Join declaration & assignment: treat assignment with this. correctly #KT-16000 Fixed

idea/src/org/jetbrains/kotlin/idea/intentions/JoinDeclarationAndAssignmentIntention.kt

@@ -104,7 +104,15 @@ class JoinDeclarationAndAssignmentIntention : SelfTargetingOffsetIndependentInte
         val assignments = mutableListOf<KtBinaryExpression>()
         fun process(binaryExpr: KtBinaryExpression) {
             if (binaryExpr.operationToken != KtTokens.EQ) return
-            val leftReference = binaryExpr.left as? KtNameReferenceExpression ?: return
+            val left = binaryExpr.left
+            val leftReference = when (left) {
+                is KtNameReferenceExpression ->
+                    left
+                is KtDotQualifiedExpression ->
+                    if (left.receiverExpression is KtThisExpression) left.selectorExpression as? KtNameReferenceExpression else null
+                else ->
+                    null
+            } ?: return
             if (leftReference.getReferencedName() != property.name) return
             assignments += binaryExpr
         }

idea/testData/intentions/joinDeclarationAndAssignment/multipleConstructorsWithThis.kt

@@ -0,0 +1,13 @@
+// IS_APPLICABLE: false
+
+class My {
+    val x: Int<caret>
+
+    constructor(x: Int) {
+        this.x = x
+    }
+
+    constructor() {
+        x = 42
+    }
+}

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

@@ -8916,6 +8916,12 @@ public class IntentionTestGenerated extends AbstractIntentionTest {
             doTest(fileName);
         }
 
+        @TestMetadata("multipleConstructorsWithThis.kt")
+        public void testMultipleConstructorsWithThis() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/joinDeclarationAndAssignment/multipleConstructorsWithThis.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("propertyReassignment.kt")
         public void testPropertyReassignment() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("idea/testData/intentions/joinDeclarationAndAssignment/propertyReassignment.kt");