winedos / Pass original code and stack pointers to PM DOS relays

[Jukka Heinonen <jhei@iki.fi>]

This is the first part of FPU emulation fix.
This patch should also make it possible to
simplify raw mode switch code.




Changelog:
  When forcing call to DOS relay from protected mode,
  make sure that relay sees original stack and code
  pointers. Make it possible for DOS relay to modify
  code and stack pointers.




Index: dlls/winedos/relay.c
===================================================================
RCS file: /home/wine/wine/dlls/winedos/relay.c,v
retrieving revision 1.2
diff -u -r1.2 relay.c
--- dlls/winedos/relay.c	23 Jun 2003 03:35:51 -0000	1.2
+++ dlls/winedos/relay.c	18 Aug 2003 18:55:13 -0000
@@ -103,12 +103,37 @@
  * This stub is called by __wine_call_from_16_regs in order to marshall
  * relay parameters.
  */
-static void __stdcall RELAY_RelayStub( DOSRELAY proc, 
+static void __stdcall RELAY_RelayStub( DOSRELAY       proc, 
                                        unsigned char *args, 
-                                       void *context )
+                                       void          *ctx86 )
 {
     if (proc)
-        proc( (CONTEXT86*)context, *(LPVOID *)args );
+    {
+        CONTEXT86     *context    = (CONTEXT86*)ctx86;
+        RELAY_Stack16 *stack      = RELAY_GetPointer( context->Esp );
+
+        DWORD          old_seg_cs = context->SegCs;
+        DWORD          old_eip    = context->Eip;
+        DWORD          old_seg_ss = context->SegSs;
+        DWORD          old_esp    = context->Esp;
+
+        context->SegCs = stack->seg_cs;
+        context->Eip   = stack->eip;
+        context->SegSs = stack->seg_ss;
+        context->Esp   = stack->esp;
+
+        proc( context, *(LPVOID *)args );
+
+        stack->seg_cs = context->SegCs;
+        stack->eip    = context->Eip;
+        stack->seg_ss = context->SegSs;
+        stack->esp    = context->Esp;
+
+        context->SegCs = old_seg_cs;
+        context->Eip   = old_eip;
+        context->SegSs = old_seg_ss;
+        context->Esp   = old_esp;
+    }
 }
 



-- 
Jukka Heinonen <http://www.iki.fi/jhei/>