Andrew's git - gitweb.git/blob

bc31ba49fcb862d1f11d5284f332d4eef17cb289
   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;
  18use warnings;
  19
  20# By default, use UTF-8 to communicate with Git and the user
  21binmode STDERR, ":encoding(UTF-8)";
  22binmode STDOUT, ":encoding(UTF-8)";
  23
  24use URI::Escape;
  25
  26# Mediawiki filenames can contain forward slashes. This variable decides by which pattern they should be replaced
  27use constant SLASH_REPLACEMENT => "%2F";
  28
  29# It's not always possible to delete pages (may require some
  30# privileges). Deleted pages are replaced with this content.
  31use constant DELETED_CONTENT => "[[Category:Deleted]]\n";
  32
  33# It's not possible to create empty pages. New empty files in Git are
  34# sent with this content instead.
  35use constant EMPTY_CONTENT => "<!-- empty page -->\n";
  36
  37# used to reflect file creation or deletion in diff.
  38use constant NULL_SHA1 => "0000000000000000000000000000000000000000";
  39
  40# Used on Git's side to reflect empty edit messages on the wiki
  41use constant EMPTY_MESSAGE => '*Empty MediaWiki Message*';
  42
  43my $remotename = $ARGV[0];
  44my $url = $ARGV[1];
  45
  46# Accept both space-separated and multiple keys in config file.
  47# Spaces should be written as _ anyway because we'll use chomp.
  48my @tracked_pages = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".pages"));
  49chomp(@tracked_pages);
  50
  51# Just like @tracked_pages, but for MediaWiki categories.
  52my @tracked_categories = split(/[ \n]/, run_git("config --get-all remote.". $remotename .".categories"));
  53chomp(@tracked_categories);
  54
  55# Import media files on pull
  56my $import_media = run_git("config --get --bool remote.". $remotename .".mediaimport");
  57chomp($import_media);
  58$import_media = ($import_media eq "true");
  59
  60# Export media files on push
  61my $export_media = run_git("config --get --bool remote.". $remotename .".mediaexport");
  62chomp($export_media);
  63$export_media = !($export_media eq "false");
  64
  65my $wiki_login = run_git("config --get remote.". $remotename .".mwLogin");
  66# Note: mwPassword is discourraged. Use the credential system instead.
  67my $wiki_passwd = run_git("config --get remote.". $remotename .".mwPassword");
  68my $wiki_domain = run_git("config --get remote.". $remotename .".mwDomain");
  69chomp($wiki_login);
  70chomp($wiki_passwd);
  71chomp($wiki_domain);
  72
  73# Import only last revisions (both for clone and fetch)
  74my $shallow_import = run_git("config --get --bool remote.". $remotename .".shallow");
  75chomp($shallow_import);
  76$shallow_import = ($shallow_import eq "true");
  77
  78# Fetch (clone and pull) by revisions instead of by pages. This behavior
  79# is more efficient when we have a wiki with lots of pages and we fetch
  80# the revisions quite often so that they concern only few pages.
  81# Possible values:
  82# - by_rev: perform one query per new revision on the remote wiki
  83# - by_page: query each tracked page for new revision
  84my $fetch_strategy = run_git("config --get remote.$remotename.fetchStrategy");
  85unless ($fetch_strategy) {
  86        $fetch_strategy = run_git("config --get mediawiki.fetchStrategy");
  87}
  88chomp($fetch_strategy);
  89unless ($fetch_strategy) {
  90        $fetch_strategy = "by_page";
  91}
  92
  93# Remember the timestamp corresponding to a revision id.
  94my %basetimestamps;
  95
  96# Dumb push: don't update notes and mediawiki ref to reflect the last push.
  97#
  98# Configurable with mediawiki.dumbPush, or per-remote with
  99# remote.<remotename>.dumbPush.
 100#
 101# This means the user will have to re-import the just-pushed
 102# revisions. On the other hand, this means that the Git revisions
 103# corresponding to MediaWiki revisions are all imported from the wiki,
 104# regardless of whether they were initially created in Git or from the
 105# web interface, hence all users will get the same history (i.e. if
 106# the push from Git to MediaWiki loses some information, everybody
 107# will get the history with information lost). If the import is
 108# deterministic, this means everybody gets the same sha1 for each
 109# MediaWiki revision.
 110my $dumb_push = run_git("config --get --bool remote.$remotename.dumbPush");
 111unless ($dumb_push) {
 112        $dumb_push = run_git("config --get --bool mediawiki.dumbPush");
 113}
 114chomp($dumb_push);
 115$dumb_push = ($dumb_push eq "true");
 116
 117my $wiki_name = $url;
 118$wiki_name =~ s{[^/]*://}{};
 119# If URL is like http://user:password@example.com/, we clearly don't
 120# want the password in $wiki_name. While we're there, also remove user
 121# and '@' sign, to avoid author like MWUser@HTTPUser@host.com
 122$wiki_name =~ s/^.*@//;
 123
 124# Commands parser
 125while (<STDIN>) {
 126        chomp;
 127
 128        if (!parse_command($_)) {
 129                last;
 130        }
 131
 132        BEGIN { $| = 1 } # flush STDOUT, to make sure the previous
 133                         # command is fully processed.
 134}
 135
 136########################## Functions ##############################
 137
 138sub parse_command {
 139        my ($line) = @_;
 140        my @cmd = split(/ /, $line);
 141        if (!defined $cmd[0]) {
 142                return 0;
 143        }
 144        if ($cmd[0] eq "capabilities") {
 145                die("Too many arguments for capabilities\n")
 146                    if (defined($cmd[1]));
 147                mw_capabilities();
 148        } elsif ($cmd[0] eq "list") {
 149                die("Too many arguments for list\n") if (defined($cmd[2]));
 150                mw_list($cmd[1]);
 151        } elsif ($cmd[0] eq "import") {
 152                die("Invalid arguments for import\n")
 153                    if ($cmd[1] eq "" || defined($cmd[2]));
 154                mw_import($cmd[1]);
 155        } elsif ($cmd[0] eq "option") {
 156                die("Too many arguments for option\n")
 157                    if ($cmd[1] eq "" || $cmd[2] eq "" || defined($cmd[3]));
 158                mw_option($cmd[1],$cmd[2]);
 159        } elsif ($cmd[0] eq "push") {
 160                mw_push($cmd[1]);
 161        } else {
 162                print STDERR "Unknown command. Aborting...\n";
 163                return 0;
 164        }
 165        return 1;
 166}
 167
 168# MediaWiki API instance, created lazily.
