On February 13th, 2014, 3:32 p.m. UTC, Kurt Hindenburg wrote:

Thanks for the patch; however, I don't think this is worth adding.  The user can right-click->close tab.

Please refer to Bug 191751 https://bugs.kde.org/show_bug.cgi?id=191751  for the full discussion that lead to this patch, the option is disabled by default and it is there for the users who want to have this feature

- Helmy

On March 18th, 2013, 9:34 p.m. UTC, Oleksandr Sochka wrote:

There is no action assigned on middle mouse button right now
and this patch adds an option to Settings->Configure->Taskbar which enables 
closing a tab like in browsers/different editors using wheel click.

Option is disabled by default.

Tested manually