Fix inconsistent synchronization of NamespaceResolver.pointer; locked

50% of time (SpotBugs: MT_CORRECTNESS IS2_INCONSISTENT_SYNC)

Author: garydgregory

src/changes/changes.xml

@@ -52,6 +52,7 @@ The <action> type attribute can be add,update,fix,remove.
       <action type="fix" dev="ggregory" due-to="Gary Gregory">POM assembly:single does not generate binary convenience files (tar/zip).</action>
       <action type="fix" dev="ggregory" due-to="Dima1224, Gary Gregory">Make dynamicPropertyHandlerMap in ValueUtils thread-safe #251.</action>
       <action type="fix" dev="ggregory" due-to="Gary Gregory">Refactor JXPathIntrospector internal static maps to use concurrent classes instead of synchronization.</action>
+      <action type="fix" dev="ggregory" due-to="Gary Gregory">Fix inconsistent synchronization of NamespaceResolver.pointer; locked 50% of time (SpotBugs: MT_CORRECTNESS IS2_INCONSISTENT_SYNC).</action>
       <!-- ADD -->
       <!-- UPDATE -->
       <action type="update" dev="ggregory" due-to="Gary Gregory, Dependabot">Bump org.apache.commons:commons-parent from 81 to 92 #239, #262, #265.</action>

src/main/java/org/apache/commons/jxpath/ri/NamespaceResolver.java

@@ -133,7 +133,7 @@ protected synchronized String getExternallyRegisteredPrefix(final String namespa
      *
      * @return Pointer
      */
-    public Pointer getNamespaceContextPointer() {
+    public synchronized Pointer getNamespaceContextPointer() {
         if (pointer == null && parent != null) {
             return parent.getNamespaceContextPointer();
         }
@@ -201,7 +201,7 @@ public void seal() {
      *
      * @param pointer the Pointer to set.
      */
-    public void setNamespaceContextPointer(final NodePointer pointer) {
+    public synchronized void setNamespaceContextPointer(final NodePointer pointer) {
         this.pointer = pointer;
     }
 }