 169my $mediawiki;
 170
 171sub mw_connect_maybe {
 172        if ($mediawiki) {
 173                return;
 174        }
 175        $mediawiki = MediaWiki::API->new;
 176        $mediawiki->{config}->{api_url} = "$url/api.php";
 177        if ($wiki_login) {
 178                my %credential = (
 179                        'url' => $url,
 180                        'username' => $wiki_login,
 181                        'password' => $wiki_passwd
 182                );
 183                Git::credential(\%credential);
 184                my $request = {lgname => $credential{username},
 185                               lgpassword => $credential{password},
 186                               lgdomain => $wiki_domain};
 187                if ($mediawiki->login($request)) {
 188                        Git::credential(\%credential, 'approve');
 189                        print STDERR "Logged in mediawiki user \"$credential{username}\".\n";
 190                } else {
 191                        print STDERR "Failed to log in mediawiki user \"$credential{username}\" on $url\n";
 192                        print STDERR "  (error " .
 193                                $mediawiki->{error}->{code} . ': ' .
 194                                $mediawiki->{error}->{details} . ")\n";
 195                        Git::credential(\%credential, 'reject');
 196                        exit 1;
 197                }
 198        }
 199        return;
 200}
 201
 202sub fatal_mw_error {
 203        my $action = shift;
 204        print STDERR "fatal: could not $action.\n";
 205        print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 206        if ($url =~ /^https/) {
 207                print STDERR "fatal: make sure '$url/api.php' is a valid page\n";
 208                print STDERR "fatal: and the SSL certificate is correct.\n";
 209        } else {
 210                print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 211        }
 212        print STDERR "fatal: (error " .
 213            $mediawiki->{error}->{code} . ': ' .
 214            $mediawiki->{error}->{details} . ")\n";
 215        exit 1;
 216}
 217
 218## Functions for listing pages on the remote wiki
 219sub get_mw_tracked_pages {
 220        my $pages = shift;
 221        get_mw_page_list(\@tracked_pages, $pages);
 222        return;
 223}
 224
 225sub get_mw_page_list {
 226        my $page_list = shift;
 227        my $pages = shift;
 228        my @some_pages = @$page_list;
 229        while (@some_pages) {
 230                my $last_page = 50;
 231                if ($#some_pages < $last_page) {
 232                        $last_page = $#some_pages;
 233                }
 234                my @slice = @some_pages[0..$last_page];
 235                get_mw_first_pages(\@slice, $pages);
 236                @some_pages = @some_pages[51..$#some_pages];
 237        }
 238        return;
 239}
 240
 241sub get_mw_tracked_categories {
 242        my $pages = shift;
 243        foreach my $category (@tracked_categories) {
 244                if (index($category, ':') < 0) {
 245                        # Mediawiki requires the Category
 246                        # prefix, but let's not force the user
 247                        # to specify it.
 248                        $category = "Category:" . $category;
 249                }
 250                my $mw_pages = $mediawiki->list( {
 251                        action => 'query',
 252                        list => 'categorymembers',
 253                        cmtitle => $category,
 254                        cmlimit => 'max' } )
 255                        || die $mediawiki->{error}->{code} . ': '
 256                                . $mediawiki->{error}->{details} . "\n";
 257                foreach my $page (@{$mw_pages}) {
 258                        $pages->{$page->{title}} = $page;
 259                }
 260        }
 261        return;
 262}
 263
 264sub get_mw_all_pages {
 265        my $pages = shift;
 266        # No user-provided list, get the list of pages from the API.
 267        my $mw_pages = $mediawiki->list({
 268                action => 'query',
 269                list => 'allpages',
 270                aplimit => 'max'
 271        });
 272        if (!defined($mw_pages)) {
 273                fatal_mw_error("get the list of wiki pages");
 274        }
 275        foreach my $page (@{$mw_pages}) {
 276                $pages->{$page->{title}} = $page;
 277        }
 278        return;
 279}
 280
 281# queries the wiki for a set of pages. Meant to be used within a loop
 282# querying the wiki for slices of page list.
 283sub get_mw_first_pages {
 284        my $some_pages = shift;
 285        my @some_pages = @{$some_pages};
 286
 287        my $pages = shift;
 288
 289        # pattern 'page1|page2|...' required by the API
 290        my $titles = join('|', @some_pages);
 291
 292        my $mw_pages = $mediawiki->api({
 293                action => 'query',
 294                titles => $titles,
 295        });
 296        if (!defined($mw_pages)) {
 297                fatal_mw_error("query the list of wiki pages");
 298        }
 299        while (my ($id, $page) = each(%{$mw_pages->{query}->{pages}})) {
 300                if ($id < 0) {
 301                        print STDERR "Warning: page $page->{title} not found on wiki\n";
 302                } else {
 303                        $pages->{$page->{title}} = $page;
 304                }
 305        }
 306        return;
 307}
 308
 309# Get the list of pages to be fetched according to configuration.
 310sub get_mw_pages {
 311        mw_connect_maybe();
 312
 313        print STDERR "Listing pages on remote wiki...\n";
 314
 315        my %pages; # hash on page titles to avoid duplicates
 316        my $user_defined;
 317        if (@tracked_pages) {
 318                $user_defined = 1;
 319                # The user provided a list of pages titles, but we
 320                # still need to query the API to get the page IDs.
 321                get_mw_tracked_pages(\%pages);
 322        }
 323        if (@tracked_categories) {
 324                $user_defined = 1;
 325                get_mw_tracked_categories(\%pages);
 326        }
 327        if (!$user_defined) {
 328                get_mw_all_pages(\%pages);
 329        }
 330        if ($import_media) {
 331                print STDERR "Getting media files for selected pages...\n";
 332                if ($user_defined) {
 333                        get_linked_mediafiles(\%pages);
 334                } else {
 335                        get_all_mediafiles(\%pages);
 336                }
 337        }
 338        print STDERR (scalar keys %pages) . " pages found.\n";
 339        return %pages;
 340}
 341
 342# usage: $out = run_git("command args");
 343#        $out = run_git("command args", "raw"); # don't interpret output as UTF-8.
