Andrew's git / gitweb.git / contrib/mw-to-git/git-remote-mediawiki.perl
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contrib / mw-to-git / git-remote-mediawiki.perlon commit Merge branch 'nd/traces' (8f0c843)
   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
  14use strict;
  15use MediaWiki::API;
  16use Git;
  17use DateTime::Format::ISO8601;
  18
  19# By default, use UTF-8 to communicate with Git and the user
  20binmode STDERR, ":utf8";
  21binmode STDOUT, ":utf8";
  22
  23use URI::Escape;
  24use IPC::Open2;
  25
  26use warnings;
  27
  28# Mediawiki filenames can contain forward slashes. This variable decides by which pattern they should be replaced
  29use constant SLASH_REPLACEMENT => "%2F";
  30
  31# It's not always possible to delete pages (may require some
  32# privileges). Deleted pages are replaced with this content.
  33use constant DELETED_CONTENT => "[[Category:Deleted]]\n";
  34
  35# It's not possible to create empty pages. New empty files in Git are
  36# sent with this content instead.
  37use constant EMPTY_CONTENT => "<!-- empty page -->\n";
  38
  39# used to reflect file creation or deletion in diff.
  40use constant NULL_SHA1 => "0000000000000000000000000000000000000000";
  41
  42# Used on Git's side to reflect empty edit messages on the wiki
  43use constant EMPTY_MESSAGE => '*Empty MediaWiki Message*';
  44
  45my $remotename = $ARGV[0];
  46my $url = $ARGV[1];
  47
  48# Accept both space-separated and multiple keys in config file.
  49# Spaces should be written as _ anyway because we'll use chomp.
  50my @tracked_pages = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".pages"));
  51chomp(@tracked_pages);
  52
  53# Just like @tracked_pages, but for MediaWiki categories.
  54my @tracked_categories = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".categories"));
  55chomp(@tracked_categories);
  56
  57# Import media files on pull
  58my $import_media = run_git("config --get --bool remote.". $remotename .".mediaimport");
  59chomp($import_media);
  60$import_media = ($import_media eq "true");
  61
  62# Export media files on push
  63my $export_media = run_git("config --get --bool remote.". $remotename .".mediaexport");
  64chomp($export_media);
  65$export_media = !($export_media eq "false");
  66
  67my $wiki_login = run_git("config --get remote.". $remotename .".mwLogin");
  68# Note: mwPassword is discourraged. Use the credential system instead.
  69my $wiki_passwd = run_git("config --get remote.". $remotename .".mwPassword");
  70my $wiki_domain = run_git("config --get remote.". $remotename .".mwDomain");
  71chomp($wiki_login);
  72chomp($wiki_passwd);
  73chomp($wiki_domain);
  74
  75# Import only last revisions (both for clone and fetch)
  76my $shallow_import = run_git("config --get --bool remote.". $remotename .".shallow");
  77chomp($shallow_import);
  78$shallow_import = ($shallow_import eq "true");
  79
  80# Fetch (clone and pull) by revisions instead of by pages. This behavior
  81# is more efficient when we have a wiki with lots of pages and we fetch
  82# the revisions quite often so that they concern only few pages.
  83# Possible values:
  84# - by_rev: perform one query per new revision on the remote wiki
  85# - by_page: query each tracked page for new revision
  86my $fetch_strategy = run_git("config --get remote.$remotename.fetchStrategy");
  87unless ($fetch_strategy) {
  88        $fetch_strategy = run_git("config --get mediawiki.fetchStrategy");
  89}
  90chomp($fetch_strategy);
  91unless ($fetch_strategy) {
  92        $fetch_strategy = "by_page";
  93}
  94
  95# Dumb push: don't update notes and mediawiki ref to reflect the last push.
  96#
  97# Configurable with mediawiki.dumbPush, or per-remote with
  98# remote.<remotename>.dumbPush.
  99#
 100# This means the user will have to re-import the just-pushed
 101# revisions. On the other hand, this means that the Git revisions
 102# corresponding to MediaWiki revisions are all imported from the wiki,
 103# regardless of whether they were initially created in Git or from the
 104# web interface, hence all users will get the same history (i.e. if
 105# the push from Git to MediaWiki loses some information, everybody
 106# will get the history with information lost). If the import is
 107# deterministic, this means everybody gets the same sha1 for each
 108# MediaWiki revision.
 109my $dumb_push = run_git("config --get --bool remote.$remotename.dumbPush");
 110unless ($dumb_push) {
 111        $dumb_push = run_git("config --get --bool mediawiki.dumbPush");
 112}
 113chomp($dumb_push);
 114$dumb_push = ($dumb_push eq "true");
 115
 116my $wiki_name = $url;
 117$wiki_name =~ s/[^\/]*:\/\///;
 118# If URL is like http://user:password@example.com/, we clearly don't
 119# want the password in $wiki_name. While we're there, also remove user
 120# and '@' sign, to avoid author like MWUser@HTTPUser@host.com
 121$wiki_name =~ s/^.*@//;
 122
 123# Commands parser
 124my $entry;
 125my @cmd;
 126while (<STDIN>) {
 127        chomp;
 128        @cmd = split(/ /);
 129        if (defined($cmd[0])) {
 130                # Line not blank
 131                if ($cmd[0] eq "capabilities") {
 132                        die("Too many arguments for capabilities") unless (!defined($cmd[1]));
 133                        mw_capabilities();
 134                } elsif ($cmd[0] eq "list") {
 135                        die("Too many arguments for list") unless (!defined($cmd[2]));
 136                        mw_list($cmd[1]);
 137                } elsif ($cmd[0] eq "import") {
 138                        die("Invalid arguments for import") unless ($cmd[1] ne "" && !defined($cmd[2]));
 139                        mw_import($cmd[1]);
 140                } elsif ($cmd[0] eq "option") {
 141                        die("Too many arguments for option") unless ($cmd[1] ne "" && $cmd[2] ne "" && !defined($cmd[3]));
 142                        mw_option($cmd[1],$cmd[2]);
 143                } elsif ($cmd[0] eq "push") {
 144                        mw_push($cmd[1]);
 145                } else {
 146                        print STDERR "Unknown command. Aborting...\n";
 147                        last;
 148                }
 149        } else {
 150                # blank line: we should terminate
 151                last;
 152        }
 153
 154        BEGIN { $| = 1 } # flush STDOUT, to make sure the previous
 155                         # command is fully processed.
 156}
 157
 158########################## Functions ##############################
 159
 160# MediaWiki API instance, created lazily.
