FULL PRODUCT VERSION :
1.7.0_55

ADDITIONAL OS VERSION INFORMATION :
Windows 8

EXTRA RELEVANT SYSTEM CONFIGURATION :
Same with Chrome and Firefox (and likely IE)

A DESCRIPTION OF THE PROBLEM :
You can see with your own URL. This fails:

http://docs.oracle.com/javase/tutorial/deployment/webstart/examples/dist/webstart_ComponentArch_DynamicTreeDemo/JavaWebStartAppPage_No_Codebase.html?this=is%20a%20test

This works:

http://docs.oracle.com/javase/tutorial/deployment/webstart/examples/dist/webstart_ComponentArch_DynamicTreeDemo/JavaWebStartAppPage_No_Codebase.html?this=is_a_test

The failures occur when the percent sign is in the URL of the launching page _OR_ the JNLP file. It appears your code is using the same validation function for both. In my case I can have percent signs in both.

I've attemped with both the "launchApp" function in the plugin, and also with the "launchjnlp" attribute on the embed tag.

I'd appreciate a work-around if one is available. I'm now exploring some of the parameters for the launchApp function.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Go to the URL and click the button to launch the app.

This fails:

http://docs.oracle.com/javase/tutorial/deployment/webstart/examples/dist/webstart_ComponentArch_DynamicTreeDemo/JavaWebStartAppPage_No_Codebase.html?this=is%20a%20test

This works:

http://docs.oracle.com/javase/tutorial/deployment/webstart/examples/dist/webstart_ComponentArch_DynamicTreeDemo/JavaWebStartAppPage_No_Codebase.html?this=is_a_test


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
The web start app should launch.
ACTUAL -
It does not launch.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Calling the 'launchApp' function fails.

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
I'd love one.