diff --git a/docs/nmap.usage.txt b/docs/nmap.usage.txt
index cc3e0ca69..548a0c6ae 100644
--- a/docs/nmap.usage.txt
+++ b/docs/nmap.usage.txt
@@ -1,4 +1,4 @@
-Nmap 4.20ALPHA11 ( http://insecure.org )
+Nmap 4.20RC1 ( http://insecure.org )
 Usage: nmap [Scan Type(s)] [Options] {target specification}
 TARGET SPECIFICATION:
   Can pass hostnames, IP addresses, networks, etc.
diff --git a/libpcre/pcre_winconfig.h b/libpcre/pcre_winconfig.h
index ff6fcee29..e3fa1ac2f 100644
--- a/libpcre/pcre_winconfig.h
+++ b/libpcre/pcre_winconfig.h
@@ -33,6 +33,35 @@ default default. */
 #define MATCH_LIMIT 10000000
 #endif
 
+/* The above limit applies to all calls of match(), whether or not they
+increase the recursion depth. In some environments it is desirable to limit the
+depth of recursive calls of match() more strictly, in order to restrict the
+maximum amount of stack (or heap, if NO_RECURSE is defined) that is used. The
+value of MATCH_LIMIT_RECURSION applies only to recursive calls of match(). To
+have any useful effect, it must be less than the value of MATCH_LIMIT. There is
+a runtime method for setting a different limit. On systems that support it,
+"configure" can be used to override this default default. */
+
+#ifndef MATCH_LIMIT_RECURSION
+#define MATCH_LIMIT_RECURSION MATCH_LIMIT
+#endif
+
+/* These three limits are parameterized just in case anybody ever wants to
+change them. Care must be taken if they are increased, because they guard
+against integer overflow caused by enormously large patterns. */
+
+#ifndef MAX_NAME_SIZE
+#define MAX_NAME_SIZE 32
+#endif
+
+#ifndef MAX_NAME_COUNT
+#define MAX_NAME_COUNT 10000
+#endif
+
+#ifndef MAX_DUPLENGTH
+#define MAX_DUPLENGTH 30000
+#endif
+
 // This is set by configure on other platforms -Fyodor
 #define POSIX_MALLOC_THRESHOLD 10
 
diff --git a/tcpip.cc b/tcpip.cc
index dbb559e36..d78b1d06a 100644
--- a/tcpip.cc
+++ b/tcpip.cc
@@ -1846,7 +1846,7 @@ if (!pd) fatal("NULL packet device passed to readip_pcap");
 
  pcap_descriptor = -1;
  if (pcap_selectable_fd_valid())  
-   pcap_descriptor = pcap_get_selectable_fd(pd);
+   pcap_descriptor = my_pcap_get_selectable_fd(pd);
 
  do {
 #ifdef WIN32
@@ -1956,6 +1956,20 @@ bool pcap_selectable_fd_valid() {
   return true;
 }
 
+/* Call this instead of pcap_get_selectable_fd directly (or your code
+   won't compile on Windows).  On systems which don't seem to support
+   the pcap_get_selectable_fd() function properly, returns -1,
+   otherwise simply calls pcap_selectable_fd and returns the
+   results.  If you just want to test whether the function is supported,
+   use pcap_selectable_fd_valid() instead. */
+int my_pcap_get_selectable_fd(pcap_t *p) {
+#if defined(WIN32) || defined(MACOSX)
+  return -1;
+#else
+  assert(pcap_selectable_fd_valid());
+  return pcap_get_selectable_fd(p);
+#endif
+}
 
  
 // Returns whether the packet receive time value obtained from libpcap
@@ -2078,7 +2092,7 @@ int read_arp_reply_pcap(pcap_t *pd, u8 *sendermac, struct in_addr *senderIP,
 
    pcap_descriptor = -1;
    if (pcap_selectable_fd_valid())  
-     pcap_descriptor = pcap_get_selectable_fd(pd);
+     pcap_descriptor = my_pcap_get_selectable_fd(pd);
     
    p = NULL;
    if (pcap_descriptor != -1) {
diff --git a/tcpip.h b/tcpip.h
index f5b9aaf20..5624e7b22 100644
--- a/tcpip.h
+++ b/tcpip.h
@@ -621,6 +621,13 @@ pcap_t *my_pcap_open_live(const char *device, int snaplen, int promisc,
 // Returns whether the system supports pcap_get_selectable_fd() properly
 bool pcap_selectable_fd_valid();
 
+/* Call this instead of pcap_get_selectable_fd directly (or your code
+   won't compile on Windows).  On systems which don't seem to support
+   the pcap_get_selectable_fd() function properly, returns -1,
+   otherwise simply calls pcap_selectable_fd and returns the
+   results.  If you just want to test whether the function is supported,
+   use pcap_selectable_fd_valid() instead. */
+int my_pcap_get_selectable_fd(pcap_t *p);
 
 // Returns whether the packet receive time value obtaned from libpcap
 // (and thus by readip_pcap()) should be considered valid.  When