Map.getOrPut: treat nulls as missing values.

idea/idea-core/src/org/jetbrains/kotlin/idea/core/IterableTypesDetection.kt

@@ -32,6 +32,7 @@ import org.jetbrains.kotlin.types.TypeUtils
 import org.jetbrains.kotlin.types.expressions.ExpressionTypingContext
 import org.jetbrains.kotlin.types.expressions.ForLoopConventionsChecker
 import org.jetbrains.kotlin.util.isValidOperator
+import org.jetbrains.kotlin.utils.getOrPutNullable
 import java.util.*
 
 class IterableTypesDetection(
@@ -62,7 +63,7 @@ class IterableTypesDetection(
                 = isIterable(FuzzyType(type, emptyList()), loopVarType)
 
         private fun elementType(type: FuzzyType): FuzzyType? {
-            return cache.getOrPut(type, { elementTypeNoCache(type) })
+            return cache.getOrPutNullable(type, { elementTypeNoCache(type) })
         }
 
         override fun elementType(type: KotlinType): FuzzyType?

idea/src/org/jetbrains/kotlin/idea/refactoring/move/moveTopLevelDeclarations/KotlinMoveTarget.kt

@@ -23,6 +23,7 @@ import com.intellij.psi.PsiManager
 import com.intellij.refactoring.PackageWrapper
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi.KtFile
+import org.jetbrains.kotlin.utils.getOrPutNullable
 import java.util.HashMap
 
 interface KotlinMoveTarget {
@@ -64,7 +65,7 @@ class KotlinMoveTargetForDeferredFile(
 
     override fun getOrCreateTargetPsi(originalPsi: PsiElement): PsiFile? {
         val originalFile = originalPsi.containingFile as? KtFile ?: return null
-        return createdFiles.getOrPut(originalFile) { createFile(originalFile) }
+        return createdFiles.getOrPutNullable(originalFile) { createFile(originalFile) }
     }
 
     override fun getTargetPsiIfExists(originalPsi: PsiElement) = null