--- a/Context.st	Thu Jun 04 13:17:16 1998 +0200
+++ b/Context.st	Thu Jun 04 17:18:52 1998 +0200
@@ -112,6 +112,9 @@
 					    locals and temporaries.
 
 	sender      <Context>               the 'calling / sending' context
+					    This is not directly accessable, since it may
+					    be a lazy context (i.e. an empty frame).
+					    The #sender method cares for this.
 
 	home        <Context>               the context, where this block was 
 					    created, or nil if its a method context
@@ -275,6 +278,7 @@
      Notice, that one of the next ST/X versions will get some syntactic
      extension to get this automatically)."
 
+    (index == 2) ifTrue:[^ self sender]."/ sender - must be accessed specially
     (index == 8) ifTrue:[^ nil].	"/ retvalTemp - invisible
     (index == 9) ifTrue:[^ nil].	"/ handle to machine stack - invisible
     ^ super instVarAt:index
@@ -305,7 +309,7 @@
      To save time during normal execution, this information is not held in the
      context, but computed here on request."
 
-    |c sender sendersSelector|
+    |c sender sendersSelector m|
 
     c := self searchClass.
     "
@@ -324,7 +328,7 @@
 	^ c compiledMethodAt:selector
     ].
 
-    "mhmh - seems to be a context for an unbound method;
+    "mhmh - seems to be a context for an unbound method (as generated by doIt);
      look in the senders context. Consider this a kludge.
      (maybe it was not too good of an idea to NOT keep the current
       method in the context ...)
@@ -336,7 +340,10 @@
 	sendersSelector := sender selector.
 	sendersSelector notNil ifTrue:[
 	    (sendersSelector startsWith:'valueWithReceiver:') ifTrue:[
-		^ sender receiver
+		m := sender receiver.
+		m isMethod ifTrue:[
+		    ^ m
+		]
 	    ]
 	]
     ].
@@ -448,11 +455,11 @@
 %{  /* NOCONTEXT */
     OBJ theContext;
 
+    theContext = __INST(sender_);
     /*
      * this special nil test is for the very first context (startup-context);
      * actually, its cosmetics, to avoid a visible nil>>nil context in the debugger.
      */
-    theContext = __INST(sender_);
     if (__isNonNilObject(theContext)) {
 
 	if (__isLazy(theContext)) {
@@ -461,14 +468,16 @@
 	     */
 	    __PATCHUPCONTEXT(theContext);
 	}
-	/* 
-	 * to be prepared for the worst situation 
-	 * (the sender is not stored, so the trap wont catch it)
-	 * make the writeBarrier trigger manually.
-	 * We'll see, if this is really required.
-	 */
-	theContext->o_space |= CATCHMARK;
-	_markNonLIFO(theContext);
+	if (! __isNonLIFO(theContext)) {
+	    /* 
+	     * to be prepared for the worst situation 
+	     * (the sender is not stored, so the trap wont catch it)
+	     * make the writeBarrier trigger manually.
+	     * We'll see, if this is really required.
+	     */
+	    theContext->o_space |= CATCHMARK;
+	    _markNonLIFO(theContext);
+	}
     }
     RETURN (theContext);
 %}
@@ -887,7 +896,7 @@
 	   && (__ContextInstPtr(theContext)->c_sender != self)) {
 	theContext = __ContextInstPtr(theContext)->c_sender;
     }
-    if (theContext) {
+    if (theContext != nil) {
 	if (__isLazy(theContext)) {
 	    __PATCHUPCONTEXT(theContext);
 	}
@@ -1325,8 +1334,7 @@
      - a highly internal mechanism and not for public use."
 
 %{  /* NOCONTEXT */
-     __INST(flags) = (OBJ)((INT)__INST(flags) 
-		     | __MASKSMALLINT(__IRQ_ON_UNWIND));
+     __INST(flags) = (OBJ)((INT)__INST(flags) | __MASKSMALLINT(__IRQ_ON_UNWIND));
 %}
 !
 
@@ -1368,7 +1376,7 @@
 
 %{  /* NOCONTEXT */
 
-    RETURN ( (__intVal(__INST(flags)) & __CANNOT_RETURN) ? false : true );
+    RETURN ( ((INT)(__INST(flags)) & __MASKSMALLINT(__CANNOT_RETURN)) ? false : true );
 %}
 !
 
@@ -1483,6 +1491,6 @@
 !Context class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/Context.st,v 1.86 1998-03-31 13:52:54 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/Context.st,v 1.87 1998-06-04 15:18:52 cg Exp $'
 ! !
 Context initialize!