gs: work arround broken xref table pdfs

rebuilding the xref table does not work for pdfs with
compressed object streams. as a work arround, we skip
xref table verification and ignore wrong xref gen #
for gen 0 objects.

sys/lib/ghostscript/pdf_base.ps

@@ -412,11 +412,10 @@ pdfdict begin
 	(   **** Warning: wrong generation: )
       } ifelse
       2 index =string cvs concatstrings ( ) concatstrings	% put obj #
-      exch =string cvs concatstrings ( R\n) concatstrings	% put gen #
+      1 index =string cvs concatstrings ( R\n) concatstrings	% put gen #
       pdfformaterror			% Output warning message
-    } {					% Else QUIET ...
-      pop				% Pop generation umber
-    } ifelse false			% Return false if gen # not match
+    } if
+    0 eq
   } ifelse
 } bind def
 /R {		% <object#> <generation#> R <object>

sys/lib/ghostscript/pdf_main.ps

@@ -25,6 +25,8 @@ pdfdict begin
 % Patch in an obsolete variable used by some third-party software.
 /#? false def
 
+/NoVerifyXref true def
+
 % Test whether the current output device handles pdfmark.
 /.writepdfmarkdict 1 dict dup /pdfmark null put readonly def
 /.writepdfmarks {	% - .writepdfmarks <bool>