bug#8947: 24.0.50; `describe-mode': `help-mode-map' pollutes minor mode descriptions

[Drew Adams]

This bug seems to date from the first day that `describe-mode' included
minor-mode information.
 
emacs -Q
 
Visit any *.el file, hit `C-h m', then search for `Transient' in *Help*.
The help for `transient-mark-mode' says this:
 
"...for example, incremental search, <, and >."
 
`<' and `>' here should be `M-<' and `M->'.  The bug happens because
`help-mode-map' is being used to interpret `\\[beginning-of-buffer]'
and `\\[end-of-buffer]'.  In the *Help* buffer, where the text is
used, the current keymap is being picked up, where these commands
are bound to `<' and `>'.
 
Note that the problem isn't manifested for something like `C-h f
transient-mark-mode'.  In that case the bindings picked up are those of
the current buffer where the command is issued.  If you do that in
*Help* then you get `<' and `>'.  If you do it in *.el then you get
`M-<' and `M->'.
 
In GNU Emacs 24.0.50.1 (i386-mingw-nt5.1.2600)
 of 2011-06-27 on 3249CTO
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (4.5) --no-opt --cflags
-Ic:/build/include'