
 960                 # If this is a revision of the media page for new version
 961                 # of a file do one common commit for both file and media page.
 962                 # Else do commit only for that page.
 963                 print STDERR "$n/", scalar(@$revision_ids), ": Revision #$rev->{revid} of $commit{title}\n";
 964                 import_file_revision(\%commit, ($fetch_from == 1), $n_actual, \%mediafile);
 965         }
 966
 967         return $n_actual;
 968 }
 969
 970 sub error_non_fast_forward {
 971         my $advice = run_git("config --bool advice.pushNonFastForward");
 972         chomp($advice);
 973         if ($advice ne "false") {
 974                 # Native git-push would show this after the summary.
 975                 # We can't ask it to display it cleanly, so print it
 976                 # ourselves before.
 977                 print STDERR "To prevent you from losing history, non-fast-forward updates were rejected\n";
 978                 print STDERR "Merge the remote changes (e.g. 'git pull') before pushing again. See the\n";
 979                 print STDERR "'Note about fast-forwards' section of 'git push --help' for details.\n";
 980         }
 981         print STDOUT "error $_[0] \"non-fast-forward\"\n";
 982         return 0;
 983 }
 984
 985 sub mw_upload_file {
 986         my $complete_file_name = shift;
 987         my $new_sha1 = shift;
 988         my $extension = shift;
 989         my $file_deleted = shift;
 990         my $summary = shift;
 991         my $newrevid;
 992         my $path = "File:" . $complete_file_name;
 993         my %hashFiles = get_allowed_file_extensions();
 994         if (!exists($hashFiles{$extension})) {
 995                 print STDERR "$complete_file_name is not a permitted file on this wiki.\n";
 996                 print STDERR "Check the configuration of file uploads in your mediawiki.\n";
 997                 return $newrevid;
 998         }
 999         # Deleting and uploading a file requires a priviledged user
1000         if ($file_deleted) {
1001                 mw_connect_maybe();
1002                 my $query = {
1003                         action => 'delete',
1004                         title => $path,
1005                         reason => $summary
1006                 };
1007                 if (!$mediawiki->edit($query)) {
1008                         print STDERR "Failed to delete file on remote wiki\n";
1009                         print STDERR "Check your permissions on the remote site. Error code:\n";
1010                         print STDERR $mediawiki->{error}->{code} . ':' . $mediawiki->{error}->{details};
1011                         exit 1;
1012                 }
1013         } else {
1014                 # Don't let perl try to interpret file content as UTF-8 => use "raw"
1015                 my $content = run_git("cat-file blob $new_sha1", "raw");
1016                 if ($content ne "") {
1017                         mw_connect_maybe();
1018                         $mediawiki->{config}->{upload_url} =
1019                                 "$url/index.php/Special:Upload";
1020                         $mediawiki->edit({
1021                                 action => 'upload',
1022                                 filename => $complete_file_name,
1023                                 comment => $summary,
1024                                 file => [undef,
1025                                          $complete_file_name,
1026                                          Content => $content],
1027                                 ignorewarnings => 1,
1028                         }, {
1029                                 skip_encoding => 1
1030                         } ) || die $mediawiki->{error}->{code} . ':'
1031                                  . $mediawiki->{error}->{details};
1032                         my $last_file_page = $mediawiki->get_page({title => $path});
1033                         $newrevid = $last_file_page->{revid};
1034                         print STDERR "Pushed file: $new_sha1 - $complete_file_name.\n";
1035                 } else {
1036                         print STDERR "Empty file $complete_file_name not pushed.\n";
1037                 }
1038         }
1039         return $newrevid;
1040 }
1041
1042 sub mw_push_file {
1043         my $diff_info = shift;
1044         # $diff_info contains a string in this format:
1045         # 100644 100644 <sha1_of_blob_before_commit> <sha1_of_blob_now> <status>
1046         my @diff_info_split = split(/[ \t]/, $diff_info);
1047
1048         # Filename, including .mw extension
1049         my $complete_file_name = shift;
1050         # Commit message
1051         my $summary = shift;
1052         # MediaWiki revision number. Keep the previous one by default,
1053         # in case there's no edit to perform.
