--- a/ParseNode.st	Sat Aug 24 00:50:45 2019 +0200
+++ b/ParseNode.st	Sat Aug 24 09:20:05 2019 +0200
@@ -133,7 +133,6 @@
         (each intersectsInterval:anInterval) ifTrue:[
             firstChildInInterval notNil ifTrue:[
                 "/ ouch: multiple children in interval
-                self halt.
                 ^ self
             ].
             firstChildInInterval := each
@@ -270,7 +269,7 @@
         "/ self halt.
     ] ifFalse:[
         "/ nil end means: up-to-end (but only for error nodes)
-        self assert:start > 0.
+        self assert:(start notNil and:[start > 0]).
         end isNil ifTrue:[
             self assert:(self isErrorNode)
         ] ifFalse:[