 344sub run_git {
 345        my $args = shift;
 346        my $encoding = (shift || "encoding(UTF-8)");
 347        open(my $git, "-|:$encoding", "git " . $args)
 348            or die "Unable to open: $!\n";
 349        my $res = do {
 350                local $/ = undef;
 351                <$git>
 352        };
 353        close($git);
 354
 355        return $res;
 356}
 357
 358
 359sub get_all_mediafiles {
 360        my $pages = shift;
 361        # Attach list of all pages for media files from the API,
 362        # they are in a different namespace, only one namespace
 363        # can be queried at the same moment
 364        my $mw_pages = $mediawiki->list({
 365                action => 'query',
 366                list => 'allpages',
 367                apnamespace => get_mw_namespace_id("File"),
 368                aplimit => 'max'
 369        });
 370        if (!defined($mw_pages)) {
 371                print STDERR "fatal: could not get the list of pages for media files.\n";
 372                print STDERR "fatal: '$url' does not appear to be a mediawiki\n";
 373                print STDERR "fatal: make sure '$url/api.php' is a valid page.\n";
 374                exit 1;
 375        }
 376        foreach my $page (@{$mw_pages}) {
 377                $pages->{$page->{title}} = $page;
 378        }
 379        return;
 380}
 381
 382sub get_linked_mediafiles {
 383        my $pages = shift;
 384        my @titles = map { $_->{title} } values(%{$pages});
 385
 386        # The query is split in small batches because of the MW API limit of
 387        # the number of links to be returned (500 links max).
 388        my $batch = 10;
 389        while (@titles) {
 390                if ($#titles < $batch) {
 391                        $batch = $#titles;
 392                }
 393                my @slice = @titles[0..$batch];
 394
 395                # pattern 'page1|page2|...' required by the API
 396                my $mw_titles = join('|', @slice);
 397
 398                # Media files could be included or linked from
 399                # a page, get all related
 400                my $query = {
 401                        action => 'query',
 402                        prop => 'links|images',
 403                        titles => $mw_titles,
 404                        plnamespace => get_mw_namespace_id("File"),
 405                        pllimit => 'max'
 406                };
 407                my $result = $mediawiki->api($query);
 408
 409                while (my ($id, $page) = each(%{$result->{query}->{pages}})) {
 410                        my @media_titles;
 411                        if (defined($page->{links})) {
 412                                my @link_titles
 413                                    = map { $_->{title} } @{$page->{links}};
 414                                push(@media_titles, @link_titles);
 415                        }
 416                        if (defined($page->{images})) {
 417                                my @image_titles
 418                                    = map { $_->{title} } @{$page->{images}};
 419                                push(@media_titles, @image_titles);
 420                        }
 421                        if (@media_titles) {
 422                                get_mw_page_list(\@media_titles, $pages);
 423                        }
 424                }
 425
 426                @titles = @titles[($batch+1)..$#titles];
 427        }
 428        return;
 429}
 430
 431sub get_mw_mediafile_for_page_revision {
 432        # Name of the file on Wiki, with the prefix.
 433        my $filename = shift;
 434        my $timestamp = shift;
 435        my %mediafile;
 436
 437        # Search if on a media file with given timestamp exists on
 438        # MediaWiki. In that case download the file.
 439        my $query = {
 440                action => 'query',
 441                prop => 'imageinfo',
 442                titles => "File:" . $filename,
 443                iistart => $timestamp,
 444                iiend => $timestamp,
 445                iiprop => 'timestamp|archivename|url',
 446                iilimit => 1
 447        };
 448        my $result = $mediawiki->api($query);
 449
 450        my ($fileid, $file) = each( %{$result->{query}->{pages}} );
 451        # If not defined it means there is no revision of the file for
 452        # given timestamp.
 453        if (defined($file->{imageinfo})) {
 454                $mediafile{title} = $filename;
 455
 456                my $fileinfo = pop(@{$file->{imageinfo}});
 457                $mediafile{timestamp} = $fileinfo->{timestamp};
 458                # Mediawiki::API's download function doesn't support https URLs
 459                # and can't download old versions of files.
 460                print STDERR "\tDownloading file $mediafile{title}, version $mediafile{timestamp}\n";
 461                $mediafile{content} = download_mw_mediafile($fileinfo->{url});
 462        }
 463        return %mediafile;
 464}
 465
 466sub download_mw_mediafile {
 467        my $download_url = shift;
 468
 469        my $response = $mediawiki->{ua}->get($download_url);
 470        if ($response->code == 200) {
 471                return $response->decoded_content;
 472        } else {
 473                print STDERR "Error downloading mediafile from :\n";
 474                print STDERR "URL: $download_url\n";
 475                print STDERR "Server response: " . $response->code . " " . $response->message . "\n";
 476                exit 1;
 477        }
 478}
 479
 480sub get_last_local_revision {
 481        # Get note regarding last mediawiki revision
 482        my $note = run_git("notes --ref=$remotename/mediawiki show refs/mediawiki/$remotename/master 2>/dev/null");
 483        my @note_info = split(/ /, $note);
 484
 485        my $lastrevision_number;
 486        if (!(defined($note_info[0]) && $note_info[0] eq "mediawiki_revision:")) {
 487                print STDERR "No previous mediawiki revision found";
 488                $lastrevision_number = 0;
 489        } else {
 490                # Notes are formatted : mediawiki_revision: #number
 491                $lastrevision_number = $note_info[1];
 492                chomp($lastrevision_number);
 493                print STDERR "Last local mediawiki revision found is $lastrevision_number";
 494        }
 495        return $lastrevision_number;
 496}
 497
 498# Get the last remote revision without taking in account which pages are
 499# tracked or not. This function makes a single request to the wiki thus
 500# avoid a loop onto all tracked pages. This is useful for the fetch-by-rev
 501# option.
 502sub get_last_global_remote_rev {
 503        mw_connect_maybe();
 504
 505        my $query = {
 506                action => 'query',
 507                list => 'recentchanges',
 508                prop => 'revisions',
 509                rclimit => '1',
 510                rcdir => 'older',
 511        };
 512        my $result = $mediawiki->api($query);
 513        return $result->{query}->{recentchanges}[0]->{revid};
 514}
 515
 516# Get the last remote revision concerning the tracked pages and the tracked
 517# categories.
 518sub get_last_remote_revision {
 519        mw_connect_maybe();
 520
 521        my %pages_hash = get_mw_pages();
 522        my @pages = values(%pages_hash);
 523
 524        my $max_rev_num = 0;
 525
 526        print STDERR "Getting last revision id on tracked pages...\n";
 527
 528        foreach my $page (@pages) {
 529                my $id = $page->{pageid};
 530
 531                my $query = {
 532                        action => 'query',
 533                        prop => 'revisions',
 534                        rvprop => 'ids|timestamp',
 535                        pageids => $id,
 536                };
 537
 538                my $result = $mediawiki->api($query);
 539
 540                my $lastrev = pop(@{$result->{query}->{pages}->{$id}->{revisions}});
 541
 542                $basetimestamps{$lastrev->{revid}} = $lastrev->{timestamp};
 543
 544                $max_rev_num = ($lastrev->{revid} > $max_rev_num ? $lastrev->{revid} : $max_rev_num);
 545        }
 546
 547        print STDERR "Last remote revision found is $max_rev_num.\n";
 548        return $max_rev_num;
 549}
 550
 551# Clean content before sending it to MediaWiki
 552sub mediawiki_clean {
 553        my $string = shift;
 554        my $page_created = shift;
 555        # Mediawiki does not allow blank space at the end of a page and ends with a single \n.
