GCC-4 fix:

mng.c: In function 'copyline':
mng.c:233: error: invalid lvalue in increment
mng.c:270: error: invalid lvalue in increment

--- libmng-1.0.10/contrib/gcc/fbmngplay/mng.c.orig	2003-12-07 10:45:15.000000000 +0100
+++ libmng-1.0.10/contrib/gcc/fbmngplay/mng.c	2007-07-16 19:47:18.272161096 +0200
@@ -230,7 +230,8 @@
 		a = a * mymng->alpha / 100;
 		switch (mymng->fbbpp) {
 		case 16:
-			input = *((unsigned short *) background)++;
+			input = *(unsigned short *)background;
+			background += 2;
 			br = (input >> 8) & 0xf8;
 			bg = (input >> 3) & 0xfc;
 			bb = input << 3 & 0xff;
@@ -267,7 +268,8 @@
 			b >>= 3;
 
 			output = (r << 11) | (g << 5) | b;
-			*((unsigned short *) dest)++ = output;
+			*(unsigned short *)dest = output;
+			dest += 2;
 			break;
 		case 24:
 			*dest++ = b;