Re: [Devel] infinite loop/autohinter crash

[Scott Long]

I have located the problem. Our translation process is not at fault -- we 
extract TTF data from a PCL stream and convert it to a TTF file image. It 
turns out the PCL data stream itself has some problems.

Blame Windows :-)

Here's the patch I just came up with as a temporary fix. It just makes 
FreeType a little more defensive. I'm sure you guys can come up with a better 
way to handle this sort of error, but for the moment, this patch works for me:

--- ttgload.c   Sat Jul  7 09:12:14 2001
+++ ttgload.c   Thu Dec 13 16:57:52 2001
@@ -723,6 +723,13 @@
     if ( index < (FT_UInt)face->num_locations - 1 )
        count = face->glyph_locations[index + 1] - offset;

+    if ( count < 10 )
+    {
+      /* This glyph is corrupted -- it does not have a complete header */
+      error = TT_Err_Invalid_Outline;
+      goto Fail;
+    }
+
     if ( count == 0 )
     {
       /* as described by Frederic Loyer, these are spaces, and */


(end of patch)

On Thursday 13 December 2001 04:57 pm, you wrote:
> Werner LEMBERG wrote:
> > The remaining tables are completely useless.  It seems that your
> > translation process is severely broken.
> >
> > Just, any chance to make ttDump continue?  Since FreeType 1 can
> > display the font (albeit incompletely), the errors aren't apparently
> > too severe.
>
> I second Werner here: it would be great to have a way to somewhat pass
> over "benign" fault/exception. But I understand this is nowhere near
> from easy...
>
> Back to the topic, though, Scott did a valid point that you (Werner)
> is relaying to Just: we should not allow the engine to stop badly
> on such a problem; and Scott's point is that it concerns Freetype...
>
>
>
> Antoine
>
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