KT-510 this. allows initialization without backing field

compiler/frontend/src/org/jetbrains/jet/lang/cfg/JetFlowInformationProvider.java

@@ -285,11 +285,19 @@ public class JetFlowInformationProvider {
                             varWithValReassignErrorGenerated.add(variableDescriptor);
                             trace.report(Errors.VAL_REASSIGNMENT.on(expression, variableDescriptor, property == null ? new JetProperty[0] : new JetProperty[] { property }));
                         }
-                        if (expression instanceof JetSimpleNameExpression && inAnonymousInitializers &&
-                            variableDescriptor instanceof PropertyDescriptor && !enterInitializationPoints.isInitialized() && exitInitializationPoints.isInitialized()) {
-                            JetSimpleNameExpression simpleNameExpression = (JetSimpleNameExpression) expression;
-                            if (simpleNameExpression.getReferencedNameElementType() != JetTokens.FIELD_IDENTIFIER) {
-                                trace.report(Errors.INITIALIZATION_USING_BACKING_FIELD.on(simpleNameExpression, variableDescriptor));
+                        if (inAnonymousInitializers && variableDescriptor instanceof PropertyDescriptor && !enterInitializationPoints.isInitialized() &&
+                            exitInitializationPoints.isInitialized()) {
+                            JetExpression variable = expression;
+                            if (expression instanceof JetDotQualifiedExpression) {
+                                if (((JetDotQualifiedExpression) expression).getReceiverExpression() instanceof JetThisExpression) {
+                                    variable = ((JetDotQualifiedExpression) expression).getSelectorExpression();
+                                }
+                            }
+                            if (variable instanceof JetSimpleNameExpression) {
+                                JetSimpleNameExpression simpleNameExpression = (JetSimpleNameExpression) variable;
+                                if (simpleNameExpression.getReferencedNameElementType() != JetTokens.FIELD_IDENTIFIER) {
+                                    trace.report(Errors.INITIALIZATION_USING_BACKING_FIELD.on(simpleNameExpression, expression, variableDescriptor));
+                                }
                             }
                         }
                     }

compiler/testData/checkerWithErrorTypes/quick/regressions/kt510.jet

@@ -0,0 +1,18 @@
+//KT-510 `this.` allows initialization without backing field
+
+namespace kt510
+
+public open class Identifier1() {
+    var field : Boolean
+    {
+        <!INITIALIZATION_USING_BACKING_FIELD!>field<!> = false; // error
+    }
+}
+
+
+public open class Identifier2() {
+    var field : Boolean
+    {
+        <!INITIALIZATION_USING_BACKING_FIELD!>this.field<!> = false;
+    }
+}

idea/src/org/jetbrains/jet/plugin/quickfix/ChangeToBackingFieldFix.java

@@ -6,9 +6,12 @@ import com.intellij.psi.PsiFile;
 import com.intellij.util.IncorrectOperationException;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.diagnostics.DiagnosticWithPsiElement;
+import org.jetbrains.jet.lang.psi.JetDotQualifiedExpression;
 import org.jetbrains.jet.lang.psi.JetPsiFactory;
 import org.jetbrains.jet.lang.psi.JetSimpleNameExpression;
+import org.jetbrains.jet.lang.psi.JetThisExpression;
 import org.jetbrains.jet.plugin.JetBundle;
+import org.jetbrains.jet.plugin.references.JetThisReference;
 
 /**
  * @author svtk
@@ -33,7 +36,12 @@ public class ChangeToBackingFieldFix extends JetIntentionAction<JetSimpleNameExp
     @Override
     public void invoke(@NotNull Project project, Editor editor, PsiFile file) throws IncorrectOperationException {
         JetSimpleNameExpression backingField = (JetSimpleNameExpression) JetPsiFactory.createExpression(project, "$" + element.getText());
-        element.replace(backingField);
+        if (element.getParent() instanceof JetDotQualifiedExpression && ((JetDotQualifiedExpression) element.getParent()).getReceiverExpression() instanceof JetThisExpression) {
+            element.getParent().replace(backingField);
+        }
+        else {
+            element.replace(backingField);
+        }
     }
 
     public static JetIntentionActionFactory<JetSimpleNameExpression> createFactory() {

idea/testData/quickfix/variables/changeToBackingField/afterKt510.kt

@@ -0,0 +1,7 @@
+// "Change reference to backing field" "true"
+public open class Identifier() {
+    var field : Boolean
+    {
+        <caret>$field = false;
+    }
+}

idea/testData/quickfix/variables/changeToBackingField/beforeKt510.kt

@@ -0,0 +1,7 @@
+// "Change reference to backing field" "true"
+public open class Identifier() {
+    var field : Boolean
+    {
+        <caret>this.field = false;
+    }
+}