revert pull/45, resume continuation should *NOT* discard handler's stack

src/runtime.c

@@ -403,10 +403,6 @@ continuationAsClosure(struct Cora *co) {
   Obj this = co->args[0];
   Obj cont = nativeData(this)[0];
 
-  // Discard the stack to the try.
-  int p = contTryMark(cont);
-  co->callstack.len = p;
-
   // Replace the current stack with the delimited continuation.
   struct callStack* cs = contCallStack(cont);
   Obj val = co->args[1];
@@ -428,7 +424,7 @@ builtinThrow(struct Cora *co) {
   assert(try->pos == 1);
 
   // Capture the call stack as continuation.
-  Obj cont = makeContinuation(p);
+  Obj cont = makeContinuation();
   struct callStack* stack = contCallStack(cont);
   for (int i=p; i<co->callstack.len; i++) {
     struct returnAddr *addr = &co->callstack.data[i];

src/types.c

@@ -407,13 +407,6 @@ makeContinuation(int pos) {
   return ((Obj)(&cont->head) | TAG_PTR);
 }
 
-int
-contTryMark(Obj cont) {
-  struct scmContinuation* v = ptr(cont);
-  assert(v->head.type == scmHeadContinuation);
-  return v->pos;
-}
-
 struct callStack*
 contCallStack(Obj cont) {
   struct scmContinuation* v = ptr(cont);

src/types.h

@@ -126,7 +126,6 @@ struct callStack {
 
 Obj makeContinuation();
 struct callStack* contCallStack(Obj cont);
-int contTryMark(Obj cont);
 
 void gcMarkCallStack(struct GC *gc, struct callStack *stack);
 

test/r/discard-handler-stack.result

@@ -1 +1 @@
-708
+709

test/t/closure-ref.cora

@@ -1 +1,5 @@
-667
+((lambda (x y)
+	(try (lambda ()
+		(+ x (throw 'ignore)))
+	    (lambda (v resume) (resume y))))
+	666 1)

test/t/discard-handler-stack.cora

@@ -2,10 +2,8 @@
        (let fd (throw 'Accept)
 	    (begin
 	     (throw 'Spawn)
-	     (+ fd 42))))
+	     (+ fd 1))))
      (lambda (v k)
        (match v
-	      'Accept (begin
-		       (k 666)
-		       42)
-	      'Spawn (k ()))))
+	      'Accept (+ (k 666) 42)
+	      'Spawn (k ()))))

test/t/recover-multiple-times.cora

@@ -1 +1 @@
-2
+(try (lambda () (do (throw 1) (throw 2))) (lambda (v cc) (cc v)))

test/t/resume-in-closure-call.cora

@@ -1 +1,4 @@
-44
+(do (set 'f (lambda (a b) (+ a b)))
+    (try (lambda ()
+	   (f (throw 42) 1))
+	 (lambda (v resume) (resume (+ v 1)))))