1054         my $oldrevid = shift;
1055         my $newrevid;
1056
1057         if ($summary eq EMPTY_MESSAGE) {
1058                 $summary = '';
1059         }
1060
1061         my $new_sha1 = $diff_info_split[3];
1062         my $old_sha1 = $diff_info_split[2];
1063         my $page_created = ($old_sha1 eq NULL_SHA1);
1064         my $page_deleted = ($new_sha1 eq NULL_SHA1);
1065         $complete_file_name = mediawiki_clean_filename($complete_file_name);
1066
1067         my ($title, $extension) = $complete_file_name =~ /^(.*)\.([^\.]*)$/;
1068         if (!defined($extension)) {
1069                 $extension = "";
1070         }
1071         if ($extension eq "mw") {
1072                 my $ns = get_mw_namespace_id_for_page($complete_file_name);
1073                 if ($ns && $ns == get_mw_namespace_id("File") && (!$export_media)) {
1074                         print STDERR "Ignoring media file related page: $complete_file_name\n";
1075                         return ($oldrevid, "ok");
1076                 }
1077                 my $file_content;
1078                 if ($page_deleted) {
1079                         # Deleting a page usually requires
1080                         # special privileges. A common
1081                         # convention is to replace the page
1082                         # with this content instead:
1083                         $file_content = DELETED_CONTENT;
1084                 } else {
1085                         $file_content = run_git("cat-file blob $new_sha1");
1086                 }
1087
1088                 mw_connect_maybe();
1089
1090                 my $result = $mediawiki->edit( {
1091                         action => 'edit',
1092                         summary => $summary,
1093                         title => $title,
1094                         basetimestamp => $basetimestamps{$oldrevid},
1095                         text => mediawiki_clean($file_content, $page_created),
1096                                   }, {
1097                                           skip_encoding => 1 # Helps with names with accentuated characters
1098                                   });
1099                 if (!$result) {
1100                         if ($mediawiki->{error}->{code} == 3) {
1101                                 # edit conflicts, considered as non-fast-forward
1102                                 print STDERR 'Warning: Error ' .
1103                                     $mediawiki->{error}->{code} .
1104                                     ' from mediwiki: ' . $mediawiki->{error}->{details} .
1105                                     ".\n";
1106                                 return ($oldrevid, "non-fast-forward");
1107                         } else {
1108                                 # Other errors. Shouldn't happen => just die()
1109                                 die 'Fatal: Error ' .
1110                                     $mediawiki->{error}->{code} .
1111                                     ' from mediwiki: ' . $mediawiki->{error}->{details};
1112                         }
1113                 }
1114                 $newrevid = $result->{edit}->{newrevid};
1115                 print STDERR "Pushed file: $new_sha1 - $title\n";
1116         } elsif ($export_media) {
1117                 $newrevid = mw_upload_file($complete_file_name, $new_sha1,
1118                                            $extension, $page_deleted,
1119                                            $summary);
1120         } else {
1121                 print STDERR "Ignoring media file $title\n";
1122         }
1123         $newrevid = ($newrevid or $oldrevid);
1124         return ($newrevid, "ok");
1125 }
1126
1127 sub mw_push {
1128         # multiple push statements can follow each other
1129         my @refsspecs = (shift, get_more_refs("push"));
1130         my $pushed;
1131         for my $refspec (@refsspecs) {
1132                 my ($force, $local, $remote) = $refspec =~ /^(\+)?([^:]*):([^:]*)$/
1133                     or die("Invalid refspec for push. Expected <src>:<dst> or +<src>:<dst>");
1134                 if ($force) {
1135                         print STDERR "Warning: forced push not allowed on a MediaWiki.\n";
1136                 }
1137                 if ($local eq "") {
1138                         print STDERR "Cannot delete remote branch on a MediaWiki\n";
1139                         print STDOUT "error $remote cannot delete\n";
1140                         next;
1141                 }
1142                 if ($remote ne "refs/heads/master") {
1143                         print STDERR "Only push to the branch 'master' is supported on a MediaWiki\n";
1144                         print STDOUT "error $remote only master allowed\n";
1145                         next;
1146                 }
1147                 if (mw_push_revision($local, $remote)) {
1148                         $pushed = 1;
1149                 }
1150         }
1151
1152         # Notify Git that the push is done
1153         print STDOUT "\n";
1154
1155         if ($pushed && $dumb_push) {
1156                 print STDERR "Just pushed some revisions to MediaWiki.\n";
1157                 print STDERR "The pushed revisions now have to be re-imported, and your current branch\n";
1158                 print STDERR "needs to be updated with these re-imported commits. You can do this with\n";
1159                 print STDERR "\n";
1160                 print STDERR "  git pull --rebase\n";
1161                 print STDERR "\n";
1162         }
1163 }
1164
1165 sub mw_push_revision {
1166         my $local = shift;
1167         my $remote = shift; # actually, this has to be "refs/heads/master" at this point.