 161my $mediawiki;
 162
 163sub mw_connect_maybe {
 164        if ($mediawiki) {
 165                return;
 166        }
 167        $mediawiki = MediaWiki::API->new;
 168        $mediawiki->{config}->{api_url} = "$url/api.php";
 169        if ($wiki_login) {
 170                my %credential = (
 171                        'url' => $url,
 172                        'username' => $wiki_login,
 173                        'password' => $wiki_passwd
 174                );
 175                Git::credential(\%credential);
 176                my $request = {lgname => $credential{username},
 177                               lgpassword => $credential{password},
 178                               lgdomain => $wiki_domain};
 179                if ($mediawiki->login($request)) {
 180                        Git::credential(\%credential, 'approve');
 181                        print STDERR "Logged in mediawiki user \"$credential{username}\".\n";
 182                } else {
 183                        print STDERR "Failed to log in mediawiki user \"$credential{username}\" on $url\n";
 184                        print STDERR "  (error " .
 185                                $mediawiki->{error}->{code} . ': ' .
 186                                $mediawiki->{error}->{details} . ")\n";
 187                        Git::credential(\%credential, 'reject');
 188                        exit 1;
 189                }
 190        }
 191}
 192
 193sub fatal_mw_error {
 194        my $action = shift;
 195        print STDERR "fatal: could not $action.\n";
 196        print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 197        if ($url =~ /^https/) {
 198                print STDERR "fatal: make sure '$url/api.php' is a valid page\n";
 199                print STDERR "fatal: and the SSL certificate is correct.\n";
 200        } else {
 201                print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 202        }
 203        print STDERR "fatal: (error " .
 204            $mediawiki->{error}->{code} . ': ' .
 205            $mediawiki->{error}->{details} . ")\n";
 206        exit 1;
 207}
 208
 209## Functions for listing pages on the remote wiki
 210sub get_mw_tracked_pages {
 211        my $pages = shift;
 212        get_mw_page_list(\@tracked_pages, $pages);
 213}
 214
 215sub get_mw_page_list {
 216        my $page_list = shift;
 217        my $pages = shift;
 218        my @some_pages = @$page_list;
 219        while (@some_pages) {
 220                my $last = 50;
 221                if ($#some_pages < $last) {
 222                        $last = $#some_pages;
 223                }
 224                my @slice = @some_pages[0..$last];
 225                get_mw_first_pages(\@slice, $pages);
 226                @some_pages = @some_pages[51..$#some_pages];
 227        }
 228}
 229
 230sub get_mw_tracked_categories {
 231        my $pages = shift;
 232        foreach my $category (@tracked_categories) {
 233                if (index($category, ':') < 0) {
 234                        # Mediawiki requires the Category
 235                        # prefix, but let's not force the user
 236                        # to specify it.
 237                        $category = "Category:" . $category;
 238                }
 239                my $mw_pages = $mediawiki->list( {
 240                        action => 'query',
 241                        list => 'categorymembers',
 242                        cmtitle => $category,
 243                        cmlimit => 'max' } )
 244                        || die $mediawiki->{error}->{code} . ': '
 245                                . $mediawiki->{error}->{details};
 246                foreach my $page (@{$mw_pages}) {
 247                        $pages->{$page->{title}} = $page;
 248                }
 249        }
 250}
 251
 252sub get_mw_all_pages {
 253        my $pages = shift;
 254        # No user-provided list, get the list of pages from the API.
 255        my $mw_pages = $mediawiki->list({
 256                action => 'query',
 257                list => 'allpages',
 258                aplimit => 'max'
 259        });
 260        if (!defined($mw_pages)) {
 261                fatal_mw_error("get the list of wiki pages");
 262        }
 263        foreach my $page (@{$mw_pages}) {
 264                $pages->{$page->{title}} = $page;
 265        }
 266}
 267
 268# queries the wiki for a set of pages. Meant to be used within a loop
 269# querying the wiki for slices of page list.
 270sub get_mw_first_pages {
 271        my $some_pages = shift;
 272        my @some_pages = @{$some_pages};
 273
 274        my $pages = shift;
 275
 276        # pattern 'page1|page2|...' required by the API
 277        my $titles = join('|', @some_pages);
 278
 279        my $mw_pages = $mediawiki->api({
 280                action => 'query',
 281                titles => $titles,
 282        });
 283        if (!defined($mw_pages)) {
 284                fatal_mw_error("query the list of wiki pages");
 285        }
 286        while (my ($id, $page) = each(%{$mw_pages->{query}->{pages}})) {
 287                if ($id < 0) {
 288                        print STDERR "Warning: page $page->{title} not found on wiki\n";
 289                } else {
 290                        $pages->{$page->{title}} = $page;
 291                }
 292        }
 293}
 294
 295# Get the list of pages to be fetched according to configuration.
 296sub get_mw_pages {
 297        mw_connect_maybe();
 298
 299        print STDERR "Listing pages on remote wiki...\n";
 300
 301        my %pages; # hash on page titles to avoid duplicates
 302        my $user_defined;
 303        if (@tracked_pages) {
 304                $user_defined = 1;
 305                # The user provided a list of pages titles, but we
 306                # still need to query the API to get the page IDs.
 307                get_mw_tracked_pages(\%pages);
 308        }
 309        if (@tracked_categories) {
 310                $user_defined = 1;
 311                get_mw_tracked_categories(\%pages);
 312        }
 313        if (!$user_defined) {
 314                get_mw_all_pages(\%pages);
 315        }
 316        if ($import_media) {
 317                print STDERR "Getting media files for selected pages...\n";
 318                if ($user_defined) {
 319                        get_linked_mediafiles(\%pages);
 320                } else {
 321                        get_all_mediafiles(\%pages);
 322                }
 323        }
 324        print STDERR (scalar keys %pages) . " pages found.\n";
 325        return %pages;
 326}
 327
 328# usage: $out = run_git("command args");
 329#        $out = run_git("command args", "raw"); # don't interpret output as UTF-8.
