If then to elvis: handle nullability even with implicit receiver

So #KT-22741 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/branchedTransformations/intentions/IfThenToElvisIntention.kt

@@ -46,14 +46,19 @@ class IfThenToElvisIntention : SelfTargetingOffsetIndependentIntention<KtIfExpre
     "Replace 'if' expression with elvis expression"
 ) {
 
-    private fun IfThenToSelectData.clausesReplaceableByElvis(): Boolean {
-        if (baseClause == null || negatedClause == null || negatedClause.isNullOrBlockExpression()) return false
-        if (negatedClause is KtThrowExpression && negatedClause.throwsNullPointerExceptionWithNoArguments()) return false
-
-        return receiverExpression is KtThisExpression && hasImplicitReceiver() ||
-                baseClause.evaluatesTo(receiverExpression) ||
-                baseClause.hasFirstReceiverOf(receiverExpression) && !baseClause.hasNullableType(context)
-    }
+    private fun IfThenToSelectData.clausesReplaceableByElvis(): Boolean =
+        when {
+            baseClause == null || negatedClause == null || negatedClause.isNullOrBlockExpression() ->
+                false
+            negatedClause is KtThrowExpression && negatedClause.throwsNullPointerExceptionWithNoArguments() ->
+                false
+            baseClause.evaluatesTo(receiverExpression) ->
+                true
+            receiverExpression is KtThisExpression && hasImplicitReceiver() || baseClause.hasFirstReceiverOf(receiverExpression) ->
+                !baseClause.hasNullableType(context)
+            else ->
+                false
+        }
 
     override fun isApplicableTo(element: KtIfExpression): Boolean {
         val ifThenToSelectData = element.buildSelectTransformationData() ?: return false

idea/testData/intentions/branched/ifThenToElvis/nullableResultWithImplicitReceiver.kt

@@ -0,0 +1,7 @@
+// IS_APPLICABLE: false
+
+class Something {
+    fun nullable(): Int? = null
+}
+fun Something?.nullable(value: Int): Int? =
+    <caret>if (this == null) value else nullable()

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

@@ -2358,6 +2358,11 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 runTest("idea/testData/intentions/branched/ifThenToElvis/nullCheckWithSelectorCallChain.kt");
             }
 
+            @TestMetadata("nullableResultWithImplicitReceiver.kt")
+            public void testNullableResultWithImplicitReceiver() throws Exception {
+                runTest("idea/testData/intentions/branched/ifThenToElvis/nullableResultWithImplicitReceiver.kt");
+            }
+
             @TestMetadata("nullableThen.kt")
             public void testNullableThen() throws Exception {
                 runTest("idea/testData/intentions/branched/ifThenToElvis/nullableThen.kt");