Program: 18834
Project: 18834
Buggy source:
/** 
 * Given a constructor type and a property name, check that the property has the JSDoc annotation @override iff the property is declared on a superclass. Several checks regarding inheritance correctness are also performed.
 */
private void checkDeclaredPropertyInheritance(NodeTraversal t,Node n,FunctionType ctorType,String propertyName,JSDocInfo info,JSType propertyType){
  if (hasUnknownOrEmptySupertype(ctorType)) {
    return;
  }
  FunctionType superClass=ctorType.getSuperClassConstructor();
  boolean superClassHasProperty=superClass != null && superClass.getPrototype().hasProperty(propertyName);
  boolean declaredOverride=info != null && info.isOverride();
  boolean foundInterfaceProperty=false;
  if (ctorType.isConstructor()) {
    for (    JSType implementedInterface : ctorType.getImplementedInterfaces()) {
      if (implementedInterface.isUnknownType() || implementedInterface.isEmptyType()) {
        continue;
      }
      FunctionType interfaceType=implementedInterface.toObjectType().getConstructor();
      Preconditions.checkNotNull(interfaceType);
      boolean interfaceHasProperty=interfaceType.getPrototype().hasProperty(propertyName);
      foundInterfaceProperty=foundInterfaceProperty || interfaceHasProperty;
      if (reportMissingOverride.isOn() && !declaredOverride && interfaceHasProperty) {
        compiler.report(t.makeError(n,reportMissingOverride,HIDDEN_INTERFACE_PROPERTY,propertyName,interfaceType.getTopMostDefiningType(propertyName).toString()));
      }
      if (interfaceHasProperty) {
        JSType interfacePropType=interfaceType.getPrototype().getPropertyType(propertyName);
        if (!propertyType.canAssignTo(interfacePropType)) {
          compiler.report(t.makeError(n,HIDDEN_INTERFACE_PROPERTY_MISMATCH,propertyName,interfaceType.getTopMostDefiningType(propertyName).toString(),interfacePropType.toString(),propertyType.toString()));
        }
      }
    }
  }
  if (!declaredOverride && !superClassHasProperty) {
    return;
  }
  JSType topInstanceType=superClassHasProperty ? superClass.getTopMostDefiningType(propertyName) : null;
  if (reportMissingOverride.isOn() && ctorType.isConstructor() && !declaredOverride&& superClassHasProperty) {
    compiler.report(t.makeError(n,reportMissingOverride,HIDDEN_SUPERCLASS_PROPERTY,propertyName,topInstanceType.toString()));
  }
  if (!declaredOverride) {
    return;
  }
  if (superClassHasProperty) {
    JSType superClassPropType=superClass.getPrototype().getPropertyType(propertyName);
    if (!propertyType.canAssignTo(superClassPropType)) {
      compiler.report(t.makeError(n,HIDDEN_SUPERCLASS_PROPERTY_MISMATCH,propertyName,topInstanceType.toString(),superClassPropType.toString(),propertyType.toString()));
    }
  }
 else   if (!foundInterfaceProperty) {
    compiler.report(t.makeError(n,UNKNOWN_OVERRIDE,propertyName,ctorType.getInstanceType().toString()));
  }
}

Fixed version (ground truth):
/** 
 * Given a constructor type and a property name, check that the property has the JSDoc annotation @override iff the property is declared on a superclass. Several checks regarding inheritance correctness are also performed.
 */
private void checkDeclaredPropertyInheritance(NodeTraversal t,Node n,FunctionType ctorType,String propertyName,JSDocInfo info,JSType propertyType){
  if (hasUnknownOrEmptySupertype(ctorType)) {
    return;
  }
  FunctionType superClass=ctorType.getSuperClassConstructor();
  boolean superClassHasProperty=superClass != null && superClass.getPrototype().hasProperty(propertyName);
  boolean declaredOverride=info != null && info.isOverride();
  boolean foundInterfaceProperty=false;
  if (ctorType.isConstructor()) {
    for (    JSType implementedInterface : ctorType.getImplementedInterfaces()) {
      if (implementedInterface.isUnknownType() || implementedInterface.isEmptyType()) {
        continue;
      }
      FunctionType interfaceType=implementedInterface.toObjectType().getConstructor();
      Preconditions.checkNotNull(interfaceType);
      boolean interfaceHasProperty=interfaceType.getPrototype().hasProperty(propertyName);
      foundInterfaceProperty=foundInterfaceProperty || interfaceHasProperty;
      if (reportMissingOverride.isOn() && !declaredOverride && interfaceHasProperty) {
        compiler.report(t.makeError(n,reportMissingOverride,HIDDEN_INTERFACE_PROPERTY,propertyName,interfaceType.getTopMostDefiningType(propertyName).toString()));
      }
    }
  }
  if (!declaredOverride && !superClassHasProperty) {
    return;
  }
  JSType topInstanceType=superClassHasProperty ? superClass.getTopMostDefiningType(propertyName) : null;
  if (reportMissingOverride.isOn() && ctorType.isConstructor() && !declaredOverride&& superClassHasProperty) {
    compiler.report(t.makeError(n,reportMissingOverride,HIDDEN_SUPERCLASS_PROPERTY,propertyName,topInstanceType.toString()));
  }
  if (!declaredOverride) {
    return;
  }
  if (superClassHasProperty) {
    JSType superClassPropType=superClass.getPrototype().getPropertyType(propertyName);
    if (!propertyType.canAssignTo(superClassPropType)) {
      compiler.report(t.makeError(n,HIDDEN_SUPERCLASS_PROPERTY_MISMATCH,propertyName,topInstanceType.toString(),superClassPropType.toString(),propertyType.toString()));
    }
  }
 else   if (!foundInterfaceProperty) {
    compiler.report(t.makeError(n,UNKNOWN_OVERRIDE,propertyName,ctorType.getInstanceType().toString()));
  }
}