<AWT Dev> [8] Review Request: JDK-8026262 NPE in SystemFlavorMap.getAllNativesForType - regression in jdk8 b110 by fix of #JDK-8024987

[Petr Pchelko]

Hello, AWT Team.

Please review the fix for the issue:
https://bugs.openjdk.java.net/browse/JDK-8026262
The fix is available at:
http://cr.openjdk.java.net/~pchelko/8026262/webrev.00/

The cause is a forgotten null check in the JDK-8024987 fix. When we try to find all known natives for a type the flavour-to-native cache could not contain some data flavours yet, 
so we are getting a null as a list of corresponding mime-types. It's a valid situation, so a simple null check fixes the problem. The cache will be updated later when the getNativesForFlavour
method will finish.

The fix was tested with the case described in a netbeans bug: without the fix I fail to DnD a file from Krusader file manager, with a fix I can drag it successfully.

With best regards. Petr.