--- contrib/xwintoppm/dsimple.c

+++ contrib/xwintoppm/dsimple.c

@@ -503,6 +503,7 @@

 	fprintf(stderr, msg, arg0, arg1, arg2, arg3, arg4, arg5, arg6);

 	fprintf(stderr, "\n");

 	fflush(stderr);

+	return 0;

 }

--- contrib/xwintoppm/xwintoppm.c

+++ contrib/xwintoppm/xwintoppm.c

@@ -604,6 +604,7 @@

      * Free image

      */

     XDestroyImage(image);

+    return 0;

 }

 /*

@@ -729,6 +730,7 @@

 	bp++;

 	*bp++ = c;

     }

+    return 0;

 }

 _swaplong (bp, n)

@@ -750,4 +752,5 @@

 	*bp++ = c;

 	bp += 2;

     }

+    return 0;

 }