 330sub run_git {
 331        my $args = shift;
 332        my $encoding = (shift || "encoding(UTF-8)");
 333        open(my $git, "-|:$encoding", "git " . $args);
 334        my $res = do { local $/; <$git> };
 335        close($git);
 336
 337        return $res;
 338}
 339
 340
 341sub get_all_mediafiles {
 342        my $pages = shift;
 343        # Attach list of all pages for media files from the API,
 344        # they are in a different namespace, only one namespace
 345        # can be queried at the same moment
 346        my $mw_pages = $mediawiki->list({
 347                action => 'query',
 348                list => 'allpages',
 349                apnamespace => get_mw_namespace_id("File"),
 350                aplimit => 'max'
 351        });
 352        if (!defined($mw_pages)) {
 353                print STDERR "fatal: could not get the list of pages for media files.\n";
 354                print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 355                print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 356                exit 1;
 357        }
 358        foreach my $page (@{$mw_pages}) {
 359                $pages->{$page->{title}} = $page;
 360        }
 361}
 362
 363sub get_linked_mediafiles {
 364        my $pages = shift;
 365        my @titles = map $_->{title}, values(%{$pages});
 366
 367        # The query is split in small batches because of the MW API limit of
 368        # the number of links to be returned (500 links max).
 369        my $batch = 10;
 370        while (@titles) {
 371                if ($#titles < $batch) {
 372                        $batch = $#titles;
 373                }
 374                my @slice = @titles[0..$batch];
 375
 376                # pattern 'page1|page2|...' required by the API
 377                my $mw_titles = join('|', @slice);
 378
 379                # Media files could be included or linked from
 380                # a page, get all related
 381                my $query = {
 382                        action => 'query',
 383                        prop => 'links|images',
 384                        titles => $mw_titles,
 385                        plnamespace => get_mw_namespace_id("File"),
 386                        pllimit => 'max'
 387                };
 388                my $result = $mediawiki->api($query);
 389
 390                while (my ($id, $page) = each(%{$result->{query}->{pages}})) {
 391                        my @media_titles;
 392                        if (defined($page->{links})) {
 393                                my @link_titles = map $_->{title}, @{$page->{links}};
 394                                push(@media_titles, @link_titles);
 395                        }
 396                        if (defined($page->{images})) {
 397                                my @image_titles = map $_->{title}, @{$page->{images}};
 398                                push(@media_titles, @image_titles);
 399                        }
 400                        if (@media_titles) {
 401                                get_mw_page_list(\@media_titles, $pages);
 402                        }
 403                }
 404
 405                @titles = @titles[($batch+1)..$#titles];
 406        }
 407}
 408
 409sub get_mw_mediafile_for_page_revision {
 410        # Name of the file on Wiki, with the prefix.
 411        my $filename = shift;
 412        my $timestamp = shift;
 413        my %mediafile;
 414
 415        # Search if on a media file with given timestamp exists on
 416        # MediaWiki. In that case download the file.
 417        my $query = {
 418                action => 'query',
 419                prop => 'imageinfo',
 420                titles => "File:" . $filename,
 421                iistart => $timestamp,
 422                iiend => $timestamp,
 423                iiprop => 'timestamp|archivename|url',
 424                iilimit => 1
 425        };
 426        my $result = $mediawiki->api($query);
 427
 428        my ($fileid, $file) = each( %{$result->{query}->{pages}} );
 429        # If not defined it means there is no revision of the file for
 430        # given timestamp.
 431        if (defined($file->{imageinfo})) {
 432                $mediafile{title} = $filename;
 433
 434                my $fileinfo = pop(@{$file->{imageinfo}});
 435                $mediafile{timestamp} = $fileinfo->{timestamp};
 436                # Mediawiki::API's download function doesn't support https URLs
 437                # and can't download old versions of files.
 438                print STDERR "\tDownloading file $mediafile{title}, version $mediafile{timestamp}\n";
 439                $mediafile{content} = download_mw_mediafile($fileinfo->{url});
 440        }
 441        return %mediafile;
 442}
 443
 444sub download_mw_mediafile {
 445        my $url = shift;
 446
 447        my $response = $mediawiki->{ua}->get($url);
 448        if ($response->code == 200) {
 449                return $response->decoded_content;
 450        } else {
 451                print STDERR "Error downloading mediafile from :\n";
 452                print STDERR "URL: $url\n";
 453                print STDERR "Server response: " . $response->code . " " . $response->message . "\n";
 454                exit 1;
 455        }
 456}
 457
 458sub get_last_local_revision {
 459        # Get note regarding last mediawiki revision
 460        my $note = run_git("notes --ref=$remotename/mediawiki show refs/mediawiki/$remotename/master 2>/dev/null");
 461        my @note_info = split(/ /, $note);
 462
 463        my $lastrevision_number;
 464        if (!(defined($note_info[0]) && $note_info[0] eq "mediawiki_revision:")) {
 465                print STDERR "No previous mediawiki revision found";
 466                $lastrevision_number = 0;
 467        } else {
 468                # Notes are formatted : mediawiki_revision: #number
 469                $lastrevision_number = $note_info[1];
 470                chomp($lastrevision_number);
 471                print STDERR "Last local mediawiki revision found is $lastrevision_number";
 472        }
 473        return $lastrevision_number;
 474}
 475
 476# Remember the timestamp corresponding to a revision id.
 477my %basetimestamps;
 478
 479# Get the last remote revision without taking in account which pages are
 480# tracked or not. This function makes a single request to the wiki thus
 481# avoid a loop onto all tracked pages. This is useful for the fetch-by-rev
 482# option.
 483sub get_last_global_remote_rev {
 484        mw_connect_maybe();
 485
 486        my $query = {
 487                action => 'query',
 488                list => 'recentchanges',
 489                prop => 'revisions',
 490                rclimit => '1',
 491                rcdir => 'older',
 492        };
 493        my $result = $mediawiki->api($query);
 494        return $result->{query}->{recentchanges}[0]->{revid};
 495}
 496
 497# Get the last remote revision concerning the tracked pages and the tracked
 498# categories.
 499sub get_last_remote_revision {
 500        mw_connect_maybe();
 501
 502        my %pages_hash = get_mw_pages();
 503        my @pages = values(%pages_hash);
 504
 505        my $max_rev_num = 0;
 506
 507        print STDERR "Getting last revision id on tracked pages...\n";
 508
 509        foreach my $page (@pages) {
 510                my $id = $page->{pageid};
 511
 512                my $query = {
 513                        action => 'query',
 514                        prop => 'revisions',
 515                        rvprop => 'ids|timestamp',
 516                        pageids => $id,
 517                };
 518
 519                my $result = $mediawiki->api($query);
 520
 521                my $lastrev = pop(@{$result->{query}->{pages}->{$id}->{revisions}});
 522
 523                $basetimestamps{$lastrev->{revid}} = $lastrev->{timestamp};
 524
 525                $max_rev_num = ($lastrev->{revid} > $max_rev_num ? $lastrev->{revid} : $max_rev_num);
 526        }
 527
 528        print STDERR "Last remote revision found is $max_rev_num.\n";
 529        return $max_rev_num;
 530}
 531
 532# Clean content before sending it to MediaWiki
 533sub mediawiki_clean {
 534        my $string = shift;
 535        my $page_created = shift;
 536        # Mediawiki does not allow blank space at the end of a page and ends with a single \n.
