516394 - Regression caused by changed value of JSVAL_VOID constant.

Status: RESOLVED WONTFIX

(Core :: JavaScript Engine, defect)

Description

[Alexander Mitin]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; ru; rv:1.9.0.14) Gecko/2009090216 Ubuntu/9.04 (jaunty) Firefox/3.0.14
Build Identifier: xulrunner-1.9.1.2

The mozilla-embedding app which works with JS stops working while running against xulrunner-1.9.1.x
This app was compiled against xulrunner-sdk-1.9.0.x and contains older value of JSVAL_VOID compiled in. So, since in 1.9.1.x the JSVAL_VOID has another value, the app is not working because 0x80000001 != 0x16 ;)

See this 'enhancement' https://bugzilla.mozilla.org/show_bug.cgi?id=432881 for problem history.

Reproducible: Always

Steps to Reproduce:
1. Create mozilla-embedding app which operates with it's own JS classes inside of the standard DOM, ex., define your own (custom-class-type) property in 'window' object. Use checking against JSVAL_VOID for something.
2. Compile it against 1.9.0.x, make it working. :)
3. Run the app against 1.9.1.x

Comment 1

[Brendan Eich [:brendan]]

We don't do binary compatibility across non-patch releases.

See http://www.aaronboodman.com/2009/07/bundling-multiple-versions-of-binary.html for a technique that may help ease the pain.

/be

Comment 2

[Brendan Eich [:brendan]]

Another way to go is ask the engine for its idea of JSVAL_VOID, by looking up "undefined" in a virgin global object, and use that. Less efficient but smaller code footprint duplication hit.

/be