Fix some false positives in UnusedPrivateField

pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/unusedcode/UnusedPrivateFieldRule.java

@@ -80,30 +80,26 @@ public class UnusedPrivateFieldRule extends AbstractJavaRule {
         nodes.addAll(enumConstants);
 
         for (JavaNode node : nodes) {
-            for (int i = 0; i < node.jjtGetNumChildren(); i++) {
+            List<ASTPrimarySuffix> primarySuffixes = node.findDescendantsOfType(ASTPrimarySuffix.class);
-                if (node.jjtGetChild(i) instanceof ASTClassOrInterfaceDeclaration) {
-                    continue; // Skip other inner classes
-                }
-
-                List<ASTPrimarySuffix> primarySuffixes = node
-                        .findDescendantsOfType(ASTPrimarySuffix.class);
             for (ASTPrimarySuffix primarySuffix : primarySuffixes) {
                 if (decl.getImage().equals(primarySuffix.getImage())) {
                     return true; // No violation
                 }
             }
 
-                List<ASTPrimaryPrefix> primaryPrefixes = node
+            List<ASTPrimaryPrefix> primaryPrefixes = node.findDescendantsOfType(ASTPrimaryPrefix.class);
-                        .findDescendantsOfType(ASTPrimaryPrefix.class);
             for (ASTPrimaryPrefix primaryPrefix : primaryPrefixes) {
                 ASTName name = primaryPrefix.getFirstDescendantOfType(ASTName.class);
 
-                    if (name != null && name.getImage().endsWith(decl.getImage())) {
+                if (name != null) {
+                    for (String id : name.getImage().split("\\.")) {
+                        if (id.equals(decl.getImage())) {
                             return true; // No violation
                         }
                     }
                 }
             }
+        }
         return false;
     }
 

pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/unusedcode/xml/UnusedPrivateField.xml

@@ -388,6 +388,40 @@ public enum Operation
         private static final int PRIVATE_STAY = 0;
         private static final int PRIVATE_MOVE = 1;
     }
+}
+        ]]></code>
+    </test-code>
+    <test-code>
+        <description><![CDATA[
+private field in inner class accessed as method call
+     ]]></description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class InnerPrivateFieldCall {
+    int method() {
+        return Inner.FIELD.length();
+    }
+    static class Inner {
+        private static final String FIELD = "";
+    }
+}
+     ]]></code>
+    </test-code>
+    <test-code>
+        <description><![CDATA[
+private field in inner class accessed by another inner class
+     ]]></description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+public class InnerPrivateFieldInAnotherInner {
+    static class InnerUsing {
+        int method() {
+            return InnerDeclaring.INNER_FIELD;
+        }
+    }
+    static class InnerDeclaring {
+        private static int INNER_FIELD;
+    }
 }
      ]]></code>
     </test-code>