 537        # This function right trims a string and adds a \n at the end to follow this rule
 538        $string =~ s/\s+$//;
 539        if ($string eq "" && $page_created) {
 540                # Creating empty pages is forbidden.
 541                $string = EMPTY_CONTENT;
 542        }
 543        return $string."\n";
 544}
 545
 546# Filter applied on MediaWiki data before adding them to Git
 547sub mediawiki_smudge {
 548        my $string = shift;
 549        if ($string eq EMPTY_CONTENT) {
 550                $string = "";
 551        }
 552        # This \n is important. This is due to mediawiki's way to handle end of files.
 553        return $string."\n";
 554}
 555
 556sub mediawiki_clean_filename {
 557        my $filename = shift;
 558        $filename =~ s/@{[SLASH_REPLACEMENT]}/\//g;
 559        # [, ], |, {, and } are forbidden by MediaWiki, even URL-encoded.
 560        # Do a variant of URL-encoding, i.e. looks like URL-encoding,
 561        # but with _ added to prevent MediaWiki from thinking this is
 562        # an actual special character.
 563        $filename =~ s/[\[\]\{\}\|]/sprintf("_%%_%x", ord($&))/ge;
 564        # If we use the uri escape before
 565        # we should unescape here, before anything
 566
 567        return $filename;
 568}
 569
 570sub mediawiki_smudge_filename {
 571        my $filename = shift;
 572        $filename =~ s/\//@{[SLASH_REPLACEMENT]}/g;
 573        $filename =~ s/ /_/g;
 574        # Decode forbidden characters encoded in mediawiki_clean_filename
 575        $filename =~ s/_%_([0-9a-fA-F][0-9a-fA-F])/sprintf("%c", hex($1))/ge;
 576        return $filename;
 577}
 578
 579sub literal_data {
 580        my ($content) = @_;
 581        print STDOUT "data ", bytes::length($content), "\n", $content;
 582}
 583
 584sub literal_data_raw {
 585        # Output possibly binary content.
 586        my ($content) = @_;
 587        # Avoid confusion between size in bytes and in characters
 588        utf8::downgrade($content);
 589        binmode STDOUT, ":raw";
 590        print STDOUT "data ", bytes::length($content), "\n", $content;
 591        binmode STDOUT, ":utf8";
 592}
 593
 594sub mw_capabilities {
 595        # Revisions are imported to the private namespace
 596        # refs/mediawiki/$remotename/ by the helper and fetched into
 597        # refs/remotes/$remotename later by fetch.
 598        print STDOUT "refspec refs/heads/*:refs/mediawiki/$remotename/*\n";
 599        print STDOUT "import\n";
 600        print STDOUT "list\n";
 601        print STDOUT "push\n";
 602        print STDOUT "\n";
 603}
 604
 605sub mw_list {
 606        # MediaWiki do not have branches, we consider one branch arbitrarily
 607        # called master, and HEAD pointing to it.
 608        print STDOUT "? refs/heads/master\n";
 609        print STDOUT "\@refs/heads/master HEAD\n";
 610        print STDOUT "\n";
 611}
 612
 613sub mw_option {
 614        print STDERR "remote-helper command 'option $_[0]' not yet implemented\n";
 615        print STDOUT "unsupported\n";
 616}
 617
 618sub fetch_mw_revisions_for_page {
 619        my $page = shift;
 620        my $id = shift;
 621        my $fetch_from = shift;
 622        my @page_revs = ();
 623        my $query = {
 624                action => 'query',
 625                prop => 'revisions',
 626                rvprop => 'ids',
 627                rvdir => 'newer',
 628                rvstartid => $fetch_from,
 629                rvlimit => 500,
 630                pageids => $id,
 631        };
 632
 633        my $revnum = 0;
 634        # Get 500 revisions at a time due to the mediawiki api limit
 635        while (1) {
 636                my $result = $mediawiki->api($query);
 637
 638                # Parse each of those 500 revisions
 639                foreach my $revision (@{$result->{query}->{pages}->{$id}->{revisions}}) {
 640                        my $page_rev_ids;
 641                        $page_rev_ids->{pageid} = $page->{pageid};
 642                        $page_rev_ids->{revid} = $revision->{revid};
 643                        push(@page_revs, $page_rev_ids);
 644                        $revnum++;
 645                }
 646                last unless $result->{'query-continue'};
 647                $query->{rvstartid} = $result->{'query-continue'}->{revisions}->{rvstartid};
 648        }
 649        if ($shallow_import && @page_revs) {
 650                print STDERR "  Found 1 revision (shallow import).\n";
 651                @page_revs = sort {$b->{revid} <=> $a->{revid}} (@page_revs);
 652                return $page_revs[0];
 653        }
 654        print STDERR "  Found ", $revnum, " revision(s).\n";
 655        return @page_revs;
 656}
 657
 658sub fetch_mw_revisions {
 659        my $pages = shift; my @pages = @{$pages};
 660        my $fetch_from = shift;
 661
 662        my @revisions = ();
 663        my $n = 1;
 664        foreach my $page (@pages) {
 665                my $id = $page->{pageid};
 666
 667                print STDERR "page $n/", scalar(@pages), ": ". $page->{title} ."\n";
 668                $n++;
 669                my @page_revs = fetch_mw_revisions_for_page($page, $id, $fetch_from);
 670                @revisions = (@page_revs, @revisions);
 671        }
 672
 673        return ($n, @revisions);
 674}
 675
 676sub fe_escape_path {
 677    my $path = shift;
 678    $path =~ s/\\/\\\\/g;
 679    $path =~ s/"/\\"/g;
 680    $path =~ s/\n/\\n/g;
 681    return '"' . $path . '"';
 682}
 683
 684sub import_file_revision {
 685        my $commit = shift;
 686        my %commit = %{$commit};
 687        my $full_import = shift;
 688        my $n = shift;
 689        my $mediafile = shift;
 690        my %mediafile;
 691        if ($mediafile) {
 692                %mediafile = %{$mediafile};
 693        }
 694
 695        my $title = $commit{title};
 696        my $comment = $commit{comment};
 697        my $content = $commit{content};
 698        my $author = $commit{author};
 699        my $date = $commit{date};
 700
 701        print STDOUT "commit refs/mediawiki/$remotename/master\n";
 702        print STDOUT "mark :$n\n";
 703        print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 704        literal_data($comment);
 705
 706        # If it's not a clone, we need to know where to start from
 707        if (!$full_import && $n == 1) {
 708                print STDOUT "from refs/mediawiki/$remotename/master^0\n";
 709        }
 710        if ($content ne DELETED_CONTENT) {
 711                print STDOUT "M 644 inline " .
