Extract Interface: Fix NPE on dialog opening

#KT-14854 Fixed

ChangeLog.md

@@ -335,6 +335,7 @@ These artifacts include extensions for the types available in the latter JDKs, s
 #### Refactorings
 
 - [`KT-14583`](https://youtrack.jetbrains.com/issue/KT-14583) Change Signature: Use new signature when looking for redeclaration conflicts
+- [`KT-14854`](https://youtrack.jetbrains.com/issue/KT-14854) Extract Interface: Fix NPE on dialog opening
 
 ## 1.0.5
 

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/extractClass/ui/KotlinExtractSuperDialogBase.kt

@@ -51,6 +51,8 @@ abstract class KotlinExtractSuperDialogBase(
         refactoringName: String,
         private val refactoring: (ExtractSuperInfo) -> Unit
 ) : JavaExtractSuperBaseDialog(originalClass.project, originalClass.toLightClass()!!, emptyList(), refactoringName) {
+    private var initComplete: Boolean = false
+
     private lateinit var memberInfoModel: MemberInfoModelBase
 
     val selectedMembers: List<KotlinMemberInfo>
@@ -73,6 +75,7 @@ abstract class KotlinExtractSuperDialogBase(
         get() = fileNameField.text
 
     private fun resetFileNameField() {
+        if (!initComplete) return
         fileNameField.text = "$extractedSuperName.${KotlinFileType.EXTENSION}"
     }
 
@@ -146,6 +149,8 @@ abstract class KotlinExtractSuperDialogBase(
     override fun init() {
         super.init()
 
+        initComplete = true
+
         resetFileNameField()
     }