--- a/bin/imager.compress	Tue Aug 16 14:17:50 2011 +0200
+++ b/bin/imager.compress	Tue Aug 16 14:44:45 2011 +0200
@@ -35,6 +35,10 @@
 	gunzip(\$zbuffer => \$buffer)
 	    or die $GunzipError;
 
+	if (!length($buffer)) {
+		warn "?? zero length after decompression: $_\n";
+		return;
+	}
 	return if length($zbuffer)/length($buffer) < THRESHOLD;
 
 	$tmp = File::Temp->new(DIR => ".", TEMPLATE => ".tmp-XXXXXX");