toUpperCase in JavaScript yields wrong results

Short summary: toUpperCase in JavaScriptCore in QtWebKit yields wrong results with numeric values in the string. This is a regression between the 5.1.0 Beta and the RC1. toUpperCase is used in a lot of frameworks like jQuery etc., so this is a blocking issue imho.

Detailed description from a mail from Eike Rethmeier on the qtwebkit mailing list:

I found an JavaScript bug in the toUpperCase() function in Qt5.1 Release Candidate. That bug was not in Qt5.1 Beta.

That’s how it should behave (call and result), tested with Qt5.1 Beta and former versions (and Chrome and Firefox)
"Hello123 World!".toUpperCase()
"HELLO123 WORLD!"

That’s how it behaves with Qt5.1 Release Candidate in Win7 (VS2012 build):
"Hello123 World!".toUpperCase()
"HELLOWORLD"

Funny thing is, I do not visually see these strange characters betwenn HELLO and WORLD in the inspector, I only see them when I copy the string from the inspector and paste them into this Email. In the inspector it looks like 4 spaces between HELLO and WORLD. In WinXP it looks like this in the inspector:

Qt5.1 Release Candidate in WinXP (VS2012 build):
"Hello123 World!".toUpperCase()
"HELLOWORLD "