 556        # This function right trims a string and adds a \n at the end to follow this rule
 557        $string =~ s/\s+$//;
 558        if ($string eq "" && $page_created) {
 559                # Creating empty pages is forbidden.
 560                $string = EMPTY_CONTENT;
 561        }
 562        return $string."\n";
 563}
 564
 565# Filter applied on MediaWiki data before adding them to Git
 566sub mediawiki_smudge {
 567        my $string = shift;
 568        if ($string eq EMPTY_CONTENT) {
 569                $string = "";
 570        }
 571        # This \n is important. This is due to mediawiki's way to handle end of files.
 572        return $string."\n";
 573}
 574
 575sub mediawiki_clean_filename {
 576        my $filename = shift;
 577        $filename =~ s{@{[SLASH_REPLACEMENT]}}{/}g;
 578        # [, ], |, {, and } are forbidden by MediaWiki, even URL-encoded.
 579        # Do a variant of URL-encoding, i.e. looks like URL-encoding,
 580        # but with _ added to prevent MediaWiki from thinking this is
 581        # an actual special character.
 582        $filename =~ s/[\[\]\{\}\|]/sprintf("_%%_%x", ord($&))/ge;
 583        # If we use the uri escape before
 584        # we should unescape here, before anything
 585
 586        return $filename;
 587}
 588
 589sub mediawiki_smudge_filename {
 590        my $filename = shift;
 591        $filename =~ s{/}{@{[SLASH_REPLACEMENT]}}g;
 592        $filename =~ s/ /_/g;
 593        # Decode forbidden characters encoded in mediawiki_clean_filename
 594        $filename =~ s/_%_([0-9a-fA-F][0-9a-fA-F])/sprintf("%c", hex($1))/ge;
 595        return $filename;
 596}
 597
 598sub literal_data {
 599        my ($content) = @_;
 600        print STDOUT "data ", bytes::length($content), "\n", $content;
 601        return;
 602}
 603
 604sub literal_data_raw {
 605        # Output possibly binary content.
 606        my ($content) = @_;
 607        # Avoid confusion between size in bytes and in characters
 608        utf8::downgrade($content);
 609        binmode STDOUT, ":raw";
 610        print STDOUT "data ", bytes::length($content), "\n", $content;
 611        binmode STDOUT, ":encoding(UTF-8)";
 612        return;
 613}
 614
 615sub mw_capabilities {
 616        # Revisions are imported to the private namespace
 617        # refs/mediawiki/$remotename/ by the helper and fetched into
 618        # refs/remotes/$remotename later by fetch.
 619        print STDOUT "refspec refs/heads/*:refs/mediawiki/$remotename/*\n";
 620        print STDOUT "import\n";
 621        print STDOUT "list\n";
 622        print STDOUT "push\n";
 623        print STDOUT "\n";
 624        return;
 625}
 626
 627sub mw_list {
 628        # MediaWiki do not have branches, we consider one branch arbitrarily
 629        # called master, and HEAD pointing to it.
 630        print STDOUT "? refs/heads/master\n";
 631        print STDOUT "\@refs/heads/master HEAD\n";
 632        print STDOUT "\n";
 633        return;
 634}
 635
 636sub mw_option {
 637        print STDERR "remote-helper command 'option $_[0]' not yet implemented\n";
 638        print STDOUT "unsupported\n";
 639        return;
 640}
 641
 642sub fetch_mw_revisions_for_page {
 643        my $page = shift;
 644        my $id = shift;
 645        my $fetch_from = shift;
 646        my @page_revs = ();
 647        my $query = {
 648                action => 'query',
 649                prop => 'revisions',
 650                rvprop => 'ids',
 651                rvdir => 'newer',
 652                rvstartid => $fetch_from,
 653                rvlimit => 500,
 654                pageids => $id,
 655        };
 656
 657        my $revnum = 0;
 658        # Get 500 revisions at a time due to the mediawiki api limit
 659        while (1) {
 660                my $result = $mediawiki->api($query);
 661
 662                # Parse each of those 500 revisions
 663                foreach my $revision (@{$result->{query}->{pages}->{$id}->{revisions}}) {
 664                        my $page_rev_ids;
 665                        $page_rev_ids->{pageid} = $page->{pageid};
 666                        $page_rev_ids->{revid} = $revision->{revid};
 667                        push(@page_revs, $page_rev_ids);
 668                        $revnum++;
 669                }
 670                last unless $result->{'query-continue'};
 671                $query->{rvstartid} = $result->{'query-continue'}->{revisions}->{rvstartid};
 672        }
 673        if ($shallow_import && @page_revs) {
 674                print STDERR "  Found 1 revision (shallow import).\n";
 675                @page_revs = sort {$b->{revid} <=> $a->{revid}} (@page_revs);
 676                return $page_revs[0];
 677        }
 678        print STDERR "  Found ", $revnum, " revision(s).\n";
 679        return @page_revs;
 680}
 681
 682sub fetch_mw_revisions {
 683        my $pages = shift; my @pages = @{$pages};
 684        my $fetch_from = shift;
 685
 686        my @revisions = ();
 687        my $n = 1;
 688        foreach my $page (@pages) {
 689                my $id = $page->{pageid};
 690
 691                print STDERR "page $n/", scalar(@pages), ": ". $page->{title} ."\n";
 692                $n++;
 693                my @page_revs = fetch_mw_revisions_for_page($page, $id, $fetch_from);
 694                @revisions = (@page_revs, @revisions);
 695        }
 696
 697        return ($n, @revisions);
 698}
 699
 700sub fe_escape_path {
 701    my $path = shift;
 702    $path =~ s/\\/\\\\/g;
 703    $path =~ s/"/\\"/g;
 704    $path =~ s/\n/\\n/g;
 705    return '"' . $path . '"';
 706}
 707
 708sub import_file_revision {
 709        my $commit = shift;
 710        my %commit = %{$commit};
 711        my $full_import = shift;
 712        my $n = shift;
 713        my $mediafile = shift;
 714        my %mediafile;
 715        if ($mediafile) {
 716                %mediafile = %{$mediafile};
 717        }
 718
 719        my $title = $commit{title};
 720        my $comment = $commit{comment};
 721        my $content = $commit{content};
 722        my $author = $commit{author};
 723        my $date = $commit{date};
 724
 725        print STDOUT "commit refs/mediawiki/$remotename/master\n";
 726        print STDOUT "mark :$n\n";
 727        print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 728        literal_data($comment);
 729
 730        # If it's not a clone, we need to know where to start from
 731        if (!$full_import && $n == 1) {
 732                print STDOUT "from refs/mediawiki/$remotename/master^0\n";
 733        }
 734        if ($content ne DELETED_CONTENT) {
 735                print STDOUT "M 644 inline " .
