Convert Function Type Parameter to Receiver: Drop redundant arrows

idea/src/org/jetbrains/kotlin/idea/intentions/ConvertFunctionTypeParameterToReceiverIntention.kt

@@ -123,7 +123,11 @@ class ConvertFunctionTypeParameterToReceiverIntention : SelfTargetingRangeIntent
                     for (ref in ReferencesSearch.search(parameterToConvert, LocalSearchScope(expression))) {
                         (ref.element as? KtSimpleNameExpression)?.replace(thisRefExpr)
                     }
-                    expression.functionLiteral.valueParameterList!!.removeParameter(parameterToConvert)
+                    val lambda = expression.functionLiteral
+                    lambda.valueParameterList!!.removeParameter(parameterToConvert)
+                    if (lambda.valueParameters.isEmpty()) {
+                        lambda.arrow?.delete()
+                    }
                 }
                 return
             }

idea/testData/intentions/convertFunctionTypeParameterToReceiver/singleExplicitParameter.kt

@@ -0,0 +1,5 @@
+fun foo(n: Int, action: (<caret>Int) -> Int) = action(n)
+
+fun test() {
+    foo(1) { n -> n + 1 }
+}

idea/testData/intentions/convertFunctionTypeParameterToReceiver/singleExplicitParameter.kt.after

@@ -0,0 +1,5 @@
+fun foo(n: Int, action: Int.(<caret>) -> Int) = n.action()
+
+fun test() {
+    foo(1) { this + 1 }
+}

idea/tests/org/jetbrains/kotlin/idea/intentions/IntentionTestGenerated.java

@@ -4570,6 +4570,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertFunctionTypeParameterToReceiver/overrides.kt");
             doTest(fileName);
         }
+
+        @TestMetadata("singleExplicitParameter.kt")
+        public void testSingleExplicitParameter() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/convertFunctionTypeParameterToReceiver/singleExplicitParameter.kt");
+            doTest(fileName);
+        }
     }
 
     @TestMetadata("idea/testData/intentions/convertFunctionTypeReceiverToParameter")