Bug 79527

Summary:	Some characters from non-embedded symbol font are not displayed at all
Product:	poppler	Reporter:	Ulrich Lukas <stellplatz-nr.13a>
Component:	cairo backend	Assignee:	poppler-bugs <poppler-bugs>
Status:	RESOLVED NOTOURBUG	QA Contact:
Severity:	normal
Priority:	medium
Version:	unspecified
Hardware:	All
OS:	Linux (All)
Whiteboard:
i915 platform:		i915 features:
Attachments:	Screenshot from Okular, Mu-Character missing Screenshot Acroread, Mu-Character displayed OK Command line output when invoking ghostscript command

Description Ulrich Lukas 2014-06-02 05:50:41 UTC

Created attachment 100267 [details]
Screenshot from Okular, Mu-Character missing

Hi,

see e.g. followign PDF:
http://www.ti.com/lit/ds/symlink/tlv3201.pdf

On the middle right of the first page, the description field in the first line of the "related products" table contains the greek letter Mu ("µ").

When the PDF is displayed with e.g. Evince, Okular or XPDF (all using libpoppler 0.24.5), the Mu-character is displayed as white space. It can be copy+pasted correctly, though.

When the PDF is displayed with e.g. the PDF viewer embedded in Firefox or Adobe Reader, the Mu-character is rendered correctly.


==> Why do I /not/ suspect my installed fonts or fontconfig configuration as the culprits?

I can "repair" the PDF by embedding one of my installed system fonts using the following command:

/usr/bin/gs \
  -o gs-repaired-tlv3201.pdf \
  -dPDFSETTINGS=/prepress \
  -sDEVICE=pdfwrite \
   tlv3201.pdf

This apparently embeds the font "StandardSymbolsL" for the "Symbol" font used by the PDF.

Then, the same PDF with the system font embedded is displayed correctly by all poppler-based PDF-readers.


However, the original PDF without the embedded font is not rendered correctly even when configuring fontconfig in such a way that is explicityl uses "StandardSymbolsL" as a substitute for the "Symbol" font using a fonts.conf containing:

<match target="pattern">
 <test name="family">
  <string>Symbol</string>
 </test>
 <edit name="family" mode="prepend" binding="same">
  <string>StandardSymbolsL</string>
 </edit>
</match>


I am attaching a screenshot displaying the questionable section of the first page of the PDF, as incorrectly rendered by poppler and a second screenshot as rendered by Adobe Reader. Also, the commandline output of Ghostscript when embedding the system fonts.

Comment 1 Ulrich Lukas 2014-06-02 05:51:26 UTC

Created attachment 100268 [details]
Screenshot Acroread, Mu-Character displayed OK

Comment 2 Ulrich Lukas 2014-06-02 05:53:09 UTC

Created attachment 100269 [details]
Command line output when invoking ghostscript command

Comment 3 Albert Astals Cid 2014-06-03 23:04:39 UTC

Why set the component to cairo?

Comment 4 Ulrich Lukas 2014-06-03 23:51:00 UTC

(In reply to comment #3)
> Why set the component to cairo?

I set it to cairo because of bug #36536 which has a similar description.

This might have been a mistake.

Comment 5 Ulrich Lukas 2014-06-04 00:18:09 UTC

OK, I might have to retract this bug report.

I only tested an altered fontconfig-config for the "Symbol" font not embedded in the PDF, but I tested again today with extracted page 1 from the referenced PDF, which only has "Helvetica" and "Helvetica Bold" not embedded.

The default substitution for this font on my system seems to be "TeX Gyre Heros".

After just now adding the following to fonts.conf:

<match target="pattern">
 <test name="family">
  <string>Helvetica</string>
 </test>
 <edit name="family" mode="prepend" binding="same">
  <string>NimbusSansL</string>
 </edit>
</match>

The PDF is rendered OK..

Please excuse the false allegations of poppler..

This bug report can be closed.

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