GOB: Don't crash if getCharData() returns NULL

This happened to me when playing the floppy version of Gobliins 2. I
don't know if it's a fix or a workaround, but the function can clearly
return NULL so let's guard against it.

svn-id: r52813

1 files changed, 10 insertions, 0 deletions

diff --git a/engines/gob/driver_vga.cpp b/engines/gob/driver_vga.cpp
index c93962c206..7be1daf9f3 100644
--- a/engines/gob/driver_vga.cpp
+++ b/engines/gob/driver_vga.cpp
@@ -75,6 +75,16 @@ void VGAVideoDriver::drawLetter(unsigned char item, int16 x, int16 y,
 	uint16 data;
 
 	const byte *src = font.getCharData(item);
+
+	// This happens for me at the mountain (World 6) in Gobliins 2, if I
+	// move the cursor over the "!" part of the ledge while trying to use
+	// an object.
+
+	if (!src) {
+		warning("drawLetter: getCharData() returned NULL");
+		return;
+	}
+
 	byte *dst = dest.getVidMem() + x + dest.getWidth() * y;
 
 	int nWidth = font.getCharWidth();