[NTG-pdftex] [ pdftex-Patches-864 ] \suppressfontnotfounderror patch

[noreply at sarovar.org]

Patches item #864, was opened at 2007-09-17 17:49
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Category: Primitives
Group: v1.50.0
>Status: Closed
Resolution: Accepted
Priority: 5
Submitted By: Taco Hoekwater (taco)
Assigned to: Martin Schröder (oneiros)
Summary: \suppressfontnotfounderror patch

Initial Comment:
Attached is a patch for pdftex 1.50 (current trunk)
that introduces
a new integer parameter named \suppressfontnotfounderror.

If this parameter is non-zero, then (pdf)tex will not
complain about
font metric files that are not found, but silently skip
the font
assignment, making the requested csname \ifx-equal to
\nullfont.

The purpose is to allow macro programmers a way to
gracefully
recover from a missing or differently named font.

I am aware there is a trick that uses \batchmode to
test for font
existance, but the downside of that is that it calls
TeX's error()
routine, which clobbers the executable's return value.
That makes
it a no-no in "make"-like environments where the return
value of
TeX is checked to decide on further actions.

This functionality will also be added to the next
versions of xetex
and luatex (that's why the name does not start with
\pdf...).

 % simple example usage
 \def\testfont#1{%
   \font\junk=#1
   \ifx\junk\nullfont  \message{Font #1 not found}
   \else               \message{Font #1 found}
   \fi }

 {\suppressfontnotfounderror=1   \testfont{cmr-junk} }
 \bye


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Comment By: Martin Schröder (oneiros)
Date: 2007-12-18 15:25

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This patch will be included in the upcoming 1.50

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Comment By: Taco Hoekwater (taco)
Date: 2007-09-18 08:10

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Well, at least it does not affect the tex user directly:
there is a stream of garbage on the screen and that looks
ugly, but there is no error interaction, and the
system-level return value of pdftex is unaffected.

I don't know if there is a clean way to control mktextfm cs,
but if it can be done, that would be a nice addition to the
web2c change file.

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Comment By: Martin Schröder (oneiros)
Date: 2007-09-17 21:53

Message:
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IMHO it works only somuch, but that may be due to kpathsea:
> pdftex test.tex 
This is pdfTeX, Version 3.141592-1.50.0-alpha-20070917
(Web2C 7.5.6)
entering extended mode
(./test.texkpathsea: Running mktextfm cmr-junk
mktextfm: Running mf-nowin -progname=mf \mode:=lexmarkr;
mag:=1; nonstopmode; input cmr-junk
This is METAFONT, Version 2.71828 (Web2C 7.5.4)

kpathsea: Running mktexmf cmr-junk
! I can't find file `cmr-junk'.
<*> ...xmarkr; mag:=1; nonstopmode; input cmr-junk
                                                  
Please type another input file name
! Emergency stop.
<*> ...xmarkr; mag:=1; nonstopmode; input cmr-junk
                                                  
Transcript written on mfput.log.
grep: cmr-junk.log: Datei oder Verzeichnis nicht gefunden
mktextfm: `mf-nowin -progname=mf \mode:=lexmarkr; mag:=1;
nonstopmode; input cmr-junk' failed to make cmr-junk.tfm.
kpathsea: Appending font creation commands to missfont.log.
 Font cmr-junk not found )
No pages of output.
Transcript written on test.log.

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