IDEA-211702 Incorrect inspection "Can be replaced with single expression in functional style" when types differ

GitOrigin-RevId: 4006edb212486fa38b31b26ecbed881e6079f6e6

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

@@ -191,10 +191,16 @@ public class OptionalIsPresentInspection extends AbstractBaseJavaLocalInspection
       }
       PsiType falseType = falseExpression.getType();
       PsiType trueType = expression.getType();
-      // like x ? double_expression : integer_expression; support only if integer_expression is simple literal,
-      // so could be converted explicitly to double
-      if (falseType instanceof PsiPrimitiveType && trueType instanceof PsiPrimitiveType &&
-          !falseType.equals(trueType) && JavaPsiMathUtil.getNumberFromLiteral(falseExpression) == null) {
+      if (falseType == null || trueType == null) return ProblemType.NONE;
+      if (falseType instanceof PsiPrimitiveType && trueType instanceof PsiPrimitiveType) {
+        if (falseType.equals(trueType) || JavaPsiMathUtil.getNumberFromLiteral(falseExpression) != null) {
+          // like x ? double_expression : integer_expression; support only if integer_expression is simple literal,
+          // so could be converted explicitly to double
+          return ProblemType.WARNING;
+        }
+        return ProblemType.NONE;
+      }
+      if (!trueType.isAssignableFrom(falseType)) {
         return ProblemType.NONE;
       }
     }

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/quickFix/optionalIsPresent/beforeDifferentReturnTypes.java

@@ -0,0 +1,14 @@
+// "Replace Optional.isPresent() condition with functional style expression" "false"
+import java.util.Optional;
+
+class Test {
+  Object get() {
+    Optional<String> obj = Stream.of("one", "two").filter(s -> Math.sqrt(s.length()) > 100).findFirst();
+    if (obj.<caret>isPresent()) {
+      return obj.get();
+    } else {
+      return 7;
+    }
+  }
+
+}