[icedtea-web] Regression after refactoring for XDG specification

[Jacob Wisor]

Hello,

I get the following regression since the code has been refactored to conform to the XDG specification, at least on Windows, but it should apply to Un*x systems too.

Exception occurred during event dispatching:
java.lang.NullPointerException
        at net.sourceforge.jnlp.cache.CacheDirectory.getDirStructure(CacheDirect
ory.java:56)
        at net.sourceforge.jnlp.controlpanel.CachePane.generateData(CachePane.ja
va:360)
        at net.sourceforge.jnlp.controlpanel.CachePane.populateTable(CachePane.j
ava:343)
        at net.sourceforge.jnlp.controlpanel.CachePane.access$500(CachePane.java
:66)
        at net.sourceforge.jnlp.controlpanel.CachePane$8.run(CachePane.java:312)

        at java.awt.event.InvocationEvent.dispatch(Unknown Source)
        at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
        at java.awt.EventQueue.access$400(Unknown Source)
        at java.awt.EventQueue$2.run(Unknown Source)
        at java.awt.EventQueue$2.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.Dialog$1.run(Unknown Source)
        at java.awt.Dialog$3.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.awt.Dialog.show(Unknown Source)
        at java.awt.Component.show(Unknown Source)
        at java.awt.Component.setVisible(Unknown Source)
        at java.awt.Window.setVisible(Unknown Source)
        at java.awt.Dialog.setVisible(Unknown Source)
        at net.sourceforge.jnlp.controlpanel.CacheViewer.showCacheDialog(CacheVi
ewer.java:149)
        at net.sourceforge.jnlp.controlpanel.TemporaryInternetFilesPanel$4.actio
nPerformed(TemporaryInternetFilesPanel.java:206)
        at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)
        at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)
        at javax.swing.DefaultButtonModel.setPressed(Unknown Source)
        at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Sour
ce)
        at java.awt.Component.processMouseEvent(Unknown Source)
        at javax.swing.JComponent.processMouseEvent(Unknown Source)
        at java.awt.Component.processEvent(Unknown Source)
        at java.awt.Container.processEvent(Unknown Source)
        at java.awt.Component.dispatchEventImpl(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
        at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
        at java.awt.Container.dispatchEventImpl(Unknown Source)
        at java.awt.Window.dispatchEventImpl(Unknown Source)
        at java.awt.Component.dispatchEvent(Unknown Source)
        at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
        at java.awt.EventQueue.access$400(Unknown Source)
        at java.awt.EventQueue$2.run(Unknown Source)
        at java.awt.EventQueue$2.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.awt.EventQueue$3.run(Unknown Source)
        at java.awt.EventQueue$3.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown
Source)
        at java.awt.EventQueue.dispatchEvent(Unknown Source)
        at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
        at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
        at java.awt.EventDispatchThread.run(Unknown Source)

The cause of this NullPointerException is a missing %USERPROFILE%\.cache\icedtea-web\cache or ~/.cache/icedtea-web/cache folder. There should be check for existance before trying to list files in this folder, if non-existent it should be created. Btw. since net.sourceforge.jnlp.cache.CacheDirectory.getDirStructure(DirectoryNode) is public, it should check the root parameter for null.
I would have fixed this myself, but because I have not refactored the code to conform to the XDG specification, I did not want to touch it, while not knowing what to possibly touch as well and hence add perhaps even more damage.

To reproduce: Delete %USERPROFILE%\.cache\icedtea-web\cache or ~/.cache/icedtea-web/cache and then open the cache viewer (perhaps refresh).

Regards,
Jacob