--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/cpp/avoidpaste2.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,31 @@
+/* Copyright (C) 2001, 2003 Free Software Foundation, Inc.  */
+
+/* { dg-do preprocess } */
+/* { dg-options "-ansi" } */
+
+/* This tests that we avoid accidental pasting, as well as gratuitous
+   space insertion, in various nasty places _inside_ a macro's
+   replacement list: on either side of a paste, and on either side of
+   an argument.  It also tests that we don't pass empty macro leading
+   whitespace to the next line - this problem use to break Emacs
+   preprocessor abuse.
+
+   Neil Booth, 1 Feb 2001.  */
+
+#define EMPTY_WITH_LEADING_SPACE
+#define f(x, y) :x: -y##> -##y>
+#define g(x, y) :x: :y##2 2##y:
+
+/* This should preprocess as
+
+: : : - > - >
+:2: :22 22:
+
+We used to get a space at the start of the line.  */
+
+ EMPTY_WITH_LEADING_SPACE
+f(:,) 
+g(2, 2)
+
+/* { dg-final { scan-file avoidpaste2.i "(^|\\n): : : - > - >" } } 
+   { dg-final { scan-file avoidpaste2.i "(^|\\n):2: :22 22:" } } */