 736                    fe_escape_path($title . ".mw") . "\n";
 737                literal_data($content);
 738                if (%mediafile) {
 739                        print STDOUT "M 644 inline "
 740                            . fe_escape_path($mediafile{title}) . "\n";
 741                        literal_data_raw($mediafile{content});
 742                }
 743                print STDOUT "\n\n";
 744        } else {
 745                print STDOUT "D " . fe_escape_path($title . ".mw") . "\n";
 746        }
 747
 748        # mediawiki revision number in the git note
 749        if ($full_import && $n == 1) {
 750                print STDOUT "reset refs/notes/$remotename/mediawiki\n";
 751        }
 752        print STDOUT "commit refs/notes/$remotename/mediawiki\n";
 753        print STDOUT "committer $author <$author\@$wiki_name> ", $date->epoch, " +0000\n";
 754        literal_data("Note added by git-mediawiki during import");
 755        if (!$full_import && $n == 1) {
 756                print STDOUT "from refs/notes/$remotename/mediawiki^0\n";
 757        }
 758        print STDOUT "N inline :$n\n";
 759        literal_data("mediawiki_revision: " . $commit{mw_revision});
 760        print STDOUT "\n\n";
 761        return;
 762}
 763
 764# parse a sequence of
 765# <cmd> <arg1>
 766# <cmd> <arg2>
 767# \n
 768# (like batch sequence of import and sequence of push statements)
 769sub get_more_refs {
 770        my $cmd = shift;
 771        my @refs;
 772        while (1) {
 773                my $line = <STDIN>;
 774                if ($line =~ /^$cmd (.*)$/) {
 775                        push(@refs, $1);
 776                } elsif ($line eq "\n") {
 777                        return @refs;
 778                } else {
 779                        die("Invalid command in a '$cmd' batch: $_\n");
 780                }
 781        }
 782        return;
 783}
 784
 785sub mw_import {
 786        # multiple import commands can follow each other.
 787        my @refs = (shift, get_more_refs("import"));
 788        foreach my $ref (@refs) {
 789                mw_import_ref($ref);
 790        }
 791        print STDOUT "done\n";
 792        return;
 793}
 794
 795sub mw_import_ref {
 796        my $ref = shift;
 797        # The remote helper will call "import HEAD" and
 798        # "import refs/heads/master".
 799        # Since HEAD is a symbolic ref to master (by convention,
 800        # followed by the output of the command "list" that we gave),
 801        # we don't need to do anything in this case.
 802        if ($ref eq "HEAD") {
 803                return;
 804        }
 805
 806        mw_connect_maybe();
 807
 808        print STDERR "Searching revisions...\n";
 809        my $last_local = get_last_local_revision();
 810        my $fetch_from = $last_local + 1;
 811        if ($fetch_from == 1) {
 812                print STDERR ", fetching from beginning.\n";
 813        } else {
 814                print STDERR ", fetching from here.\n";
 815        }
 816
 817        my $n = 0;
 818        if ($fetch_strategy eq "by_rev") {
 819                print STDERR "Fetching & writing export data by revs...\n";
 820                $n = mw_import_ref_by_revs($fetch_from);
 821        } elsif ($fetch_strategy eq "by_page") {
 822                print STDERR "Fetching & writing export data by pages...\n";
 823                $n = mw_import_ref_by_pages($fetch_from);
 824        } else {
 825                print STDERR "fatal: invalid fetch strategy \"$fetch_strategy\".\n";
 826                print STDERR "Check your configuration variables remote.$remotename.fetchStrategy and mediawiki.fetchStrategy\n";
 827                exit 1;
 828        }
 829
 830        if ($fetch_from == 1 && $n == 0) {
 831                print STDERR "You appear to have cloned an empty MediaWiki.\n";
 832                # Something has to be done remote-helper side. If nothing is done, an error is
 833                # thrown saying that HEAD is referring to unknown object 0000000000000000000
 834                # and the clone fails.
 835        }
 836        return;
 837}
 838
 839sub mw_import_ref_by_pages {
 840
 841        my $fetch_from = shift;
 842        my %pages_hash = get_mw_pages();
 843        my @pages = values(%pages_hash);
 844
 845        my ($n, @revisions) = fetch_mw_revisions(\@pages, $fetch_from);
 846
 847        @revisions = sort {$a->{revid} <=> $b->{revid}} @revisions;
 848        my @revision_ids = map { $_->{revid} } @revisions;
 849
 850        return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 851}
 852
 853sub mw_import_ref_by_revs {
 854
 855        my $fetch_from = shift;
 856        my %pages_hash = get_mw_pages();
 857
 858        my $last_remote = get_last_global_remote_rev();
 859        my @revision_ids = $fetch_from..$last_remote;
 860        return mw_import_revids($fetch_from, \@revision_ids, \%pages_hash);
 861}
 862
 863# Import revisions given in second argument (array of integers).
 864# Only pages appearing in the third argument (hash indexed by page titles)
 865# will be imported.
 866sub mw_import_revids {
 867        my $fetch_from = shift;
 868        my $revision_ids = shift;
 869        my $pages = shift;
 870
 871        my $n = 0;
 872        my $n_actual = 0;
 873        my $last_timestamp = 0; # Placeholer in case $rev->timestamp is undefined
 874
 875        foreach my $pagerevid (@$revision_ids) {
 876                # Count page even if we skip it, since we display
 877                # $n/$total and $total includes skipped pages.
 878                $n++;
 879
 880                # fetch the content of the pages
 881                my $query = {
 882                        action => 'query',
 883                        prop => 'revisions',
 884                        rvprop => 'content|timestamp|comment|user|ids',
 885                        revids => $pagerevid,
 886                };
 887
 888                my $result = $mediawiki->api($query);
 889
 890                if (!$result) {
 891                        die "Failed to retrieve modified page for revision $pagerevid\n";
 892                }
 893
 894                if (defined($result->{query}->{badrevids}->{$pagerevid})) {
 895                        # The revision id does not exist on the remote wiki.
