winedos: Clear TF bit before passing control to a VM86 interrupt handler.

dlls/winedos/dosexe.h

@@ -98,6 +98,7 @@ extern struct DPMI_segments *DOSVM_dpmi_segments;
  * IF_MASK is only pushed into real mode stack.
  */
 #define V86_FLAG 0x00020000
+#define TF_MASK  0x00000100
 #define IF_MASK  0x00000200
 #define VIF_MASK 0x00080000
 #define VIP_MASK 0x00100000

dlls/winedos/interrupts.c

@@ -514,8 +514,8 @@ void DOSVM_HardwareInterruptRM( CONTEXT86 *context, BYTE intnum )
          context->SegCs = SELECTOROF( handler );
          context->Eip   = OFFSETOF( handler );
 
-         /* Clear virtual interrupt flag. */
-         context->EFlags &= ~VIF_MASK;
+         /* Clear virtual interrupt flag and trap flag. */
+         context->EFlags &= ~(VIF_MASK | TF_MASK);
      }
 }