https://svn.savannah.gnu.org/viewvc/texmacs/trunk/src/src/Kernel/Containers/hashtree.cpp?r1=2717&r2=14566&diff_format=u

Index: src/Kernel/Containers/hashtree.cpp
--- src/Kernel/Containers/hashtree.cpp.orig
+++ src/Kernel/Containers/hashtree.cpp
@@ -94,7 +94,7 @@ hashtree<K,V>::operator-> (void) {
 
 template<class K, class V> inline hashtree<K,V> 
 hashtree<K,V>::operator[] (K key) {
-  if (*this->contains (key)) return *this->children (key);
+  if ((*this)->contains (key)) return (*this)->children (key);
   else FAILED ("read-access to non-existent node requested");
 }
   