 896                        next;
 897                }
 898
 899                if (!defined($result->{query}->{pages})) {
 900                        die "Invalid revision $pagerevid.\n";
 901                }
 902
 903                my @result_pages = values(%{$result->{query}->{pages}});
 904                my $result_page = $result_pages[0];
 905                my $rev = $result_pages[0]->{revisions}->[0];
 906
 907                my $page_title = $result_page->{title};
 908
 909                if (!exists($pages->{$page_title})) {
 910                        print STDERR "$n/", scalar(@$revision_ids),
 911                                ": Skipping revision #$rev->{revid} of $page_title\n";
 912                        next;
 913                }
 914
 915                $n_actual++;
 916
 917                my %commit;
 918                $commit{author} = $rev->{user} || 'Anonymous';
 919                $commit{comment} = $rev->{comment} || EMPTY_MESSAGE;
 920                $commit{title} = mediawiki_smudge_filename($page_title);
 921                $commit{mw_revision} = $rev->{revid};
 922                $commit{content} = mediawiki_smudge($rev->{'*'});
 923
 924                if (!defined($rev->{timestamp})) {
 925                        $last_timestamp++;
 926                } else {
 927                        $last_timestamp = $rev->{timestamp};
 928                }
 929                $commit{date} = DateTime::Format::ISO8601->parse_datetime($last_timestamp);
 930
 931                # Differentiates classic pages and media files.
 932                my ($namespace, $filename) = $page_title =~ /^([^:]*):(.*)$/;
 933                my %mediafile;
 934                if ($namespace) {
 935                        my $id = get_mw_namespace_id($namespace);
 936                        if ($id && $id == get_mw_namespace_id("File")) {
 937                                %mediafile = get_mw_mediafile_for_page_revision($filename, $rev->{timestamp});
 938                        }
 939                }
 940                # If this is a revision of the media page for new version
 941                # of a file do one common commit for both file and media page.
 942                # Else do commit only for that page.
 943                print STDERR "$n/", scalar(@$revision_ids), ": Revision #$rev->{revid} of $commit{title}\n";
 944                import_file_revision(\%commit, ($fetch_from == 1), $n_actual, \%mediafile);
 945        }
 946
 947        return $n_actual;
 948}
 949
 950sub error_non_fast_forward {
 951        my $advice = run_git("config --bool advice.pushNonFastForward");
 952        chomp($advice);
 953        if ($advice ne "false") {
 954                # Native git-push would show this after the summary.
 955                # We can't ask it to display it cleanly, so print it
 956                # ourselves before.
 957                print STDERR "To prevent you from losing history, non-fast-forward updates were rejected\n";
 958                print STDERR "Merge the remote changes (e.g. 'git pull') before pushing again. See the\n";
 959                print STDERR "'Note about fast-forwards' section of 'git push --help' for details.\n";
 960        }
 961        print STDOUT "error $_[0] \"non-fast-forward\"\n";
 962        return 0;
 963}
 964
 965sub mw_upload_file {
 966        my $complete_file_name = shift;
 967        my $new_sha1 = shift;
 968        my $extension = shift;
 969        my $file_deleted = shift;
 970        my $summary = shift;
 971        my $newrevid;
 972        my $path = "File:" . $complete_file_name;
 973        my %hashFiles = get_allowed_file_extensions();
 974        if (!exists($hashFiles{$extension})) {
 975                print STDERR "$complete_file_name is not a permitted file on this wiki.\n";
 976                print STDERR "Check the configuration of file uploads in your mediawiki.\n";
 977                return $newrevid;
 978        }
 979        # Deleting and uploading a file requires a priviledged user
 980        if ($file_deleted) {
 981                mw_connect_maybe();
 982                my $query = {
 983                        action => 'delete',
 984                        title => $path,
 985                        reason => $summary
 986                };
 987                if (!$mediawiki->edit($query)) {
 988                        print STDERR "Failed to delete file on remote wiki\n";
 989                        print STDERR "Check your permissions on the remote site. Error code:\n";
 990                        print STDERR $mediawiki->{error}->{code} . ':' . $mediawiki->{error}->{details};
 991                        exit 1;
 992                }
 993        } else {
 994                # Don't let perl try to interpret file content as UTF-8 => use "raw"
 995                my $content = run_git("cat-file blob $new_sha1", "raw");
 996                if ($content ne "") {
 997                        mw_connect_maybe();
 998                        $mediawiki->{config}->{upload_url} =
 999                                "$url/index.php/Special:Upload";
1000                        $mediawiki->edit({
1001                                action => 'upload',
1002                                filename => $complete_file_name,
1003                                comment => $summary,
1004                                file => [undef,
1005                                         $complete_file_name,
1006                                         Content => $content],
1007                                ignorewarnings => 1,
1008                        }, {
1009                                skip_encoding => 1
1010                        } ) || die $mediawiki->{error}->{code} . ':'
1011                                 . $mediawiki->{error}->{details} . "\n";
1012                        my $last_file_page = $mediawiki->get_page({title => $path});
1013                        $newrevid = $last_file_page->{revid};
1014                        print STDERR "Pushed file: $new_sha1 - $complete_file_name.\n";
1015                } else {
1016                        print STDERR "Empty file $complete_file_name not pushed.\n";
1017                }
1018        }
1019        return $newrevid;
1020}
1021
1022sub mw_push_file {
1023        my $diff_info = shift;
1024        # $diff_info contains a string in this format:
1025        # 100644 100644 <sha1_of_blob_before_commit> <sha1_of_blob_now> <status>
1026        my @diff_info_split = split(/[ \t]/, $diff_info);
1027
1028        # Filename, including .mw extension
1029        my $complete_file_name = shift;
1030        # Commit message
1031        my $summary = shift;
1032        # MediaWiki revision number. Keep the previous one by default,
1033        # in case there's no edit to perform.
