IDEA-169678 "Replace Optional.isPresent() condition with functional style expression" breaks code in case of 'Collection' return type

java/java-impl/src/com/intellij/codeInspection/util/OptionalUtil.java

@@ -136,7 +136,7 @@ public class OptionalUtil {
       }
       trueExpression =
         targetType == null ? trueExpression : RefactoringUtil.convertInitializerToNormalExpression(trueExpression, targetType);
-      String typeArg = getMapTypeArgument(trueExpression, targetType);
+      String typeArg = getMapTypeArgument(trueExpression, targetType, falseExpression);
       qualifier += "." + typeArg + "map(" + LambdaUtil.createLambda(var, trueExpression) + ")";
     }
     if (useOrElseGet && !ExpressionUtils.isSimpleExpression(falseExpression)) {
@@ -154,6 +154,11 @@ public class OptionalUtil {
 
   @NotNull
   public static String getMapTypeArgument(PsiExpression expression, PsiType type) {
+    return getMapTypeArgument(expression, type, null);
+  }
+
+  @NotNull
+  private static String getMapTypeArgument(PsiExpression expression, PsiType type, PsiExpression falseExpression) {
     if (!(type instanceof PsiClassType)) return "";
     PsiExpression copy =
       JavaPsiFacade.getElementFactory(expression.getProject()).createExpressionFromText(expression.getText(), expression);
@@ -162,7 +167,9 @@ public class OptionalUtil {
         !exprType.equals(PsiType.NULL) &&
         !LambdaUtil.notInferredType(exprType) &&
         TypeConversionUtil.isAssignable(type, exprType)) {
-      return "";
+      if (falseExpression == null) return "";
+      PsiType falseType = falseExpression.getType();
+      if (falseType != null && falseType.isAssignableFrom(exprType)) return "";
     }
     return "<" + type.getCanonicalText() + ">";
   }

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

@@ -0,0 +1,18 @@
+// "Replace Optional.isPresent() condition with functional style expression" "true"
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Optional;
+import java.util.Set;
+
+public class TestFile {
+
+  public static Collection<String> example() {
+    final Optional<String> root = Optional.empty();
+      return root.<Collection<String>>map(TestFile::foo).orElseGet(Collections::emptyList);
+  }
+
+  private static Set<String> foo(String s) {
+    return Collections.emptySet();
+  }
+}

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

@@ -0,0 +1,21 @@
+// "Replace Optional.isPresent() condition with functional style expression" "true"
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.Optional;
+import java.util.Set;
+
+public class TestFile {
+
+  public static Collection<String> example() {
+    final Optional<String> root = Optional.empty();
+    if (root<caret>.isPresent()) {
+      return foo(root.get());
+    }
+    return Collections.emptyList();
+  }
+
+  private static Set<String> foo(String s) {
+    return Collections.emptySet();
+  }
+}