(svn r25511) -Fix-ish: add the same printable key assert to the sprite font cache as the freetype font cache

src/fontcache.cpp

@@ -76,7 +76,7 @@ public:
 	virtual const Sprite *GetGlyph(GlyphID key);
 	virtual uint GetGlyphWidth(GlyphID key);
 	virtual bool GetDrawGlyphShadow();
-	virtual GlyphID MapCharToGlyph(WChar key) { return SPRITE_GLYPH | key; }
+	virtual GlyphID MapCharToGlyph(WChar key) { assert(IsPrintable(key)); return SPRITE_GLYPH | key; }
 	virtual const void *GetFontTable(uint32 tag, size_t &length) { length = 0; return NULL; }
 };