1061333 - Font sanitizer rejects Ozrad CLM with "CFF : failed to parse table"

Status: RESOLVED INVALID

(Core :: Graphics: Text, defect)

Description

[Simon Montagu :smontagu]

The font Ozrad CLM, from http://culmus.sourceforge.net/fancy/ozrad-otf.zip, works locally but fails as a downloaded font. The error messages in web console for the testcase http://smontagu.org/testcases/ozrad_test.html are:

downloadable font: CFF : failed to parse table (font-family: "Ozrad" style:normal weight:normal stretch:normal src index:0)
source: http://smontagu.org/testcases/OzradCLM-Bold.otf
downloadable font: rejected by sanitizer (font-family: "Ozrad" style:normal weight:normal stretch:normal src index:0)
source: http://smontagu.org/testcases/OzradCLM-Bold.otf

Comment 1

[Jonathan Kew [:jfkthame]]

OTS is correct, I think: the font has an invalid PrivateDict. Specifically, the /BlueValues key is lacking an operand. This shows up in a TTX dump as

    <CFFFont name="OzradCLM-Bold">
      ...snipped...
      <Private>
        <BlueValues value=""/>
        ...etc

whereas the Adobe CFF spec says that /BlueValues expects a <delta> operand.

Probably a bug in the tool originally used to generate the font.

Comment 2

[John Daggett (:jtd)]

In general, OTS errors mean something is amiss with the font data. Platform font libraries permit all sorts of malformed font data but OTS does not. It would be nice if we could be less stringent about what passes through OTS but for safety sake we can't. So "font works but OTS rejects" isn't really a valid bug in general.

Although it may not help much, enabling OTS_DEBUG at the top of gfx/ots/src/ots.h will spit out the details of exactly what OTS doesn't like.