Do not suggest adding !! on null constant #KT-14643 Fixed

idea/src/org/jetbrains/kotlin/idea/quickfix/ExclExclCallFixes.kt

@@ -30,6 +30,7 @@ import org.jetbrains.kotlin.diagnostics.Diagnostic
 import org.jetbrains.kotlin.diagnostics.Errors
 import org.jetbrains.kotlin.idea.KotlinBundle
 import org.jetbrains.kotlin.idea.caches.resolve.analyze
+import org.jetbrains.kotlin.idea.intentions.branchedTransformations.isNullExpression
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation
 import org.jetbrains.kotlin.lexer.KtTokens
 import org.jetbrains.kotlin.psi.*
@@ -106,7 +107,10 @@ class AddExclExclCallFix(psiElement: PsiElement, val checkImplicitReceivers: Boo
 
     private fun getExpressionForIntroduceCall(): ExpressionForCall? {
         val psiElement = element ?: return null
-        return if (psiElement is LeafPsiElement && psiElement.elementType == KtTokens.DOT) {
+        return if ((psiElement as? KtExpression).isNullExpression()) {
+            return null
+        }
+        else if (psiElement is LeafPsiElement && psiElement.elementType == KtTokens.DOT) {
             (psiElement.prevSibling as? KtExpression).expressionForCall()
         }
         else if (psiElement is KtArrayAccessExpression) {

idea/testData/quickfix/addExclExclCall/null.kt

@@ -0,0 +1,8 @@
+// "Add non-null asserted (!!) call" "false"
+// ACTION: Add 'const' modifier
+// ACTION: Add 'toString()' call
+// ACTION: Change type of 'x' to 'String?'
+// ACTION: Convert property initializer to getter
+// ERROR: Null can not be a value of a non-null type String
+
+val x: String = null<caret>

idea/tests/org/jetbrains/kotlin/idea/quickfix/QuickFixTestGenerated.java

@@ -266,6 +266,12 @@ public class QuickFixTestGenerated extends AbstractQuickFixTest {
             doTest(fileName);
         }
 
+        @TestMetadata("null.kt")
+        public void testNull() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/addExclExclCall/null.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("operationIn.kt")
         public void testOperationIn() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/quickfix/addExclExclCall/operationIn.kt");