 712                    fe_escape_path($title . ".mw") . "\n";
 713                literal_data($content);
 714                if (%mediafile) {
 715                        print STDOUT "M 644 inline "
 716                            . fe_escape_path($mediafile{title}) . "\n";
 717                        literal_data_raw($mediafile{content});
 718                }
 719                print STDOUT "\n\n";
 720        } else {
 721                print STDOUT "D " . fe_escape_path($title . ".mw") . "\n";
 722        }
 723
 724        # mediawiki revision number in the git note
 725        if ($full_import && $n == 1) {
 726                print STDOUT "reset refs/notes/$remotename/mediawiki\n";
 727        }
 728        print STDOUT "commit refs/notes/$remotename/mediawiki\n";
 729        print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 730        literal_data("Note added by git-mediawiki during import");
 731        if (!$full_import && $n == 1) {
 732                print STDOUT "from refs/notes/$remotename/mediawiki^0\n";
 733        }
 734        print STDOUT "N inline :$n\n";
 735        literal_data("mediawiki_revision: " . $commit{mw_revision});
 736        print STDOUT "\n\n";
 737}
 738
 739# parse a sequence of
 740# <cmd> <arg1>
 741# <cmd> <arg2>
 742# \n
 743# (like batch sequence of import and sequence of push statements)
 744sub get_more_refs {
 745        my $cmd = shift;
 746        my @refs;
 747        while (1) {
 748                my $line = <STDIN>;
 749                if ($line =~ m/^$cmd (.*)$/) {
 750                        push(@refs, $1);
 751                } elsif ($line eq "\n") {
 752                        return @refs;
 753                } else {
 754                        die("Invalid command in a '$cmd' batch: ". $_);
 755                }
 756        }
 757}
 758
 759sub mw_import {
 760        # multiple import commands can follow each other.
 761        my @refs = (shift, get_more_refs("import"));
 762        foreach my $ref (@refs) {
 763                mw_import_ref($ref);
 764        }
 765        print STDOUT "done\n";
 766}
 767
 768sub mw_import_ref {
 769        my $ref = shift;
 770        # The remote helper will call "import HEAD" and
 771        # "import refs/heads/master".
 772        # Since HEAD is a symbolic ref to master (by convention,
 773        # followed by the output of the command "list" that we gave),
 774        # we don't need to do anything in this case.
 775        if ($ref eq "HEAD") {
 776                return;
 777        }
 778
 779        mw_connect_maybe();
 780
 781        print STDERR "Searching revisions...\n";
 782        my $last_local = get_last_local_revision();
 783        my $fetch_from = $last_local + 1;
 784        if ($fetch_from == 1) {
 785                print STDERR ", fetching from beginning.\n";
 786        } else {
 787                print STDERR ", fetching from here.\n";
 788        }
 789
 790        my $n = 0;
 791        if ($fetch_strategy eq "by_rev") {
 792                print STDERR "Fetching & writing export data by revs...\n";
 793                $n = mw_import_ref_by_revs($fetch_from);
 794        } elsif ($fetch_strategy eq "by_page") {
 795                print STDERR "Fetching & writing export data by pages...\n";
 796                $n = mw_import_ref_by_pages($fetch_from);
 797        } else {
 798                print STDERR "fatal: invalid fetch strategy \"$fetch_strategy\".\n";
 799                print STDERR "Check your configuration variables remote.$remotename.fetchStrategy and mediawiki.fetchStrategy\n";
 800                exit 1;
 801        }
 802
 803        if ($fetch_from == 1 && $n == 0) {
 804                print STDERR "You appear to have cloned an empty MediaWiki.\n";
 805                # Something has to be done remote-helper side. If nothing is done, an error is
 806                # thrown saying that HEAD is referring to unknown object 0000000000000000000
 807                # and the clone fails.
 808        }
 809}
 810
 811sub mw_import_ref_by_pages {
 812
 813        my $fetch_from = shift;
 814        my %pages_hash = get_mw_pages();
 815        my @pages = values(%pages_hash);
 816
 817        my ($n, @revisions) = fetch_mw_revisions(\@pages, $fetch_from);
 818
 819        @revisions = sort {$a->{revid} <=> $b->{revid}} @revisions;
 820        my @revision_ids = map $_->{revid}, @revisions;
 821
 822        return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 823}
 824
 825sub mw_import_ref_by_revs {
 826
 827        my $fetch_from = shift;
 828        my %pages_hash = get_mw_pages();
 829
 830        my $last_remote = get_last_global_remote_rev();
 831        my @revision_ids = $fetch_from..$last_remote;
 832        return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 833}
 834
 835# Import revisions given in second argument (array of integers).
 836# Only pages appearing in the third argument (hash indexed by page titles)
 837# will be imported.
 838sub mw_import_revids {
 839        my $fetch_from = shift;
 840        my $revision_ids = shift;
 841        my $pages = shift;
 842
 843        my $n = 0;
 844        my $n_actual = 0;
 845        my $last_timestamp = 0; # Placeholer in case $rev->timestamp is undefined
 846
 847        foreach my $pagerevid (@$revision_ids) {
 848                # Count page even if we skip it, since we display
 849                # $n/$total and $total includes skipped pages.
 850                $n++;
 851
 852                # fetch the content of the pages
 853                my $query = {
 854                        action => 'query',
 855                        prop => 'revisions',
 856                        rvprop => 'content|timestamp|comment|user|ids',
 857                        revids => $pagerevid,
 858                };
 859
 860                my $result = $mediawiki->api($query);
 861
 862                if (!$result) {
 863                        die "Failed to retrieve modified page for revision $pagerevid";
 864                }
 865
 866                if (defined($result->{query}->{badrevids}->{$pagerevid})) {
 867                        # The revision id does not exist on the remote wiki.
