diff -rc db-4.4.20.NC-old/os/os_flock.c db-4.4.20.NC/os/os_flock.c
*** db-4.4.20.NC-old/os/os_flock.c	Mon Jun 20 16:59:01 2005
--- db-4.4.20.NC/os/os_flock.c	Wed Jun  7 17:01:49 2006
***************
*** 36,41 ****
--- 36,50 ----
  
  	DB_ASSERT(F_ISSET(fhp, DB_FH_OPENED) && fhp->fd != -1);
  
+ #ifdef __CYGWIN__
+ 	/*
+ 	 * Windows file locking interferes with read/write operations, so we
+ 	 * map the ranges to an area past the end of the file.
+ 	 */
+ 	DB_ASSERT(offset < (off_t) 1 << 62);
+ 	offset += (off_t) 1 << 62;
+ #endif
+ 
  #ifdef HAVE_FCNTL
  	fl.l_start = offset;
  	fl.l_len = 1;
