[java-inspections] Disallow PatternVariableCanBeUsed inspection on upcasting

GitOrigin-RevId: 89f15c8cbcc84d339973bb5ad1978c7409805fa3

java/java-impl/src/com/intellij/codeInspection/PatternVariableCanBeUsedInspection.java

@@ -28,10 +28,14 @@ public class PatternVariableCanBeUsedInspection extends AbstractBaseJavaLocalIns
         if (identifier == null) return;
         PsiTypeCastExpression cast = ObjectUtils.tryCast(PsiUtil.skipParenthesizedExprDown(variable.getInitializer()),
                                                          PsiTypeCastExpression.class);
-        if (cast == null || cast.getOperand() == null || cast.getCastType() == null) return;
+        if (cast == null || cast.getCastType() == null) return;
+        PsiExpression operand = cast.getOperand();
+        if (operand == null) return;
         PsiType castType = cast.getCastType().getType();
         if (castType instanceof PsiPrimitiveType) return;
         if (!variable.getType().equals(castType)) return;
+        PsiType operandType = operand.getType();
+        if (operandType == null || castType.isAssignableFrom(operandType)) return;
         PsiElement scope = PsiUtil.getVariableCodeBlock(variable, null);
         if (scope == null) return;
         PsiDeclarationStatement declaration = ObjectUtils.tryCast(variable.getParent(), PsiDeclarationStatement.class);

java/java-tests/testData/inspection/patternVariableCanBeUsed/beforeUpcast.java

@@ -0,0 +1,9 @@
+// "Replace 'obj' with pattern variable" "false"
+class X {
+  void test(String s) {
+    if (s instanceof Object) {
+      Object <caret>obj = (Object) s;
+      System.out.println(obj);
+    }
+  }
+}