[apex] UnusedLocalVariable - false positive on case insensitivity allowed in Apex

Fixes #2626

docs/pages/release_notes.md

@@ -16,6 +16,9 @@ This is a {{ site.pmd.release_type }} release.
 
 ### Fixed Issues
 
+*   apex-bestpractices
+    *   [#2626](https://github.com/pmd/pmd/issues/2626): \[apex] UnusedLocalVariable - false positive on case insensitivity allowed in Apex
+
 ### API Changes
 
 ### External Contributions

pmd-apex/src/main/java/net/sourceforge/pmd/lang/apex/rule/bestpractices/UnusedLocalVariableRule.java

@@ -1,4 +1,4 @@
-/**
+/*
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html
  */
 
@@ -41,7 +41,7 @@ public class UnusedLocalVariableRule extends AbstractApexRule {
                 continue;
             }
 
-            if (usage.hasImageEqualTo(variableName)) {
+            if (equalsIgnoreCase(variableName, usage.getImage())) {
                 return data;
             }
         }
@@ -49,4 +49,14 @@ public class UnusedLocalVariableRule extends AbstractApexRule {
         addViolation(data, node, variableName);
         return data;
     }
+
+    private static boolean equalsIgnoreCase(String a, String b) {
+        if (a == b) {
+            return true;
+        }
+        if (a == null || b == null) {
+            return false;
+        }
+        return a.equalsIgnoreCase(b);
+    }
 }

pmd-apex/src/test/resources/net/sourceforge/pmd/lang/apex/rule/bestpractices/xml/UnusedLocalVariable.xml

@@ -94,6 +94,20 @@ public class Foo {
 trigger leadOwnerUpdate on Lead (after update) {
     for(Lead Id : Trigger.new) {
     }
+}
+        ]]></code>
+    </test-code>
+
+    <test-code>
+        <description>[apex] UnusedLocalVariable - false positive on case insensitivity allowed in Apex #2626</description>
+        <expected-problems>0</expected-problems>
+        <code><![CDATA[
+class Foo {
+    private String foo() {
+        String Bar;
+        bar = 'bar';
+        return bar;
+    }
 }
         ]]></code>
     </test-code>