bug#22731: emacs-25: Double clicks don't get through to C-h c.

[Alan Mackenzie]

Hello, Emacs.

In the emacs-25 branch, start Emacs with emacs -Q.

In the *scratch* buffer, do C-h c followed by a double click on the left
mouse button.

Examine the *Messages* buffer.  There it will be reported that
"<down-mouse-1> at that spot runs the command mouse-drag-region".  This
is wrong - the event handling code has got impatient and returned the
info for <down-mouse-1> rather than waiting for the actual complete
event which is a double click.

However, a double click in the *scratch* buffer without C-h c is read
correctly, marking the word under the mouse.  It would be nice to be
able to find out what this command is that does the marking.

-- 
Alan Mackenzie (Nuremberg, Germany).