diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b9eeac7cf938..9d7135052065 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2001-05-22  Alexandre Oliva  <aoliva@redhat.com>
+
+	* cppfiles.c (remove_component_p): Don't assume lstat/stat will
+	keep errno unchanged on success.
+
 2001-05-22  Joseph S. Myers  <jsm28@cam.ac.uk>
 
 	* c-lex.c (lex_number): If pedantic and not C99, pedwarn exactly
diff --git a/gcc/cppfiles.c b/gcc/cppfiles.c
index dea6dd6677e1..137882b340c2 100644
--- a/gcc/cppfiles.c
+++ b/gcc/cppfiles.c
@@ -1027,6 +1027,12 @@ remove_component_p (path)
   result = stat (path, &s);
 #endif
 
+  /* There's no guarantee that errno will be unchanged, even on
+     success.  Cygwin's lstat(), for example, will often set errno to
+     ENOSYS.  In case of success, reset errno to zero.  */
+  if (result == 0)
+    errno = 0;
+
   return result == 0 && S_ISDIR (s.st_mode);
 }