diff mbox

vdr 1.5.16 - minor problem in font.c

Message ID 47C80A6F.3080406@cadsoft.de
State New
Headers

Commit Message

Klaus Schmidinger Feb. 29, 2008, 1:36 p.m. UTC 
  On 02/29/08 14:29, Klaus Schmidinger wrote:
> On 02/29/08 01:04, Tobi wrote:
>> Hello,
>>
>> DrawText() in font.c uses the method Glyph() which may return a null pointer,
>> but doesn't check the returned pointer.
>>
>> I came across this bug, when checking a bug report from Sven Mueller:
>>
>> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=467512
>>
>> When info.vdr contains an invalid character (like in the above example a 0xA0 -
>> a Latin-1 NO-BREAK SPACE),  Glyph() returns null, which then causes a segfault
>> when dereferencing the null-pointer.
>>
>> The easiest way to fix this, would probably be to ignore such invalid
>> characters, which is, what the attached two-line-patch will do. But maybe it's
>> better to replace such characters with a default character - maybe a space or a '?'.
> 
> I also think showing some replacement character is best.
> 
> Can you please verify if the attached patch does this correctly?
> 
> If this works, I'd like to include it in version 1.6.0.

Maybe the attached version is even better, because there are also other
places where Glyph() is called.

Klaus
diff mbox

Patch

--- font.c	2008/02/09 11:52:25	1.23
+++ font.c	2008/02/29 13:35:15
@@ -214,6 +214,9 @@ 
         return Glyph;
         }
      }
+#define UNKNOWN_GLYPH_INDICATOR '?'
+  if (CharCode != UNKNOWN_GLYPH_INDICATOR)
+     return Glyph(UNKNOWN_GLYPH_INDICATOR);
   return NULL;
 }
 
@@ -258,6 +261,8 @@ 
            uint sym = Utf8CharGet(s, sl);
            s += sl;
            cGlyph *g = Glyph(sym, AntiAliased);
+           if (!g)
+              continue;
            int kerning = Kerning(g, prevSym);
            prevSym = sym;
            uchar *buffer = g->Bitmap();