From: Ken Sharp <ken.sharp@artifex.com>
Date: Fri, 21 Sep 2018 14:28:15 +0000 (+0100)
Subject: pdfwrite - fix DSC comment parsing

pdfwrite - fix DSC comment parsing

This may affect other DSC parsing utilities. For some reason double
comment (%%) marks are being interpreted 'sometimes' in gs_init.ps
as DSC comments. This only happens when reading the init files from disk
becuase the ROM file system strips comments.

Passing these to pdfwrite causes it to drop later DSC comments, such
as %%Title: and %%Creator: which meant the information wasn't being
embedded in the document information dictionary.

Fix by converting double %% to single % comments, document this in the
header of gs_init.ps.

https://git.ghostscript.com/?p=ghostpdl.git;a=commit;h=f31702b38fba21153e26c3417c838618e7cfd16f
---

diff -up ghostscript-9.07/Resource/Init/gs_init.ps.comment_fix ghostscript-9.07/Resource/Init/gs_init.ps
--- ghostscript-9.07/Resource/Init/gs_init.ps.comment_fix	2019-02-28 11:02:59.540694185 +0100
+++ ghostscript-9.07/Resource/Init/gs_init.ps	2019-02-28 11:05:31.182710227 +0100
@@ -20,6 +20,11 @@
 %	%% Replace <n> <file(s)>
 % indicate places where the next <n> lines should be replaced by
 % the contents of <file(s)>, when creating a single merged init file.
+%
+% For reasons not clear to me, some cases of %% are being treated as
+% DSC comments when (and only when) the resource files are disk based
+% This can kill DSC parsing for pdfwrite at least, so avoid using
+% double % comments in this file.
 
 % The interpreter can call out to PostScript code.  All procedures
 % called in this way, and no other procedures defined in these
@@ -2132,22 +2137,22 @@ SAFER { .setsafe } if
 
 /UndefinePostScriptOperators {
 
-  %% This list is of Display PostScript operators. We believe that Display PostScript
-  %% was never fully implemented and the only known user, GNUStep, is no longer
-  %% using it. So lets remove it.
+  % This list is of Display PostScript operators. We believe that Display PostScript
+  % was never fully implemented and the only known user, GNUStep, is no longer
+  % using it. So lets remove it.
   [
   /condition /currentcontext /detach /.fork /join /.localfork /lock /monitor /notify
   /wait /yield /.currentscreenphase /.setscreenphase /.image2 /eoviewclip /initviewclip
   /viewclip /viewclippath /defineusername
-  %% NeXT DPS extensions
+  % NeXT DPS extensions
   /currentalpha /setalpha /.alphaimage /composite /compositerect /dissolve /sizeimagebox /.sizeimageparams
   ]
   {systemdict exch .forceundef} forall
 
-  %% This list is of operators which no longer appear to be used, and which we do not believe
-  %% to have any real use. For now we will undefine the operstors so they cannot easily be used
-  %% but can be easily restored (just delete the name from the list in the array). In future
-  %% we may remove the operator and the code implementation entirely.
+  % This list is of operators which no longer appear to be used, and which we do not believe
+  % to have any real use. For now we will undefine the operstors so they cannot easily be used
+  % but can be easily restored (just delete the name from the list in the array). In future
+  % we may remove the operator and the code implementation entirely.
   [
   /.bitadd /.charboxpath /.cond /.runandhide /.popdevicefilter
   /.execfile /.filenamesplit /.file_name_parent
@@ -2156,15 +2161,15 @@ SAFER { .setsafe } if
   /.currentlimitclamp /.dotorientation /.setaccuratecurves /.setcurvejoin /.setdashadapt /.setdotorientation
   /.setlimitclamp /.currentscreenlevels /.dashpath /.pathbbox /.identeq /.identne /.tokenexec /.forgetsave /.pantonecallback
 
-  %% Used by our own test suite files
-  %%/.setdotlength % Bug687720.ps
+  % Used by our own test suite files
+  %/.setdotlength % Bug687720.ps
   ]
   {systemdict exch .forceundef} forall
 
-  %% This list of operators are used internally by various parts of the Ghostscript startup code.
-  %% Since each operator is a potential security vulnerability, and any operator listed here
-  %% is not required once the initislisation is complete and functions are bound, we undefine
-  %% the ones that aren't needed at runtime.
+  % This list of operators are used internally by various parts of the Ghostscript startup code.
+  % Since each operator is a potential security vulnerability, and any operator listed here
+  % is not required once the initislisation is complete and functions are bound, we undefine
+  % the ones that aren't needed at runtime.
   [
   /.callinstall /.callbeginpage /.callendpage
   /.currentstackprotect /.setstackprotect /.errorexec /.finderrorobject /.installsystemnames /.bosobject /.fontbbox
@@ -2236,10 +2241,10 @@ SAFER { .setsafe } if
 } .bind executeonly def % must be bound and hidden for .forceundef
 
 /UndefinePDFOperators {
-  %% This list of operators are used internally by various parts of the Ghostscript PDF interpreter.
-  %% Since each operator is a potential security vulnerability, and any operator listed here
-  %% is not required once the initislisation is complete and functions are bound, we undefine
-  %% the ones that aren't needed at runtime.
+  % This list of operators are used internally by various parts of the Ghostscript PDF interpreter.
+  % Since each operator is a potential security vulnerability, and any operator listed here
+  % is not required once the initislisation is complete and functions are bound, we undefine
+  % the ones that aren't needed at runtime.
   [
   /.pdfawidthshow /.pdfwidthshow
   /.setfillcolor /.setfillcolorspace /.setstrokecolor /.setstrokecolorspace /.currentrenderingintent /.setrenderingintent
@@ -2380,8 +2385,8 @@ currentdict /.shadingtypes .undef
 currentdict /.wheredict .undef
 currentdict /.renderingintentdict .undef
 
-%% If we are using DELAYBIND we have to defer the undefinition
-%% until .bindnow.
+% If we are using DELAYBIND we have to defer the undefinition
+% until .bindnow.
 DELAYBIND not {
   SAFER {
     //systemdict /SAFERUndefinePostScriptOperators get exec
@@ -2408,7 +2413,7 @@ systemdict /superexec .knownget {
   systemdict /superexec .undef
 } if
 
-%% Can't remove this one until the last minute :-)
+% Can't remove this one until the last minute :-)
 systemdict /.undef .undef
 
 WRITESYSTEMDICT not { systemdict readonly pop } if