On Wed, Mar 06, 2013 at 07:35:26AM +1100, Kevin Ryde wrote:
> gdb claims it to be in wxPostScriptDC::DoGetTextExtent() dcpsg.cpp line
> 2151 and has p==NULL.  If my sources are up-to-date that line would be
> 
>     for(p=(unsigned char *)wxMBSTRINGCAST strbuf; *p; p++)
> 
> Maybe it's something locale related.  If I make a utf8 and switch to it
> like LC_ALL=en_US.UTF-8 then the print works.  In that case it warns too
> that I don't have file /usr/share/wx/gs_afm/Helv.afm, if that makes a
> difference.
> 
> Is that p strbuf thing a conversion to a locale string to measure the
> characters or something?  Dunno what it should do if the locale is not
> enough for the string to be printed, but you'd hope it didn't crash.

I forwarded the bug upstream, who suggested just returning in this case,
and I came up with the attached patch which implements that.

My unstable chroot seems to have got in an odd state, so I haven't tried
building it yet, but if you have the setup to hand to reproduce the issue,
please give it a go and let me know if it fixes it.

Cheers,
    Olly
diff --git a/src/generic/dcpsg.cpp b/src/generic/dcpsg.cpp
index e2eadde..ce32934 100644
--- a/src/generic/dcpsg.cpp
+++ b/src/generic/dcpsg.cpp
@@ -2147,8 +2147,20 @@ void wxPostScriptDC::DoGetTextExtent(const wxString& string,
 
     long sum=0;
     float height=fontSize; /* by default */
-    unsigned char *p;
-    for(p=(unsigned char *)wxMBSTRINGCAST strbuf; *p; p++)
+    unsigned char *p=(unsigned char *)wxMBSTRINGCAST strbuf;
+    if(!p)
+    {
+        // String couldn't be converted which used to SEGV as reported here:
+        // http://bugs.debian.org/702378
+        // http://trac.wxwidgets.org/ticket/15300
+        // Upstream suggests "just return if the conversion failed".
+        if (x) (*x) = 0;
+        if (y) (*y) = 0;
+        if (descent) (*descent) = 0;
+        if (externalLeading) (*externalLeading) = 0;
+        return;
+    }
+    for(; *p; p++)
     {
         if(lastWidths[*p]== INT_MIN)
         {

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