Elvis -> if intention: don't introduce new variable when RHS type is Nothing

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

@@ -19,8 +19,10 @@ import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.calls.callUtil.getResolvedCall
+import org.jetbrains.kotlin.resolve.calls.callUtil.getType
 import org.jetbrains.kotlin.resolve.lazy.BodyResolveMode
 import org.jetbrains.kotlin.types.TypeUtils
+import org.jetbrains.kotlin.types.typeUtil.isNothing
 
 class ElvisToIfThenIntention : SelfTargetingRangeIntention<KtBinaryExpression>(
     KtBinaryExpression::class.java,
@@ -71,9 +73,12 @@ class ElvisToIfThenIntention : SelfTargetingRangeIntention<KtBinaryExpression>(
         if (leftSafeCastReceiver == null) {
             val property = (KtPsiUtil.safeDeparenthesize(element).parent as? KtProperty)
             val propertyName = property?.name
-            if ((right is KtReturnExpression || right is KtBreakExpression || right is KtContinueExpression || right is KtThrowExpression)
-                && propertyName != null
-            ) {
+            val rightIsReturnOrJumps = right is KtReturnExpression
+                    || right is KtBreakExpression
+                    || right is KtContinueExpression
+                    || right is KtThrowExpression
+                    || right.getType(context)?.isNothing() == true
+            if (rightIsReturnOrJumps && propertyName != null) {
                 val parent = property.parent
                 val factory = KtPsiFactory(element)
                 factory.createExpressionByPattern("if ($0 == null) $1", propertyName, right)

idea/testData/intentions/branched/elvisToIfThen/assignmentAndError.kt

@@ -0,0 +1,5 @@
+// WITH_RUNTIME
+fun foo(list: List<String>): String {
+    val first = list.firstOrNull() ?:<caret> error("empty")
+    return "First length: ${first.length}"
+}

idea/testData/intentions/branched/elvisToIfThen/assignmentAndError.kt.after

@@ -0,0 +1,6 @@
+// WITH_RUNTIME
+fun foo(list: List<String>): String {
+    val first = list.firstOrNull()
+    if (first == null) error("empty")
+    return "First length: ${first.length}"
+}

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

@@ -2279,6 +2279,11 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
                 runTest("idea/testData/intentions/branched/elvisToIfThen/assignmentAndContinue.kt");
             }
 
+            @TestMetadata("assignmentAndError.kt")
+            public void testAssignmentAndError() throws Exception {
+                runTest("idea/testData/intentions/branched/elvisToIfThen/assignmentAndError.kt");
+            }
+
             @TestMetadata("assignmentAndReturn.kt")
             public void testAssignmentAndReturn() throws Exception {
                 runTest("idea/testData/intentions/branched/elvisToIfThen/assignmentAndReturn.kt");