 868                        next;
 869                }
 870
 871                if (!defined($result->{query}->{pages})) {
 872                        die "Invalid revision $pagerevid.";
 873                }
 874
 875                my @result_pages = values(%{$result->{query}->{pages}});
 876                my $result_page = $result_pages[0];
 877                my $rev = $result_pages[0]->{revisions}->[0];
 878
 879                my $page_title = $result_page->{title};
 880
 881                if (!exists($pages->{$page_title})) {
 882                        print STDERR "$n/", scalar(@$revision_ids),
 883                                ": Skipping revision #$rev->{revid} of $page_title\n";
 884                        next;
 885                }
 886
 887                $n_actual++;
 888
 889                my %commit;
 890                $commit{author} = $rev->{user} || 'Anonymous';
 891                $commit{comment} = $rev->{comment} || EMPTY_MESSAGE;
 892                $commit{title} = mediawiki_smudge_filename($page_title);
 893                $commit{mw_revision} = $rev->{revid};
 894                $commit{content} = mediawiki_smudge($rev->{'*'});
 895
 896                if (!defined($rev->{timestamp})) {
 897                        $last_timestamp++;
 898                } else {
 899                        $last_timestamp = $rev->{timestamp};
 900                }
 901                $commit{date} = DateTime::Format::ISO8601->parse_datetime($last_timestamp);
 902
 903                # Differentiates classic pages and media files.
 904                my ($namespace, $filename) = $page_title =~ /^([^:]*):(.*)$/;
 905                my %mediafile;
 906                if ($namespace) {
 907                        my $id = get_mw_namespace_id($namespace);
 908                        if ($id && $id == get_mw_namespace_id("File")) {
 909                                %mediafile = get_mw_mediafile_for_page_revision($filename, $rev->{timestamp});
 910                        }
 911                }
 912                # If this is a revision of the media page for new version
 913                # of a file do one common commit for both file and media page.
 914                # Else do commit only for that page.
 915                print STDERR "$n/", scalar(@$revision_ids), ": Revision #$rev->{revid} of $commit{title}\n";
 916                import_file_revision(\%commit, ($fetch_from == 1), $n_actual, \%mediafile);
 917        }
 918
 919        return $n_actual;
 920}
 921
 922sub error_non_fast_forward {
 923        my $advice = run_git("config --bool advice.pushNonFastForward");
 924        chomp($advice);
 925        if ($advice ne "false") {
 926                # Native git-push would show this after the summary.
 927                # We can't ask it to display it cleanly, so print it
 928                # ourselves before.
 929                print STDERR "To prevent you from losing history, non-fast-forward updates were rejected\n";
 930                print STDERR "Merge the remote changes (e.g. 'git pull') before pushing again. See the\n";
 931                print STDERR "'Note about fast-forwards' section of 'git push --help' for details.\n";
 932        }
 933        print STDOUT "error $_[0] \"non-fast-forward\"\n";
 934        return 0;
 935}
 936
 937sub mw_upload_file {
 938        my $complete_file_name = shift;
 939        my $new_sha1 = shift;
 940        my $extension = shift;
 941        my $file_deleted = shift;
 942        my $summary = shift;
 943        my $newrevid;
 944        my $path = "File:" . $complete_file_name;
 945        my %hashFiles = get_allowed_file_extensions();
 946        if (!exists($hashFiles{$extension})) {
 947                print STDERR "$complete_file_name is not a permitted file on this wiki.\n";
 948                print STDERR "Check the configuration of file uploads in your mediawiki.\n";
 949                return $newrevid;
 950        }
 951        # Deleting and uploading a file requires a priviledged user
 952        if ($file_deleted) {
 953                mw_connect_maybe();
 954                my $query = {
 955                        action => 'delete',
 956                        title => $path,
 957                        reason => $summary
 958                };
 959                if (!$mediawiki->edit($query)) {
 960                        print STDERR "Failed to delete file on remote wiki\n";
 961                        print STDERR "Check your permissions on the remote site. Error code:\n";
 962                        print STDERR $mediawiki->{error}->{code} . ':' . $mediawiki->{error}->{details};
 963                        exit 1;
 964                }
 965        } else {
 966                # Don't let perl try to interpret file content as UTF-8 => use "raw"
 967                my $content = run_git("cat-file blob $new_sha1", "raw");
 968                if ($content ne "") {
 969                        mw_connect_maybe();
 970                        $mediawiki->{config}->{upload_url} =
 971                                "$url/index.php/Special:Upload";
 972                        $mediawiki->edit({
 973                                action => 'upload',
 974                                filename => $complete_file_name,
 975                                comment => $summary,
 976                                file => [undef,
 977                                         $complete_file_name,
 978                                         Content => $content],
 979                                ignorewarnings => 1,
 980                        }, {
 981                                skip_encoding => 1
 982                        } ) || die $mediawiki->{error}->{code} . ':'
 983                                 . $mediawiki->{error}->{details};
 984                        my $last_file_page = $mediawiki->get_page({title => $path});
 985                        $newrevid = $last_file_page->{revid};
 986                        print STDERR "Pushed file: $new_sha1 - $complete_file_name.\n";
 987                } else {
 988                        print STDERR "Empty file $complete_file_name not pushed.\n";
 989                }
 990        }
 991        return $newrevid;
 992}
 993
 994sub mw_push_file {
 995        my $diff_info = shift;
 996        # $diff_info contains a string in this format:
 997        # 100644 100644 <sha1_of_blob_before_commit> <sha1_of_blob_now> <status>
 998        my @diff_info_split = split(/[ \t]/, $diff_info);
 999
1000        # Filename, including .mw extension
1001        my $complete_file_name = shift;
1002        # Commit message
1003        my $summary = shift;
1004        # MediaWiki revision number. Keep the previous one by default,
1005        # in case there's no edit to perform.
