I don't know how the help browser works (Hans-Christophe wrote it) and don't know whether that comment character is in there for some reason or not. So I'm scared to fix this without hearing from HC.
I wonder if the old-fashioned idea of just using the file browser should be available as at least an option...
The preceding 'if' statement applies that part of the code only if you have Tcl/Tk >= 8.5. Hence it will be a non-issue for most current users who might be relying upon the 8.4 version of the toolkit. I am currently using 8.5 and I can tell you that before this fix every time I wanted to go up one level by clicking onto a column which is followed by an existing child column (obviously one which I was browsing prior to requesting going up on level), the browser fails reporting error that the new listview1 of the newly requested folder cannot be created as one already exists (since 8.4 code below destroys children views but 8.5 does nothing, hence the error). So, this code in effect destroys sub-folder views in order to recreate new one only under 8.5. The only way to circumvent this problem without this fix is to close the help browser and open a new one which is a total pain as your path restarts in the root doc folder. Removing this comment simply makes it possible to do browsing the same like you would do with Tcl/Tk 8.4. FWIW, I now use this fix on a daily basis and I am yet to experience any side-effects.
For this reason, I think this is a fix that is critical for Tcl/Tk >=8.5 users, while others will never see any difference.
Best wishes,
Ico