[bugfix] Previously modules of modules were reset with the wrong

context, this meant that not all resources stored in context variables were correctly cleaned up, therefore leaking resources and memory. In addition reset was previously called more than once for the same module which was unecessary.
Closes #3889

Author: adamretter

exist-core/src/main/java/org/exist/xquery/XQueryContext.java

@@ -209,7 +209,7 @@ public class XQueryContext implements BinaryValueManager, Context {
     protected XQueryWatchDog watchdog;
 
     /**
-     * Loaded modules.
+     * Loaded modules within this module.
      *
      * The format of the map is: <code>Map&lt;NamespaceURI, Modules&gt;</code>.
      */
@@ -1402,7 +1402,13 @@ public void reset(final boolean keepGlobals) {
             watchdog.reset();
         }
 
-        for (final Module[] modules : allModules.values()) {
+        /*
+            NOTE: we use `modules` (and not `allModules`) here so as to only reset
+            the modules of this module.
+            The inner call to `module.reset` will be called on sub-modules
+            which in-turn will reset their modules, and so on.
+         */
+        for (final Module[] modules : modules.values()) {
             for (final Module module : modules) {
                 module.reset(this, keepGlobals);
             }