1006        my $oldrevid = shift;
1007        my $newrevid;
1008
1009        if ($summary eq EMPTY_MESSAGE) {
1010                $summary = '';
1011        }
1012
1013        my $new_sha1 = $diff_info_split[3];
1014        my $old_sha1 = $diff_info_split[2];
1015        my $page_created = ($old_sha1 eq NULL_SHA1);
1016        my $page_deleted = ($new_sha1 eq NULL_SHA1);
1017        $complete_file_name = mediawiki_clean_filename($complete_file_name);
1018
1019        my ($title, $extension) = $complete_file_name =~ /^(.*)\.([^\.]*)$/;
1020        if (!defined($extension)) {
1021                $extension = "";
1022        }
1023        if ($extension eq "mw") {
1024                my $ns = get_mw_namespace_id_for_page($complete_file_name);
1025                if ($ns && $ns == get_mw_namespace_id("File") && (!$export_media)) {
1026                        print STDERR "Ignoring media file related page: $complete_file_name\n";
1027                        return ($oldrevid, "ok");
1028                }
1029                my $file_content;
1030                if ($page_deleted) {
1031                        # Deleting a page usually requires
1032                        # special privileges. A common
1033                        # convention is to replace the page
1034                        # with this content instead:
1035                        $file_content = DELETED_CONTENT;
1036                } else {
1037                        $file_content = run_git("cat-file blob $new_sha1");
1038                }
1039
1040                mw_connect_maybe();
1041
1042                my $result = $mediawiki->edit( {
1043                        action => 'edit',
1044                        summary => $summary,
1045                        title => $title,
1046                        basetimestamp => $basetimestamps{$oldrevid},
1047                        text => mediawiki_clean($file_content, $page_created),
1048                                  }, {
1049                                          skip_encoding => 1 # Helps with names with accentuated characters
1050                                  });
1051                if (!$result) {
1052                        if ($mediawiki->{error}->{code} == 3) {
1053                                # edit conflicts, considered as non-fast-forward
1054                                print STDERR 'Warning: Error ' .
1055                                    $mediawiki->{error}->{code} .
1056                                    ' from mediwiki: ' . $mediawiki->{error}->{details} .
1057                                    ".\n";
1058                                return ($oldrevid, "non-fast-forward");
1059                        } else {
1060                                # Other errors. Shouldn't happen => just die()
1061                                die 'Fatal: Error ' .
1062                                    $mediawiki->{error}->{code} .
1063                                    ' from mediwiki: ' . $mediawiki->{error}->{details};
1064                        }
1065                }
1066                $newrevid = $result->{edit}->{newrevid};
1067                print STDERR "Pushed file: $new_sha1 - $title\n";
1068        } elsif ($export_media) {
1069                $newrevid = mw_upload_file($complete_file_name, $new_sha1,
1070                                           $extension, $page_deleted,
1071                                           $summary);
1072        } else {
1073                print STDERR "Ignoring media file $title\n";
1074        }
1075        $newrevid = ($newrevid or $oldrevid);
1076        return ($newrevid, "ok");
1077}
1078
1079sub mw_push {
1080        # multiple push statements can follow each other
1081        my @refsspecs = (shift, get_more_refs("push"));
1082        my $pushed;
1083        for my $refspec (@refsspecs) {
1084                my ($force, $local, $remote) = $refspec =~ /^(\+)?([^:]*):([^:]*)$/
1085                    or die("Invalid refspec for push. Expected <src>:<dst> or +<src>:<dst>");
1086                if ($force) {
1087                        print STDERR "Warning: forced push not allowed on a MediaWiki.\n";
1088                }
1089                if ($local eq "") {
1090                        print STDERR "Cannot delete remote branch on a MediaWiki\n";
1091                        print STDOUT "error $remote cannot delete\n";
1092                        next;
1093                }
1094                if ($remote ne "refs/heads/master") {
1095                        print STDERR "Only push to the branch 'master' is supported on a MediaWiki\n";
1096                        print STDOUT "error $remote only master allowed\n";
1097                        next;
1098                }
1099                if (mw_push_revision($local, $remote)) {
1100                        $pushed = 1;
1101                }
1102        }
1103
1104        # Notify Git that the push is done
1105        print STDOUT "\n";
1106
1107        if ($pushed && $dumb_push) {
1108                print STDERR "Just pushed some revisions to MediaWiki.\n";
1109                print STDERR "The pushed revisions now have to be re-imported, and your current branch\n";
1110                print STDERR "needs to be updated with these re-imported commits. You can do this with\n";
1111                print STDERR "\n";
1112                print STDERR "  git pull --rebase\n";
1113                print STDERR "\n";
1114        }
1115}
1116
1117sub mw_push_revision {
1118        my $local = shift;
1119        my $remote = shift; # actually, this has to be "refs/heads/master" at this point.
1120        my $last_local_revid = get_last_local_revision();
1121        print STDERR ".\n"; # Finish sentence started by get_last_local_revision()
1122        my $last_remote_revid = get_last_remote_revision();
1123        my $mw_revision = $last_remote_revid;
1124
1125        # Get sha1 of commit pointed by local HEAD
1126        my $HEAD_sha1 = run_git("rev-parse $local 2>/dev/null"); chomp($HEAD_sha1);
1127        # Get sha1 of commit pointed by remotes/$remotename/master
1128        my $remoteorigin_sha1 = run_git("rev-parse refs/remotes/$remotename/master 2>/dev/null");
1129        chomp($remoteorigin_sha1);
1130
1131        if ($last_local_revid > 0 &&
1132            $last_local_revid < $last_remote_revid) {
1133                return error_non_fast_forward($remote);
1134        }
1135
1136        if ($HEAD_sha1 eq $remoteorigin_sha1) {
1137                # nothing to push
1138                return 0;
1139        }
1140
1141        # Get every commit in between HEAD and refs/remotes/origin/master,
1142        # including HEAD and refs/remotes/origin/master
1143        my @commit_pairs = ();
1144        if ($last_local_revid > 0) {
1145                my $parsed_sha1 = $remoteorigin_sha1;
1146                # Find a path from last MediaWiki commit to pushed commit
1147                print STDERR "Computing path from local to remote ...\n";
1148                my @local_ancestry = split(/\n/, run_git("rev-list --boundary --parents $local ^$parsed_sha1"));
1149                my %local_ancestry;
1150                foreach my $line (@local_ancestry) {
1151                        if (my ($child, $parents) = $line =~ m/^-?([a-f0-9]+) ([a-f0-9 ]+)/) {
1152                                foreach my $parent (split(' ', $parents)) {
1153                                        $local_ancestry{$parent} = $child;
1154                                }
1155                        } elsif (!$line =~ m/^([a-f0-9]+)/) {
1156                                die "Unexpected output from git rev-list: $line";
1157                        }
1158                }
1159                while ($parsed_sha1 ne $HEAD_sha1) {
1160                        my $child = $local_ancestry{$parsed_sha1};
1161                        if (!$child) {
1162                                printf STDERR "Cannot find a path in history from remote commit to last commit\n";
1163                                return error_non_fast_forward($remote);
1164                        }
1165                        push(@commit_pairs, [$parsed_sha1, $child]);
1166                        $parsed_sha1 = $child;
1167                }
1168        } else {
1169                # No remote mediawiki revision. Export the whole
1170                # history (linearized with --first-parent)
1171                print STDERR "Warning: no common ancestor, pushing complete history\n";
1172                my $history = run_git("rev-list --first-parent --children $local");
1173                my @history = split('\n', $history);
1174                @history = @history[1..$#history];
1175                foreach my $line (reverse @history) {
1176                        my @commit_info_split = split(/ |\n/, $line);
1177                        push(@commit_pairs, \@commit_info_split);
1178                }
1179        }
1180
1181        foreach my $commit_info_split (@commit_pairs) {
1182                my $sha1_child = @{$commit_info_split}[0];
1183                my $sha1_commit = @{$commit_info_split}[1];
1184                my $diff_infos = run_git("diff-tree -r --raw -z $sha1_child $sha1_commit");
1185                # TODO: we could detect rename, and encode them with a #redirect on the wiki.
