2 files changed, 10 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 62d5ae1778..911dea4e74 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Dec 15 14:32:18 2004  NAKAMURA Usaku  <[email protected]>
+
+	* win32/win32.c (rb_w32_fdisset): check whether the handle is valid.
+
 Tue Dec 14 19:17:15 2004  Yukihiro Matsumoto  <[email protected]>
 
 	* utf8.c (utf8_is_mbc_ambiguous): [ruby-talk:123561]
diff --git a/win32/win32.c b/win32/win32.c
index 7a7078335f..c21fca6fbc 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -1827,7 +1827,12 @@ rb_w32_fdclr(int fd, fd_set *set)
 int
 rb_w32_fdisset(int fd, fd_set *set)
 {
-       return __WSAFDIsSet(TO_SOCKET(fd), set);
+    int ret;
+    SOCKET s = TO_SOCKET(fd);
+    if (s == (SOCKET)INVALID_HANDLE_VALUE)
+        return 0;
+    RUBY_CRITICAL(ret = __WSAFDIsSet(s, set));
+    return ret;
 }
 
 //