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

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