Smart completion: function literal argument can correspond only to the last parameter!

idea/idea-completion/src/org/jetbrains/kotlin/idea/completion/ExpectedInfos.kt

@@ -183,13 +183,11 @@ class ExpectedInfos(
 
             val expectedName = if (descriptor.hasSynthesizedParameterNames()) null else parameter.getName().asString()
 
-            val lastNonOptionalParam = parameters.lastOrNull { !it.hasDefaultValue() }
-
             fun needCommaForParameter(parameter: ValueParameterDescriptor): Boolean {
                 if (parameter.hasDefaultValue()) return false // parameter is optional
                 if (parameter.getVarargElementType() != null) return false // vararg arguments list can be empty
-                // last non-optional parameter of functional type can be placed outside parenthesis:
-                if (parameter == lastNonOptionalParam && KotlinBuiltIns.isFunctionOrExtensionFunctionType(parameter.getType())) return false
+                // last parameter of functional type can be placed outside parenthesis:
+                if (parameter == parameters.last() && KotlinBuiltIns.isFunctionOrExtensionFunctionType(parameter.getType())) return false
                 return true
             }
 

idea/idea-completion/testData/handlers/smart/LastNonOptionalParamIsFunction.kt.after

@@ -1,7 +1,7 @@
 fun foo(p: Int, handler: () -> Unit, optional: String = ""){}
 
 fun bar(p: Int) {
-    foo(p<caret>)
+    foo(p, <caret>)
 }
 
 // ELEMENT: p

idea/idea-completion/testData/handlers/smart/LastParamIsFunction.kt

@@ -0,0 +1,7 @@
+fun foo(p: Int, handler: () -> Unit){}
+
+fun bar(p: Int) {
+    foo(<caret>)
+}
+
+// ELEMENT: p

idea/idea-completion/testData/handlers/smart/LastParamIsFunction.kt.after

@@ -0,0 +1,7 @@
+fun foo(p: Int, handler: () -> Unit){}
+
+fun bar(p: Int) {
+    foo(p<caret>)
+}
+
+// ELEMENT: p

idea/idea-completion/tests/org/jetbrains/kotlin/idea/completion/test/handlers/SmartCompletionHandlerTestGenerated.java

@@ -485,6 +485,12 @@ public class SmartCompletionHandlerTestGenerated extends AbstractSmartCompletion
         doTest(fileName);
     }
 
+    @TestMetadata("LastParamIsFunction.kt")
+    public void testLastParamIsFunction() throws Exception {
+        String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/handlers/smart/LastParamIsFunction.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("MergeTail1.kt")
     public void testMergeTail1() throws Exception {
         String fileName = JetTestUtils.navigationMetadata("idea/idea-completion/testData/handlers/smart/MergeTail1.kt");