*** win32.c~	Sun Oct 03 19:07:01 2010
--- win32.c	Sun Oct 10 01:02:17 2010
*************** static struct {
*** 212,217 ****
--- 212,229 ----
  int
  rb_w32_map_errno(DWORD winerr)
  {
+     return rb_w32_exchange_errno(winerr, 0);
+ }
+ 
+ int
+ rb_w32_unmap_errno(DWORD err)
+ {
+     return rb_w32_exchange_errno(err, 1);
+ }
+ 
+ static int
+ rb_w32_exchange_errno(DWORD winerr, int direction)
+ {
      int i;
  
      if (winerr == 0) {
*************** rb_w32_map_errno(DWORD winerr)
*** 219,226 ****
      }
  
      for (i = 0; i < (int)(sizeof(errmap) / sizeof(*errmap)); i++) {
! 	if (errmap[i].winerr == winerr) {
! 	    return errmap[i].err;
  	}
      }
  
--- 231,244 ----
      }
  
      for (i = 0; i < (int)(sizeof(errmap) / sizeof(*errmap)); i++) {
!         if (direction) {
!             if (errmap[i].err == winerr) {
!                 return errmap[i].winerr;
!             }
!         } else {
!             if (errmap[i].winerr == winerr) {
!                 return errmap[i].err;
!             }
  	}
      }
  
*************** rb_w32_map_errno(DWORD winerr)
*** 231,236 ****
--- 249,255 ----
  }
  
  #define map_errno rb_w32_map_errno
+ #define unmap_errno rb_w32_unmap_errno
  
  static const char *NTLoginName;
  
*************** rb_w32_strerror(int e)
*** 2198,2211 ****
      if (e < 0 || e > sys_nerr) {
  	if (e < 0)
  	    e = GetLastError();
  	if (FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
  			  FORMAT_MESSAGE_IGNORE_INSERTS, &source, e, 0,
  			  buffer, sizeof(buffer), NULL) == 0)
  	    strlcpy(buffer, "Unknown Error", sizeof(buffer));
      }
!     else
  	strlcpy(buffer, strerror(e), sizeof(buffer));
! 
      p = buffer;
      while ((p = strpbrk(p, "\r\n")) != NULL) {
  	memmove(p, p + 1, strlen(p));
--- 2217,2233 ----
      if (e < 0 || e > sys_nerr) {
  	if (e < 0)
  	    e = GetLastError();
+         else
+             e = unmap_errno(e);
  	if (FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM |
  			  FORMAT_MESSAGE_IGNORE_INSERTS, &source, e, 0,
  			  buffer, sizeof(buffer), NULL) == 0)
  	    strlcpy(buffer, "Unknown Error", sizeof(buffer));
      }
!     else {
  	strlcpy(buffer, strerror(e), sizeof(buffer));
!     }
!     
      p = buffer;
      while ((p = strpbrk(p, "\r\n")) != NULL) {
  	memmove(p, p + 1, strlen(p));