--- a/macro.c	Fri Jun 12 02:21:28 2015 -0400
+++ b/macro.c	Fri Jun 12 02:38:04 2015 -0400
@@ -1246,11 +1246,22 @@
 	doexpand(&mainstate, p, buf, len);
 	switch (mainstate.state) {
 	    case ES_NORMAL:
-		output(p, "\n", 1);
+		/*
+		 * If we were sent a blank line, don't emit a newline
+		 * for it. This matches the prior behavior of tradcpp.
+		 */
+		if (len > 0) {
+			output(p, "\n", 1);
+		}
 		break;
 	    case ES_WANTLPAREN:
 	    case ES_NOARG:
 	    case ES_HAVEARG:
+		/*
+		 * Apparently to match gcc's -traditional behavior we
+		 * need to emit a space for each newline that appears
+		 * while processing macro args.
+		 */
 		expand_got_ws(&mainstate, p, " ", 1);
 		break;
 	}