1168         my $last_local_revid = get_last_local_revision();
1169         print STDERR ".\n"; # Finish sentence started by get_last_local_revision()
1170         my $last_remote_revid = get_last_remote_revision();
1171         my $mw_revision = $last_remote_revid;
1172
1173         # Get sha1 of commit pointed by local HEAD
1174         my $HEAD_sha1 = run_git("rev-parse $local 2>/dev/null"); chomp($HEAD_sha1);
1175         # Get sha1 of commit pointed by remotes/$remotename/master
1176         my $remoteorigin_sha1 = run_git("rev-parse refs/remotes/$remotename/master 2>/dev/null");
1177         chomp($remoteorigin_sha1);
1178
1179         if ($last_local_revid > 0 &&
1180             $last_local_revid < $last_remote_revid) {
1181                 return error_non_fast_forward($remote);
1182         }
1183
1184         if ($HEAD_sha1 eq $remoteorigin_sha1) {
1185                 # nothing to push
1186                 return 0;
1187         }
1188
1189         # Get every commit in between HEAD and refs/remotes/origin/master,
1190         # including HEAD and refs/remotes/origin/master
1191         my @commit_pairs = ();
1192         if ($last_local_revid > 0) {
1193                 my $parsed_sha1 = $remoteorigin_sha1;
1194                 # Find a path from last MediaWiki commit to pushed commit
1195                 print STDERR "Computing path from local to remote ...\n";
1196                 my @local_ancestry = split(/\n/, run_git("rev-list --boundary --parents $local ^$parsed_sha1"));
1197                 my %local_ancestry;
1198                 foreach my $line (@local_ancestry) {
1199                         if (my ($child, $parents) = $line =~ m/^-?([a-f0-9]+) ([a-f0-9 ]+)/) {
1200                                 foreach my $parent (split(' ', $parents)) {
1201                                         $local_ancestry{$parent} = $child;
1202                                 }
1203                         } elsif (!$line =~ m/^([a-f0-9]+)/) {
1204                                 die "Unexpected output from git rev-list: $line";
1205                         }
1206                 }
1207                 while ($parsed_sha1 ne $HEAD_sha1) {
1208                         my $child = $local_ancestry{$parsed_sha1};
1209                         if (!$child) {
1210                                 printf STDERR "Cannot find a path in history from remote commit to last commit\n";
1211                                 return error_non_fast_forward($remote);
1212                         }
1213                         push(@commit_pairs, [$parsed_sha1, $child]);
1214                         $parsed_sha1 = $child;
1215                 }
1216         } else {
1217                 # No remote mediawiki revision. Export the whole
1218                 # history (linearized with --first-parent)
1219                 print STDERR "Warning: no common ancestor, pushing complete history\n";
1220                 my $history = run_git("rev-list --first-parent --children $local");
1221                 my @history = split('\n', $history);
1222                 @history = @history[1..$#history];
1223                 foreach my $line (reverse @history) {
1224                         my @commit_info_split = split(/ |\n/, $line);
1225                         push(@commit_pairs, \@commit_info_split);
1226                 }
1227         }
1228
1229         foreach my $commit_info_split (@commit_pairs) {
1230                 my $sha1_child = @{$commit_info_split}[0];
1231                 my $sha1_commit = @{$commit_info_split}[1];
1232                 my $diff_infos = run_git("diff-tree -r --raw -z $sha1_child $sha1_commit");
1233                 # TODO: we could detect rename, and encode them with a #redirect on the wiki.
1234                 # TODO: for now, it's just a delete+add
1235                 my @diff_info_list = split(/\0/, $diff_infos);
1236                 # Keep the subject line of the commit message as mediawiki comment for the revision
1237                 my $commit_msg = run_git("log --no-walk --format=\"%s\" $sha1_commit");
1238                 chomp($commit_msg);
1239                 # Push every blob
1240                 while (@diff_info_list) {
1241                         my $status;
1242                         # git diff-tree -z gives an output like
1243                         # <metadata>\0<filename1>\0
1244                         # <metadata>\0<filename2>\0
1245                         # and we've split on \0.
1246                         my $info = shift(@diff_info_list);
1247                         my $file = shift(@diff_info_list);
1248                         ($mw_revision, $status) = mw_push_file($info, $file, $commit_msg, $mw_revision);
1249                         if ($status eq "non-fast-forward") {
1250                                 # we may already have sent part of the
1251                                 # commit to MediaWiki, but it's too
1252                                 # late to cancel it. Stop the push in
1253                                 # the middle, but still give an
1254                                 # accurate error message.
