websetup: If setup fails, restore old setup file.

IkiWiki/Plugin/websetup.pm

@@ -403,6 +403,7 @@ sub showform ($$) {
 			$form->reset(0); # doesn't really make sense here
 		}
 		else {
+			my $oldsetup=readfile($config{setupfile});
 			IkiWiki::Setup::dump($config{setupfile});
 
 			IkiWiki::saveindex();
@@ -432,9 +433,12 @@ sub showform ($$) {
 			print "\n<\/pre>";
 			if ($ret != 0) {
 				print '<p class="error">'.
-					sprintf(gettext("<p class=\"error\">Error: %s exited nonzero (%s)"),
+					sprintf(gettext("Error: %s exited nonzero (%s). Discarding setup changes."),
 						join(" ", @command), $ret).
 					'</p>';
+				open(OUT, ">", $config{setupfile}) || error("$config{setupfile}: $!");
+				print OUT $oldsetup;
+				close OUT;
 			}
 
 			print $tail;

debian/changelog

@@ -6,6 +6,7 @@ ikiwiki (3.11) UNRELEASED; urgency=low
     error can be printed at that point if it's not available,
     allowing the admin to see it during wiki setup.
     Closes: #520015
+  * websetup: If setup fails, restore old setup file.
 
  -- Joey Hess <joeyh@debian.org>  Tue, 21 Apr 2009 21:41:38 -0400