[java-inspections] UnrollLoopAction: track class conflicts (IDEA-331850)

GitOrigin-RevId: 314a8f32ca768b18f337bc584b1a8bfe3941248e

java/java-impl/src/com/intellij/codeInsight/intention/impl/UnrollLoopAction.java

@@ -256,12 +256,17 @@ public class UnrollLoopAction extends PsiUpdateModCommandAction<PsiLoopStatement
       if (statement instanceof PsiDeclarationStatement declaration) {
         if (expressions.size() > 1) return false;
         for (PsiElement element : declaration.getDeclaredElements()) {
+          PsiResolveHelper resolveHelper = PsiResolveHelper.getInstance(block.getProject());
           if (element instanceof PsiVariable variable) {
             String name = variable.getName();
-            if (name != null) {
-              if (PsiResolveHelper.getInstance(block.getProject()).resolveReferencedVariable(name, parentBlock) != null) {
-                return false;
-              }
+            if (name != null && resolveHelper.resolveReferencedVariable(name, parentBlock) != null) {
+              return false;
+            }
+          }
+          if (element instanceof PsiClass psiClass) {
+            String name = psiClass.getName();
+            if (name != null && resolveHelper.resolveReferencedClass(name, parentBlock) != null) {
+              return false;
             }
           }
         }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unrollLoop/afterDeclareConflictClass.java

@@ -0,0 +1,11 @@
+// "Unroll loop" "true-preview"
+class X {
+  void test() {
+      {
+          class Y {
+              int a = 1;
+          }
+      }
+      class Y {}
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unrollLoop/afterDeclareOne.java

@@ -2,6 +2,8 @@
 class X {
   void test() {
       int y = 1 + 1;
+      class Y {
+      }
       System.out.println(y);
   }
 }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unrollLoop/beforeDeclareConflictClass.java

@@ -0,0 +1,11 @@
+// "Unroll loop" "true-preview"
+class X {
+  void test() {
+    <caret>for (int x : new int[]{1}) {
+      class Y {
+        int a = x;
+      }
+    }
+    class Y {}
+  }
+}

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/unrollLoop/beforeDeclareOne.java

@@ -3,6 +3,7 @@ class X {
   void test() {
     <caret>for (int x : new int[]{1}) {
       int y = x + 1;
+      class Y{}
       System.out.println(y);
     }
   }