- ( ((unsigned char)(c)!=(f)->lbf && (f)->wpos!=(f)->wend) \
- ? *(f)->wpos++ = (c) : __overflow((f),(c)) )
+ ( (((unsigned char)(c)!=(f)->lbf && (f)->wpos!=(f)->wend)) \
+ ? *(f)->wpos++ = (unsigned char)(c) \
+ : __overflow((f),(unsigned char)(c)) )