495785 - Rhino interpreter shell crashes with NullPointerException

Status: RESOLVED FIXED

(Rhino Graveyard :: Core, defect)

Description

[Toshio Kuratomi]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b4) Gecko/20090427 Fedora/3.5-0.20.beta4.fc11 Firefox/3.5b4
Build Identifier: Rhino-1.7r2

On Fedora Linux with rhino-1.7r2, scripts can run but trying to run the interactive shell throws a NullPointerException.  The cause is diagnosed in this bug in the Fedora bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=457336


Reproducible: Always

Steps to Reproduce:
1. $ java org.mozilla.javascript.tools.shell.Main
2.
3.
Actual Results:  
Rhino 1.7 release 0.5.r2.fc10 2009 04 23
Exception in thread "main" java.lang.NullPointerException
 at org.mozilla.javascript.Kit.classOrNull(Kit.java:92)
 at org.mozilla.javascript.tools.shell.ShellLine.getStream(ShellLine.java:65)
 at org.mozilla.javascript.tools.shell.Global.getIn(Global.java:829)
 at org.mozilla.javascript.tools.shell.Main.processSource(Main.java:385)
 at org.mozilla.javascript.tools.shell.Main.processFiles(Main.java:196)
 at org.mozilla.javascript.tools.shell.Main$IProxy.run(Main.java:117)
 at org.mozilla.javascript.Context.call(Context.java:515)
 at org.mozilla.javascript.ContextFactory.call(ContextFactory.java:507)
 at org.mozilla.javascript.tools.shell.Main.exec(Main.java:179)
 at org.mozilla.javascript.tools.shell.Main.main(Main.java:157)



Expected Results:  
Rhino 1.7 release 0.6.r2.fc11 2009 05 31
js>


Steven Elliot diagnosed the bug in the Fedora bug tracker and came up with the following:

"""
I've looked into the null pointer exception quoted above. I believe it's a
result of Rhino attempting to dynamically load the jline library.  My
understanding is that there are both class specific class loaders and a generic
system class loader.  With this fix both will be attempted, if necessary, to
dynamically load a jline class.
"""

I'll attach his patch (which fixes the exception).

Comment 1

[Toshio Kuratomi]

Attachment: Patch to fallback to system jline if class specific loader fails

Steven Elliott's patch to try the class specific loader for jline, then the system loader, then return null if no jline was found.

Comment 2

[Toshio Kuratomi]

Attachment: Same patch minus Fedora script changes

Here's the same patch minus changes to a Fedora-local script to invoke rhino with jline support.

Comment 3

[Norris Boyd]

Fixed in CVS:

Checking in toolsrc/org/mozilla/javascript/tools/shell/ShellLine.java;
/cvsroot/mozilla/js/rhino/toolsrc/org/mozilla/javascript/tools/shell/ShellLine.java,v  <--  ShellLine.java
new revision: 1.5; previous revision: 1.4
done

Thanks!