Edited on 9 June 2009 Mozilla guys decided to add a getter for imageURL so no extension will be affected by new property mediaURL replacement, you can read the full story at bug 497098.
Another time Mozilla community demonstrates its strength, why nobody considered the impact before modification is another story 😉
Today a ViewSourceWith user filed a bug about a regression on Firefox 3.5b4, causing VSW to no more open images 😯
After dressing the debug uniform I started to investigate the problem.
I’ve realized the object gContextMenu doesn’t more contain the property imageURL used by VSW and maybe many other extensions.
The imageURL property has been renamed/refactored to mediaURL.
Honestly the new name fits better its new usage and maybe the imageURL property is not intended for usage from extensions.
The poor gContextMenu documentation doesn’t describe imageURL so maybe I abused its usage.
I think gContextMenu need a better documentation because its usage is so sexy inside extensions.
A string find/replace inside code fixed the bug, to maintain compatibility with FF 3.0.x I’ve modified the code as shown below
var imageURL = gContextMenu.imageURL || gContextMenu.mediaURL;