Introduce Variable: Fix extraction of expression from when-entry condition

#KT-8444 Fixed

idea/src/org/jetbrains/kotlin/idea/refactoring/introduce/introduceVariable/KotlinIntroduceVariableHandler.java

@@ -558,7 +558,9 @@ public class KotlinIntroduceVariableHandler extends KotlinIntroduceHandlerBase {
                     return parent;
                 }
             }
-            if (parent instanceof JetBlockExpression || parent instanceof JetWhenEntry || parent instanceof JetClassInitializer) {
+            if (parent instanceof JetBlockExpression
+                || (parent instanceof JetWhenEntry && place == ((JetWhenEntry) parent).getExpression())
+                || parent instanceof JetClassInitializer) {
                 return parent;
             }
             if (parent instanceof JetDeclarationWithBody && ((JetDeclarationWithBody) parent).getBodyExpression() == place) {

idea/testData/refactoring/introduceVariable/WhenEntryCondition.kt

@@ -0,0 +1,6 @@
+fun f(x : Int) {
+    val y = if (x < 0) 1 else when {
+        <selection>x - 1</selection> < 1 -> 2
+        else -> 3
+    }
+}

idea/testData/refactoring/introduceVariable/WhenEntryCondition.kt.after

@@ -0,0 +1,9 @@
+fun f(x : Int) {
+    val y = if (x < 0) 1 else {
+        val i = x - 1
+        when {
+            i < 1 -> 2
+            else -> 3
+        }
+    }
+}

idea/tests/org/jetbrains/kotlin/idea/refactoring/introduce/JetExtractionTestGenerated.java

@@ -331,6 +331,12 @@ public class JetExtractionTestGenerated extends AbstractJetExtractionTest {
             doIntroduceVariableTest(fileName);
         }
 
+        @TestMetadata("WhenEntryCondition.kt")
+        public void testWhenEntryCondition() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/introduceVariable/WhenEntryCondition.kt");
+            doIntroduceVariableTest(fileName);
+        }
+
         @TestMetadata("WhenParts.kt")
         public void testWhenParts() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("idea/testData/refactoring/introduceVariable/WhenParts.kt");