Introduce Parameter: Do not remove unused parameters if new parameter is extracted with default value

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceParameter/KotlinIntroduceParameterHandler.kt

@@ -94,14 +94,18 @@ public data class IntroduceParameterDescriptor(
         }
         else JetValVar.None
         
-        val occurrenceRanges = occurrencesToReplace.map { it.getTextRange() }
-        parametersToRemove = parametersUsages.entrySet()
-                .filter {
-                    it.value.all { paramRef ->
-                        occurrenceRanges.any { occurrenceRange -> occurrenceRange.contains(paramRef.getElement().getTextRange()) }
-                    }
+        parametersToRemove =
+                if (withDefaultValue) Collections.emptyList()
+                else {
+                    val occurrenceRanges = occurrencesToReplace.map { it.getTextRange() }
+                    parametersUsages.entrySet()
+                            .filter {
+                                it.value.all { paramRef ->
+                                    occurrenceRanges.any { occurrenceRange -> occurrenceRange.contains(paramRef.getElement().getTextRange()) }
+                                }
+                            }
+                            .map { it.key }
                 }
-                .map { it.key }
     }
 }
 

idea/testData/refactoring/introduceParameter/functionMultipleUnusedParameters.kt.after

@@ -1,7 +1,7 @@
-fun foo(s: String, i: Int = a + b): Int {
+fun foo(a: Int, s: String, b: Int, i: Int = a + b): Int {
     return i * 2
 }
 
 fun test() {
-    foo("2")
+    foo(1, "2", 3)
 }

idea/testData/refactoring/introduceParameter/functionMultipleUsages.kt.after

@@ -1,8 +1,8 @@
-fun foo(s: String, i: Int = a + 1): Int {
+fun foo(a: Int, s: String, i: Int = a + 1): Int {
     val t = i * 2
     return i - t
 }
 
 fun test() {
-    foo("2")
+    foo(1, "2")
 }

idea/testData/refactoring/introduceParameter/functionUnusedParameter.kt.after

@@ -1,7 +1,7 @@
-fun foo(s: String, i: Int = a + 1): Int {
+fun foo(a: Int, s: String, i: Int = a + 1): Int {
     return i * 2
 }
 
 fun test() {
-    foo("2")
+    foo(1, "2")
 }