1034        my $oldrevid = shift;
1035        my $newrevid;
1036
1037        if ($summary eq EMPTY_MESSAGE) {
1038                $summary = '';
1039        }
1040
1041        my $new_sha1 = $diff_info_split[3];
1042        my $old_sha1 = $diff_info_split[2];
1043        my $page_created = ($old_sha1 eq NULL_SHA1);
1044        my $page_deleted = ($new_sha1 eq NULL_SHA1);
1045        $complete_file_name = mediawiki_clean_filename($complete_file_name);
1046
1047        my ($title, $extension) = $complete_file_name =~ /^(.*)\.([^\.]*)$/;
1048        if (!defined($extension)) {
1049                $extension = "";
1050        }
1051        if ($extension eq "mw") {
1052                my $ns = get_mw_namespace_id_for_page($complete_file_name);
1053                if ($ns && $ns == get_mw_namespace_id("File") && (!$export_media)) {
1054                        print STDERR "Ignoring media file related page: $complete_file_name\n";
1055                        return ($oldrevid, "ok");
1056                }
1057                my $file_content;
1058                if ($page_deleted) {
1059                        # Deleting a page usually requires
1060                        # special privileges. A common
1061                        # convention is to replace the page
1062                        # with this content instead:
1063                        $file_content = DELETED_CONTENT;
1064                } else {
1065                        $file_content = run_git("cat-file blob $new_sha1");
1066                }
1067
1068                mw_connect_maybe();
1069
1070                my $result = $mediawiki->edit( {
1071                        action => 'edit',
1072                        summary => $summary,
1073                        title => $title,
1074                        basetimestamp => $basetimestamps{$oldrevid},
1075                        text => mediawiki_clean($file_content, $page_created),
1076                                  }, {
1077                                          skip_encoding => 1 # Helps with names with accentuated characters
1078                                  });
1079                if (!$result) {
1080                        if ($mediawiki->{error}->{code} == 3) {
1081                                # edit conflicts, considered as non-fast-forward
1082                                print STDERR 'Warning: Error ' .
1083                                    $mediawiki->{error}->{code} .
1084                                    ' from mediwiki: ' . $mediawiki->{error}->{details} .
1085                                    ".\n";
1086                                return ($oldrevid, "non-fast-forward");
1087                        } else {
1088                                # Other errors. Shouldn't happen => just die()
1089                                die 'Fatal: Error ' .
1090                                    $mediawiki->{error}->{code} .
1091                                    ' from mediwiki: ' . $mediawiki->{error}->{details} . "\n";
1092                        }
1093                }
1094                $newrevid = $result->{edit}->{newrevid};
1095                print STDERR "Pushed file: $new_sha1 - $title\n";
1096        } elsif ($export_media) {
1097                $newrevid = mw_upload_file($complete_file_name, $new_sha1,
1098                                           $extension, $page_deleted,
1099                                           $summary);
1100        } else {
1101                print STDERR "Ignoring media file $title\n";
1102        }
1103        $newrevid = ($newrevid or $oldrevid);
1104        return ($newrevid, "ok");
1105}
1106
1107sub mw_push {
1108        # multiple push statements can follow each other
1109        my @refsspecs = (shift, get_more_refs("push"));
1110        my $pushed;
1111        for my $refspec (@refsspecs) {
1112                my ($force, $local, $remote) = $refspec =~ /^(\+)?([^:]*):([^:]*)$/
1113                    or die("Invalid refspec for push. Expected <src>:<dst> or +<src>:<dst>\n");
1114                if ($force) {
1115                        print STDERR "Warning: forced push not allowed on a MediaWiki.\n";
1116                }
1117                if ($local eq "") {
1118                        print STDERR "Cannot delete remote branch on a MediaWiki\n";
1119                        print STDOUT "error $remote cannot delete\n";
1120                        next;
1121                }
1122                if ($remote ne "refs/heads/master") {
1123                        print STDERR "Only push to the branch 'master' is supported on a MediaWiki\n";
1124                        print STDOUT "error $remote only master allowed\n";
1125                        next;
1126                }
1127                if (mw_push_revision($local, $remote)) {
1128                        $pushed = 1;
1129                }
1130        }
1131
1132        # Notify Git that the push is done
1133        print STDOUT "\n";
1134
1135        if ($pushed && $dumb_push) {
1136                print STDERR "Just pushed some revisions to MediaWiki.\n";
1137                print STDERR "The pushed revisions now have to be re-imported, and your current branch\n";
1138                print STDERR "needs to be updated with these re-imported commits. You can do this with\n";
1139                print STDERR "\n";
1140                print STDERR "  git pull --rebase\n";
1141                print STDERR "\n";
1142        }
1143        return;
1144}
1145
1146sub mw_push_revision {
1147        my $local = shift;
1148        my $remote = shift; # actually, this has to be "refs/heads/master" at this point.
1149        my $last_local_revid = get_last_local_revision();
1150        print STDERR ".\n"; # Finish sentence started by get_last_local_revision()
1151        my $last_remote_revid = get_last_remote_revision();
1152        my $mw_revision = $last_remote_revid;
1153
1154        # Get sha1 of commit pointed by local HEAD
1155        my $HEAD_sha1 = run_git("rev-parse $local 2>/dev/null"); chomp($HEAD_sha1);
1156        # Get sha1 of commit pointed by remotes/$remotename/master
1157        my $remoteorigin_sha1 = run_git("rev-parse refs/remotes/$remotename/master 2>/dev/null");
1158        chomp($remoteorigin_sha1);
1159
1160        if ($last_local_revid > 0 &&
1161            $last_local_revid < $last_remote_revid) {
1162                return error_non_fast_forward($remote);
1163        }
1164
1165        if ($HEAD_sha1 eq $remoteorigin_sha1) {
1166                # nothing to push
1167                return 0;
1168        }
1169
1170        # Get every commit in between HEAD and refs/remotes/origin/master,
1171        # including HEAD and refs/remotes/origin/master
1172        my @commit_pairs = ();
1173        if ($last_local_revid > 0) {
1174                my $parsed_sha1 = $remoteorigin_sha1;
1175                # Find a path from last MediaWiki commit to pushed commit
1176                print STDERR "Computing path from local to remote ...\n";
1177                my @local_ancestry = split(/\n/, run_git("rev-list --boundary --parents $local ^$parsed_sha1"));
1178                my %local_ancestry;
1179                foreach my $line (@local_ancestry) {
1180                        if (my ($child, $parents) = $line =~ /^-?([a-f0-9]+) ([a-f0-9 ]+)/) {
1181                                foreach my $parent (split(/ /, $parents)) {
1182                                        $local_ancestry{$parent} = $child;
1183                                }
1184                        } elsif (!$line =~ /^([a-f0-9]+)/) {
1185                                die "Unexpected output from git rev-list: $line\n";
1186                        }
1187                }
1188                while ($parsed_sha1 ne $HEAD_sha1) {
1189                        my $child = $local_ancestry{$parsed_sha1};
1190                        if (!$child) {
1191                                printf STDERR "Cannot find a path in history from remote commit to last commit\n";
1192                                return error_non_fast_forward($remote);
1193                        }
1194                        push(@commit_pairs, [$parsed_sha1, $child]);
1195                        $parsed_sha1 = $child;
1196                }
1197        } else {
1198                # No remote mediawiki revision. Export the whole
1199                # history (linearized with --first-parent)
1200                print STDERR "Warning: no common ancestor, pushing complete history\n";
1201                my $history = run_git("rev-list --first-parent --children $local");
1202                my @history = split(/\n/, $history);
1203                @history = @history[1..$#history];
1204                foreach my $line (reverse @history) {
1205                        my @commit_info_split = split(/[ \n]/, $line);
1206                        push(@commit_pairs, \@commit_info_split);
1207                }
1208        }
1209
1210        foreach my $commit_info_split (@commit_pairs) {
1211                my $sha1_child = @{$commit_info_split}[0];
1212                my $sha1_commit = @{$commit_info_split}[1];
1213                my $diff_infos = run_git("diff-tree -r --raw -z $sha1_child $sha1_commit");
1214                # TODO: we could detect rename, and encode them with a #redirect on the wiki.
