533835 - Config parameter mail.showFolderPaneColumns apparently broken on Mac; no way to select columns Unread, Total, Size.

Status: RESOLVED DUPLICATE of bug 464973

(Thunderbird :: Mail Window Front End, defect)

Description

[eric raeburn]

User-Agent:       Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_2; en-us) AppleWebKit/531.21.8 (KHTML, like Gecko) Version/4.0.4 Safari/531.21.10
Build Identifier: Thunderbird 3.0 (20090812), MAC OSX 10.6.2

I have just updated from Tbird 2.0.0.23 to 3.0 on a new MacBook Pro (latest OS X as of this date).  The folder pane columns are gone, and there's no symbol to click to make them appear.  I've looked in the advanced config and in prefs.js; in both places the config parameter mail.showFolderPaneColumns is set to "True".  I tried setting to "False" and restarting, setting it back, etc., but the columns do not appear, nor does the little symbol that allows the user to select which columns to display.  Does this depend on the parameter mail.ui.folderpane.version?  How is that parameter used?  It is an integer, set to its default value of 1. kb.mozillazine.org states this parameter is a boolean; that is apparently incorrect.

Reproducible: Always

Steps to Reproduce:
1. Install Thunderbird 3.0 on Mac OS X.
2. In advanced config, set mail.showFolderPaneColumns to True.
3. Even with that setting, no folder pane columns appear, and there is no symbol to click to select such columns.
Actual Results:  
No folder pane columns appear, and there is no symbol to click to select such columns.

Expected Results:  
As in previous versions of Thunderbird, a column header with the default "Name" should have appeared, along with a clickable symbol to allow the user to select which columns should appear (Unread, Total, Size).

I have left the Severity at "normal" for this problem, but for users who depend on this functionality, the fact that it is apparently broken is rather annoying.