Index: openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl,v
diff -u -r1.72.2.27 -r1.72.2.28
--- openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	15 Jul 2015 09:01:35 -0000	1.72.2.27
+++ openacs-4/packages/xotcl-core/tcl/01-debug-procs.tcl	15 Dec 2018 18:07:48 -0000	1.72.2.28
@@ -576,6 +576,15 @@
     #
     ns_log notice "ON DELETE $args"
     ::xo::broadcast clear
+
+    #
+    # Make sure, no handles are allocated any more. Otherwise, when
+    # the thread is reused, there would be a conflict, when the thread
+    # has already a handle associated but tries to obtain an
+    # additional handle.
+    #
+    db_release_unused_handles
+    
     set t0 [clock clicks -milliseconds]
     ::xo::system_stats recordtimes
     #