[FLEX-18852] Incremental Compiles cause RTE due to skin parts not being found/instantiated

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Cannot Reproduce
• Affects Version/s: Adobe Flex SDK Previous
• Component/s: Spark: SkinnableComponent
• Environment: Affected OS(s): All OS Platforms; Language Found: English
• Assignee: Adobe JIRA
• Reporter: Adobe JIRA
• Created: 21/Apr/09 13:20
• Updated: 15/Apr/11 15:18
• Resolved: 04/May/09 00:30

Description

Steps to reproduce:
1. Run the simple app below
2. If it runs okay, touch the spark HScrollBar class and run again (causing an incremental compile, not a full build)

Actual Results:
RTE with stack trace:
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at spark.components::HScrollBar/calculateThumbSize()[C:\Development\ws\Flex4Rename\frameworks\projects\flex4\src\spark\components\HScrollBar.as:153]
at spark.components.supportClasses::TrackBase/updateDisplayList()[C:\Development\ws\Flex4Rename\frameworks\projects\flex4\src\spark\components\supportClasses\TrackBase.as:359]
at mx.core::UIComponent/validateDisplayList()[C:\Development\ws\Flex4Rename\frameworks\projects\framework\src\mx\core\UIComponent.as:7691]
at mx.managers::LayoutManager/validateDisplayList()[C:\Development\ws\Flex4Rename\frameworks\projects\framework\src\mx\managers\LayoutManager.as:657]
at mx.managers::LayoutManager/doPhasedInstantiation()[C:\Development\ws\Flex4Rename\frameworks\projects\framework\src\mx\managers\LayoutManager.as:716]

Expected Results:
Using an HScrollBar in an app should not cause a crash.

Workaround (if any):
Do a clean on the workspace. Also, I've found that touching TrackBase, ScrollBar, andHScrollBar together (forcing a rebuild of all of them) tends to fix the problem.

Application:
<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark">
<s:HScrollBar width="300"/>
</s:Application>