[TRINIDAD-2421] NullPointerException when property not resolvable through -tr-property-ref

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0.1-core
• Fix Version/s: 2.1.0-core
• Component/s: Skinning
• Assignee: Jeanne Waldman
• Reporter: Prakash Udupa
• Created: 18/Oct/13 15:42
• Updated: 14/Nov/13 17:31
• Resolved: 21/Oct/13 17:10

Description

The bug:
-----------
Suppose in an application's skin file there is a selector definition with a custom skin property '-tr-cjk-font-family' like the following:

tr|mySelectorInternal::title{
-tr-cjk-font-family: -tr-property-ref("tr|mySelector","font-family");
}

...and then "font-family" is not defined anywhere for the selector "tr|mySelector". This will lead to the following NPE...

java.lang.NullPointerException
at java.util.concurrent.ConcurrentHashMap.put(ConcurrentHashMap.java:881)
at org.apache.myfaces.trinidadinternal.style.cache.FileSystemStyleCache._getStyleContextResolvedSkinProperties(FileSystemStyleCache.java:790)
at org.apache.myfaces.trinidadinternal.style.cache.FileSystemStyleCache._createEntry(FileSystemStyleCache.java:605)
at org.apache.myfaces.trinidadinternal.style.cache.FileSystemStyleCache._getEntry(FileSystemStyleCache.java:465)
at org.apache.myfaces.trinidadinternal.style.cache.FileSystemStyleCache.getStyleSheetURIs(FileSystemStyleCache.java:183)...

And when this NPE happens, applications are completely broken.

It is perfectly fine for a property to not resolve through tr-property-ref due to missing dependencies, it is the skinning framework code that should handle this case gracefully. We should just not try to add a null value to ConcurrentHashMap in the above code path.

I'll attach a patch with simple code addition that does a not-null check to cover this case.