Re: Fix for 687277, /undefined in token

IMO Ray should review it, but I'd like to bring some comments.

1. A separate user parameter looks fine, because PDFScanRules
looks made for a specific purpose. The important thing is
that PDFScanRules is being set on a special event.

2. Please ensure that NoImmediateEval is being properly
reset after a document completes or terminates by an error.

3. Please test with ///////////////////////////// .

Igor.


----- Original Message ----- 
From: "Alex Cherepanov" <[email protected]>
To: <[email protected]>
Sent: Tuesday, February 03, 2004 9:26 AM
Subject: [gs-code-review] Fix for 687277, /undefined in token


> Log message:
> Disable immediately evaluated named during PDF scanning because Acrobat
> Distiller for 5.0.5 for Mac generates PDF files that assume //Foo
> parsed as /and Foo
> Fix bug 687277 from customer 440
>
> This is a draft version.
> I'm not sure that we need another user parameter but the current
> usage of PDFScanRules is not compatible with catching syntax errors.
> Alternatively, we can set PDFScanRules before running the PDF file
> but this will prevent us from validating the PDF file.
>
> The change will be documented later if the fix is accepted in general.
>
> The fix was tested on a small set of files only.
>


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> Index: gs/src/iscan.h
> ===================================================================
> RCS file: /cvs/ghostscript/gs/src/iscan.h,v
> retrieving revision 1.8
> diff -b -u -r1.8 iscan.h
> --- gs/src/iscan.h 16 Jun 2002 04:47:10 -0000 1.8
> +++ gs/src/iscan.h 3 Feb 2004 06:05:38 -0000
> @@ -117,6 +117,9 @@
>  #define SCAN_PDF_RULES 16 /* Special PDF scanning rules used */
>   /* This is for compatibility with Adobe */
>   /* Acrobat Reader */
> +#define SCAN_NO_IMMEDIATE_EVAL 32 /* Disable immediate evaluation. Scan
//Name */
> +                                /* as / and /Name. This is set for PDF
and */
> +                                /* can be useful for Level 1
compatibility */
>  void scanner_state_init_options(scanner_state *sstate, int options);
>  #define scanner_state_init_check(pstate, from_string, check_only)\
>    scanner_state_init_options(pstate,\
> Index: gs/src/iscan.c
> ===================================================================
> RCS file: /cvs/ghostscript/gs/src/iscan.c,v
> retrieving revision 1.16
> diff -b -u -r1.16 iscan.c
> --- gs/src/iscan.c 4 Dec 2003 12:35:35 -0000 1.16
> +++ gs/src/iscan.c 3 Feb 2004 06:05:38 -0000
> @@ -434,6 +434,7 @@
>      int sign;
>      const bool check_only = (pstate->s_options & SCAN_CHECK_ONLY) != 0;
>      const bool PDFScanRules = (i_ctx_p->scanner_options & SCAN_PDF_RULES)
!= 0;
> +    const bool no_immediate_eval = (i_ctx_p->scanner_options &
SCAN_NO_IMMEDIATE_EVAL) != 0;
>      scanner_state sstate;
>
>  #define pstack sstate.s_pstack
> @@ -679,8 +680,16 @@
>       ensure2(scanning_none);
>       c = scan_getc();
>       if (c == '/') {
> +         if (no_immediate_eval) {
> +     name_type = 1;
> +                    try_number = false;
> +                    da.base = da.limit = daptr = 0;
> +     da.is_dynamic = false;
> +     goto nx;
> +                } else {
>   name_type = 2;
>   c = scan_getc();
> +         }
>       } else
>   name_type = 1;
>       try_number = false;
> Index: gs/src/ztoken.c
> ===================================================================
> RCS file: /cvs/ghostscript/gs/src/ztoken.c,v
> retrieving revision 1.12
> diff -b -u -r1.12 ztoken.c
> --- gs/src/ztoken.c 15 May 2003 22:25:47 -0000 1.12
> +++ gs/src/ztoken.c 3 Feb 2004 06:05:38 -0000
> @@ -343,10 +343,11 @@
>   const char *pname;
>   int option;
>      } named_scanner_option_t;
> -    static const named_scanner_option_t named_options[3] = {
> +    static const named_scanner_option_t named_options[4] = {
>   {"ProcessComment", SCAN_PROCESS_COMMENTS},
>   {"ProcessDSCComment", SCAN_PROCESS_DSC_COMMENTS},
> - {"PDFScanRules", SCAN_PDF_RULES}
> + {"PDFScanRules", SCAN_PDF_RULES},
> +        {"NoImmediateEval", SCAN_NO_IMMEDIATE_EVAL}
>      };
>      int options = old_options;
>      int i;
> Index: gs/lib/pdf_main.ps
> ===================================================================
> RCS file: /cvs/ghostscript/gs/lib/pdf_main.ps,v
> retrieving revision 1.84
> diff -b -u -r1.84 pdf_main.ps
> --- gs/lib/pdf_main.ps 19 Jan 2004 16:52:32 -0000 1.84
> +++ gs/lib/pdf_main.ps 3 Feb 2004 06:05:39 -0000
> @@ -117,6 +117,7 @@
>   % This is counter-intuitive, and we don't understand why it happens,
>   % but the improvement is significant.
>     /PDFTopSave save def
> +   << /NoImmediateEval true >> setuserparams
>     0 setobjectformat
>     /Page# null def
>     /Page null def
> Index: gs/lib/pdf_draw.ps
> ===================================================================
> RCS file: /cvs/ghostscript/gs/lib/pdf_draw.ps,v
> retrieving revision 1.79
> diff -b -u -r1.79 pdf_draw.ps
> --- gs/lib/pdf_draw.ps 22 Oct 2003 08:55:44 -0000 1.79
> +++ gs/lib/pdf_draw.ps 3 Feb 2004 06:05:39 -0000
> @@ -984,6 +984,7 @@
>    DOPS
>     {
>       //_dops_save 0 save put
> +     << /NoImmediateEval false >> setuserparams
>       true resolvestream cvx exec
>       //_dops_save 0 get restore
>     }
>


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