1186                # TODO: for now, it's just a delete+add
1187                my @diff_info_list = split(/\0/, $diff_infos);
1188                # Keep the subject line of the commit message as mediawiki comment for the revision
1189                my $commit_msg = run_git("log --no-walk --format=\"%s\" $sha1_commit");
1190                chomp($commit_msg);
1191                # Push every blob
1192                while (@diff_info_list) {
1193                        my $status;
1194                        # git diff-tree -z gives an output like
1195                        # <metadata>\0<filename1>\0
1196                        # <metadata>\0<filename2>\0
1197                        # and we've split on \0.
1198                        my $info = shift(@diff_info_list);
1199                        my $file = shift(@diff_info_list);
1200                        ($mw_revision, $status) = mw_push_file($info, $file, $commit_msg, $mw_revision);
1201                        if ($status eq "non-fast-forward") {
1202                                # we may already have sent part of the
1203                                # commit to MediaWiki, but it's too
1204                                # late to cancel it. Stop the push in
1205                                # the middle, but still give an
1206                                # accurate error message.
1207                                return error_non_fast_forward($remote);
1208                        }
1209                        if ($status ne "ok") {
1210                                die("Unknown error from mw_push_file()");
1211                        }
1212                }
1213                unless ($dumb_push) {
1214                        run_git("notes --ref=$remotename/mediawiki add -f -m \"mediawiki_revision: $mw_revision\" $sha1_commit");
1215                        run_git("update-ref -m \"Git-MediaWiki push\" refs/mediawiki/$remotename/master $sha1_commit $sha1_child");
1216                }
1217        }
1218
1219        print STDOUT "ok $remote\n";
1220        return 1;
1221}
1222
1223sub get_allowed_file_extensions {
1224        mw_connect_maybe();
1225
1226        my $query = {
1227                action => 'query',
1228                meta => 'siteinfo',
1229                siprop => 'fileextensions'
1230                };
1231        my $result = $mediawiki->api($query);
1232        my @file_extensions= map $_->{ext},@{$result->{query}->{fileextensions}};
1233        my %hashFile = map {$_ => 1}@file_extensions;
1234
1235        return %hashFile;
1236}
1237
1238# In memory cache for MediaWiki namespace ids.
1239my %namespace_id;
1240
1241# Namespaces whose id is cached in the configuration file
1242# (to avoid duplicates)
1243my %cached_mw_namespace_id;
1244
1245# Return MediaWiki id for a canonical namespace name.
1246# Ex.: "File", "Project".
1247sub get_mw_namespace_id {
1248        mw_connect_maybe();
1249        my $name = shift;
1250
1251        if (!exists $namespace_id{$name}) {
1252                # Look at configuration file, if the record for that namespace is
1253                # already cached. Namespaces are stored in form:
1254                # "Name_of_namespace:Id_namespace", ex.: "File:6".
1255                my @temp = split(/[\n]/, run_git("config --get-all remote."
1256                                                . $remotename .".namespaceCache"));
1257                chomp(@temp);
1258                foreach my $ns (@temp) {
1259                        my ($n, $id) = split(/:/, $ns);
1260                        if ($id eq 'notANameSpace') {
1261                                $namespace_id{$n} = {is_namespace => 0};
1262                        } else {
1263                                $namespace_id{$n} = {is_namespace => 1, id => $id};
1264                        }
1265                        $cached_mw_namespace_id{$n} = 1;
1266                }
1267        }
1268
1269        if (!exists $namespace_id{$name}) {
1270                print STDERR "Namespace $name not found in cache, querying the wiki ...\n";
1271                # NS not found => get namespace id from MW and store it in
1272                # configuration file.
1273                my $query = {
1274                        action => 'query',
1275                        meta => 'siteinfo',
1276                        siprop => 'namespaces'
1277                };
1278                my $result = $mediawiki->api($query);
1279
1280                while (my ($id, $ns) = each(%{$result->{query}->{namespaces}})) {
1281                        if (defined($ns->{id}) && defined($ns->{canonical})) {
1282                                $namespace_id{$ns->{canonical}} = {is_namespace => 1, id => $ns->{id}};
1283                                if ($ns->{'*'}) {
1284                                        # alias (e.g. french Fichier: as alias for canonical File:)
1285                                        $namespace_id{$ns->{'*'}} = {is_namespace => 1, id => $ns->{id}};
1286                                }
1287                        }
1288                }
1289        }
1290
1291        my $ns = $namespace_id{$name};
1292        my $id;
1293
1294        unless (defined $ns) {
1295                print STDERR "No such namespace $name on MediaWiki.\n";
1296                $ns = {is_namespace => 0};
1297                $namespace_id{$name} = $ns;
1298        }
1299
1300        if ($ns->{is_namespace}) {
1301                $id = $ns->{id};
1302        }
1303
1304        # Store "notANameSpace" as special value for inexisting namespaces
1305        my $store_id = ($id || 'notANameSpace');
1306
1307        # Store explicitely requested namespaces on disk
1308        if (!exists $cached_mw_namespace_id{$name}) {
1309                run_git("config --add remote.". $remotename
1310                        .".namespaceCache \"". $name .":". $store_id ."\"");
1311                $cached_mw_namespace_id{$name} = 1;
1312        }
1313        return $id;
1314}
1315
1316sub get_mw_namespace_id_for_page {
1317        if (my ($namespace) = $_[0] =~ /^([^:]*):/) {
1318                return get_mw_namespace_id($namespace);
1319        } else {
1320                return;
1321        }
1322}