1215                # TODO: for now, it's just a delete+add
1216                my @diff_info_list = split(/\0/, $diff_infos);
1217                # Keep the subject line of the commit message as mediawiki comment for the revision
1218                my $commit_msg = run_git("log --no-walk --format=\"%s\" $sha1_commit");
1219                chomp($commit_msg);
1220                # Push every blob
1221                while (@diff_info_list) {
1222                        my $status;
1223                        # git diff-tree -z gives an output like
1224                        # <metadata>\0<filename1>\0
1225                        # <metadata>\0<filename2>\0
1226                        # and we've split on \0.
1227                        my $info = shift(@diff_info_list);
1228                        my $file = shift(@diff_info_list);
1229                        ($mw_revision, $status) = mw_push_file($info, $file, $commit_msg, $mw_revision);
1230                        if ($status eq "non-fast-forward") {
1231                                # we may already have sent part of the
1232                                # commit to MediaWiki, but it's too
1233                                # late to cancel it. Stop the push in
1234                                # the middle, but still give an
1235                                # accurate error message.
1236                                return error_non_fast_forward($remote);
1237                        }
1238                        if ($status ne "ok") {
1239                                die("Unknown error from mw_push_file()\n");
1240                        }
1241                }
1242                unless ($dumb_push) {
1243                        run_git("notes --ref=$remotename/mediawiki add -f -m \"mediawiki_revision: $mw_revision\" $sha1_commit");
1244                        run_git("update-ref -m \"Git-MediaWiki push\" refs/mediawiki/$remotename/master $sha1_commit $sha1_child");
1245                }
1246        }
1247
1248        print STDOUT "ok $remote\n";
1249        return 1;
1250}
1251
1252sub get_allowed_file_extensions {
1253        mw_connect_maybe();
1254
1255        my $query = {
1256                action => 'query',
1257                meta => 'siteinfo',
1258                siprop => 'fileextensions'
1259                };
1260        my $result = $mediawiki->api($query);
1261        my @file_extensions = map { $_->{ext}} @{$result->{query}->{fileextensions}};
1262        my %hashFile = map { $_ => 1 } @file_extensions;
1263
1264        return %hashFile;
1265}
1266
1267# In memory cache for MediaWiki namespace ids.
1268my %namespace_id;
1269
1270# Namespaces whose id is cached in the configuration file
1271# (to avoid duplicates)
1272my %cached_mw_namespace_id;
1273
1274# Return MediaWiki id for a canonical namespace name.
1275# Ex.: "File", "Project".
1276sub get_mw_namespace_id {
1277        mw_connect_maybe();
1278        my $name = shift;
1279
1280        if (!exists $namespace_id{$name}) {
1281                # Look at configuration file, if the record for that namespace is
1282                # already cached. Namespaces are stored in form:
1283                # "Name_of_namespace:Id_namespace", ex.: "File:6".
1284                my @temp = split(/\n/, run_git("config --get-all remote."
1285                                                . $remotename .".namespaceCache"));
1286                chomp(@temp);
1287                foreach my $ns (@temp) {
1288                        my ($n, $id) = split(/:/, $ns);
1289                        if ($id eq 'notANameSpace') {
1290                                $namespace_id{$n} = {is_namespace => 0};
1291                        } else {
1292                                $namespace_id{$n} = {is_namespace => 1, id => $id};
1293                        }
1294                        $cached_mw_namespace_id{$n} = 1;
1295                }
1296        }
1297
1298        if (!exists $namespace_id{$name}) {
1299                print STDERR "Namespace $name not found in cache, querying the wiki ...\n";
1300                # NS not found => get namespace id from MW and store it in
1301                # configuration file.
1302                my $query = {
1303                        action => 'query',
1304                        meta => 'siteinfo',
1305                        siprop => 'namespaces'
1306                };
1307                my $result = $mediawiki->api($query);
1308
1309                while (my ($id, $ns) = each(%{$result->{query}->{namespaces}})) {
1310                        if (defined($ns->{id}) && defined($ns->{canonical})) {
1311                                $namespace_id{$ns->{canonical}} = {is_namespace => 1, id => $ns->{id}};
1312                                if ($ns->{'*'}) {
1313                                        # alias (e.g. french Fichier: as alias for canonical File:)
1314                                        $namespace_id{$ns->{'*'}} = {is_namespace => 1, id => $ns->{id}};
1315                                }
1316                        }
1317                }
1318        }
1319
1320        my $ns = $namespace_id{$name};
1321        my $id;
1322
1323        unless (defined $ns) {
1324                print STDERR "No such namespace $name on MediaWiki.\n";
1325                $ns = {is_namespace => 0};
1326                $namespace_id{$name} = $ns;
1327        }
1328
1329        if ($ns->{is_namespace}) {
1330                $id = $ns->{id};
1331        }
1332
1333        # Store "notANameSpace" as special value for inexisting namespaces
1334        my $store_id = ($id || 'notANameSpace');
1335
1336        # Store explicitely requested namespaces on disk
1337        if (!exists $cached_mw_namespace_id{$name}) {
1338                run_git("config --add remote.". $remotename
1339                        .".namespaceCache \"". $name .":". $store_id ."\"");
1340                $cached_mw_namespace_id{$name} = 1;
1341        }
1342        return $id;
1343}
1344
1345sub get_mw_namespace_id_for_page {
1346        my $namespace = shift;
1347        if ($namespace =~ /^([^:]*):/) {
1348                return get_mw_namespace_id($namespace);
1349        } else {
1350                return;
1351        }
1352}