Fix bug in move assignment operator.

Author: kpeeters

ChangeLog

@@ -1,3 +1,10 @@
+2020-11-07  Kasper Peeters  <[email protected]>
+
+	* Release 3.16
+
+	* Fix error in move assignment operator which caused tree
+	corruptioin (thanks to Trevor Hickey for reporting the bug).
+
 2020-10-26  Kasper Peeters  <[email protected]>
 
 	* Release 3.15
@@ -6,7 +13,7 @@
 	of calling them directly.
 
 	* Make `parent` throw an exception rather than bailing out with an
-	assert. 
+	assert.
 
 2019-09-21  Kasper Peeters  <[email protected]>
 

src/tree.hh

@@ -9,8 +9,8 @@
 
 /** \mainpage tree.hh
     \author   Kasper Peeters
-    \version  3.15
-    \date     26-Nov-2020
+    \version  3.16
+    \date     07-Nov-2020
     \see      http://tree.phi-sci.com/
     \see      http://github.com/kpeeters/tree.hh/
 
@@ -637,7 +637,7 @@ tree<T,tree_node_allocator>& tree<T, tree_node_allocator>::operator=(tree<T, tre
 		clear(); // clear any existing data.
 
 		head->next_sibling=x.head->next_sibling;
-		feet->prev_sibling=x.head->prev_sibling;
+		feet->prev_sibling=x.feet->prev_sibling;
 		x.head->next_sibling->prev_sibling=head;
 		x.feet->prev_sibling->next_sibling=feet;
 		x.head->next_sibling=x.feet;