From af30f4cef92d882d253ee2f0c9d5144737412635 Mon Sep 17 00:00:00 2001
From: Oleg Andreych <kjiec4@gmail.com>
Date: Sun, 18 Sep 2022 15:29:50 +0500
Subject: [PATCH] False-positive UnnecessaryFullyQualifiedName when nested and
 non-nested classes with the same name and in the same package are used
 together #4085

* Regression fix;
---
 .../UnnecessaryFullyQualifiedNameRule.java        | 10 +++++-----
 .../xml/UnnecessaryFullyQualifiedName.xml         | 15 +++++++++++++++
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/codestyle/UnnecessaryFullyQualifiedNameRule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/codestyle/UnnecessaryFullyQualifiedNameRule.java
index 36773e3a91..5348abca59 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/codestyle/UnnecessaryFullyQualifiedNameRule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/rule/codestyle/UnnecessaryFullyQualifiedNameRule.java
@@ -188,10 +188,11 @@ public class UnnecessaryFullyQualifiedNameRule extends AbstractJavaRule {
 
         if (matches.isEmpty()) {
             if (isJavaLangImplicit(node)) {
-                addViolation(data, node, new Object[]{node.getImage(), "java.lang.*", "implicit "});
+                asCtx(data).addViolation(node,
+                        node.getImage(), "java.lang.*", "implicit ");
             } else if (isSamePackage(node, name)) {
                 if (!hasSameSimpleNameInScope(node)) {
-                    addViolation(data, node, new Object[]{node.getImage(), currentPackage + ".*", "same package "});
+                    asCtx(data).addViolation(node, node.getImage(), currentPackage + ".*", "same package ");
                 }
             }
         } else {
@@ -217,10 +218,9 @@ public class UnnecessaryFullyQualifiedNameRule extends AbstractJavaRule {
             return false;
         }
 
-        final String nodeSimpleName = nodeType.getSimpleName();
-
         for (ASTClassOrInterfaceDeclaration declarationDescendant : declarationDescendants) {
-            if (nodeSimpleName.equals(declarationDescendant.getSimpleName())) {
+            if (nodeType.getSimpleName().equals(declarationDescendant.getSimpleName())
+                    && !nodeType.getName().equals(declarationDescendant.getQualifiedName().toString())) {
                 return true;
             }
         }
diff --git a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/codestyle/xml/UnnecessaryFullyQualifiedName.xml b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/codestyle/xml/UnnecessaryFullyQualifiedName.xml
index 865f62c789..426bb9b4b6 100644
--- a/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/codestyle/xml/UnnecessaryFullyQualifiedName.xml
+++ b/pmd-java/src/test/resources/net/sourceforge/pmd/lang/java/rule/codestyle/xml/UnnecessaryFullyQualifiedName.xml
@@ -641,6 +641,21 @@ public class OuterTestClass {
         ]]></code>
     </test-code>
 
+    <test-code>
+        <description>Should report fully-qualified name usage of a class in itself.</description>
+        <expected-problems>1</expected-problems>
+        <expected-linenumbers>4</expected-linenumbers>
+        <code><![CDATA[
+package net.sourceforge.pmd.lang.java.rule.codestyle.unnecessaryfullyqualifiedname;
+
+public class TestClass {
+    public static net.sourceforge.pmd.lang.java.rule.codestyle.unnecessaryfullyqualifiedname.TestClass INSTANCE(){
+        return new TestClass();
+    }
+}
+        ]]></code>
+    </test-code>
+
     <test-code>
         <description>#2098 false positive with annotated package</description>
         <expected-problems>0</expected-problems>