1255                                 return error_non_fast_forward($remote);
1256                         }
1257                         if ($status ne "ok") {
1258                                 die("Unknown error from mw_push_file()");
1259                         }
1260                 }
1261                 unless ($dumb_push) {
1262                         run_git("notes --ref=$remotename/mediawiki add -f -m \"mediawiki_revision: $mw_revision\" $sha1_commit");
1263                         run_git("update-ref -m \"Git-MediaWiki push\" refs/mediawiki/$remotename/master $sha1_commit $sha1_child");
1264                 }
1265         }
1266
1267         print STDOUT "ok $remote\n";
1268         return 1;
1269 }
1270
1271 sub get_allowed_file_extensions {
1272         mw_connect_maybe();
1273
1274         my $query = {
1275                 action => 'query',
1276                 meta => 'siteinfo',
1277                 siprop => 'fileextensions'
1278                 };
1279         my $result = $mediawiki->api($query);
1280         my @file_extensions= map $_->{ext},@{$result->{query}->{fileextensions}};
1281         my %hashFile = map {$_ => 1}@file_extensions;
1282
1283         return %hashFile;
1284 }
1285
1286 # In memory cache for MediaWiki namespace ids.
1287 my %namespace_id;
1288
1289 # Namespaces whose id is cached in the configuration file
1290 # (to avoid duplicates)
1291 my %cached_mw_namespace_id;
1292
1293 # Return MediaWiki id for a canonical namespace name.
1294 # Ex.: "File", "Project".
1295 sub get_mw_namespace_id {
1296         mw_connect_maybe();
1297         my $name = shift;
1298
1299         if (!exists $namespace_id{$name}) {
1300                 # Look at configuration file, if the record for that namespace is
1301                 # already cached. Namespaces are stored in form:
1302                 # "Name_of_namespace:Id_namespace", ex.: "File:6".
1303                 my @temp = split(/[\n]/, run_git("config --get-all remote."
1304                                                 . $remotename .".namespaceCache"));
1305                 chomp(@temp);
1306                 foreach my $ns (@temp) {
1307                         my ($n, $id) = split(/:/, $ns);
1308                         if ($id eq 'notANameSpace') {
1309                                 $namespace_id{$n} = {is_namespace => 0};
1310                         } else {
1311                                 $namespace_id{$n} = {is_namespace => 1, id => $id};
1312                         }
1313                         $cached_mw_namespace_id{$n} = 1;
1314                 }
1315         }
1316
1317         if (!exists $namespace_id{$name}) {
1318                 print STDERR "Namespace $name not found in cache, querying the wiki ...\n";
1319                 # NS not found => get namespace id from MW and store it in
1320                 # configuration file.
1321                 my $query = {
1322                         action => 'query',
1323                         meta => 'siteinfo',
1324                         siprop => 'namespaces'
1325                 };
1326                 my $result = $mediawiki->api($query);
1327
1328                 while (my ($id, $ns) = each(%{$result->{query}->{namespaces}})) {
1329                         if (defined($ns->{id}) && defined($ns->{canonical})) {
1330                                 $namespace_id{$ns->{canonical}} = {is_namespace => 1, id => $ns->{id}};
1331                                 if ($ns->{'*'}) {
1332                                         # alias (e.g. french Fichier: as alias for canonical File:)
1333                                         $namespace_id{$ns->{'*'}} = {is_namespace => 1, id => $ns->{id}};
1334                                 }
1335                         }
1336                 }
1337         }
1338
1339         my $ns = $namespace_id{$name};
1340         my $id;
1341
1342         unless (defined $ns) {
1343                 print STDERR "No such namespace $name on MediaWiki.\n";
1344                 $ns = {is_namespace => 0};
1345                 $namespace_id{$name} = $ns;
1346         }
1347
1348         if ($ns->{is_namespace}) {
1349                 $id = $ns->{id};
1350         }
1351
1352         # Store "notANameSpace" as special value for inexisting namespaces
1353         my $store_id = ($id || 'notANameSpace');
1354
1355         # Store explicitely requested namespaces on disk
1356         if (!exists $cached_mw_namespace_id{$name}) {
1357                 run_git("config --add remote.". $remotename
1358                         .".namespaceCache \"". $name .":". $store_id ."\"");
1359                 $cached_mw_namespace_id{$name} = 1;
1360         }
1361         return $id;
1362 }
1363
1364 sub get_mw_namespace_id_for_page {
1365         if (my ($namespace) = $_[0] =~ /^([^:]*):/) {
1366                 return get_mw_namespace_id($namespace);
1367         } else {
1368                 return;
1369         }
1370 }