Merge branch 'cm/remote-mediawiki'

* cm/remote-mediawiki:
  git-remote-mediawiki: display message when launched directly

diff --cc contrib/mw-to-git/git-remote-mediawiki.perl
index 717387275cdb0fd7e4999503cd53261e11f851a1,9b71972fc7393b4d5ece06bedbe83e5a0ae14ad0..c1a967b3d14e87fedebd093c473e1d6f6eb4e94c
--- 1/contrib/mw-to-git/git-remote-mediawiki.perl
--- 2/contrib/mw-to-git/git-remote-mediawiki.perl
+++ b/contrib/mw-to-git/git-remote-mediawiki.perl
@@@ -157,6 -160,68 +161,17 @@@ while (<STDIN>) 
  
  ########################## Functions ##############################
  
 -## credential API management (generic functions)
 -
 -sub credential_read {
 -      my %credential;
 -      my $reader = shift;
 -      my $op = shift;
 -      while (<$reader>) {
 -              my ($key, $value) = /([^=]*)=(.*)/;
 -              if (not defined $key) {
 -                      die "ERROR receiving response from git credential $op:\n$_\n";
 -              }
 -              $credential{$key} = $value;
 -      }
 -      return %credential;
 -}
 -
 -sub credential_write {
 -      my $credential = shift;
 -      my $writer = shift;
 -      # url overwrites other fields, so it must come first
 -      print $writer "url=$credential->{url}\n" if exists $credential->{url};
 -      while (my ($key, $value) = each(%$credential) ) {
 -              if (length $value && $key ne 'url') {
 -                      print $writer "$key=$value\n";
 -              }
 -      }
 -}
 -
 -sub credential_run {
 -      my $op = shift;
 -      my $credential = shift;
 -      my $pid = open2(my $reader, my $writer, "git credential $op");
 -      credential_write($credential, $writer);
 -      print $writer "\n";
 -      close($writer);
 -
 -      if ($op eq "fill") {
 -              %$credential = credential_read($reader, $op);
 -      } else {
 -              if (<$reader>) {
 -                      die "ERROR while running git credential $op:\n$_";
 -              }
 -      }
 -      close($reader);
 -      waitpid($pid, 0);
 -      my $child_exit_status = $? >> 8;
 -      if ($child_exit_status != 0) {
 -              die "'git credential $op' failed with code $child_exit_status.";
 -      }
 -}
 -
+ ## error handling
+ sub exit_error_usage {
+       die "ERROR: git-remote-mediawiki module was not called with a correct number of\n" .
+           "parameters\n" .
+           "You may obtain this error because you attempted to run the git-remote-mediawiki\n" .
+             "module directly.\n" .
+           "This module can be used the following way:\n" .
+           "\tgit clone mediawiki://<address of a mediawiki>\n" .
+           "Then, use git commit, push and pull as with every normal git repository.\n";
+ }
+ 
  # MediaWiki API instance, created lazily.
  my $mediawiki;