bug#19918: 25.0.50; links in *Backtrace* & *Help* go to the wrong function definitions

[Drew Adams <drew.adams@oracle.com>]

In my setup, i.e., with Bookmark+ loaded, function `bookmark-bmenu-list'
is defined in file bookmark+-bmu.el.  In the debugger, there is a line
like this:

 * bookmark-bmenu-list(nil)

with the function name highlighted with a button.  `C-u C-x =' on the
name shows this:

 Here is a `help-function-def' button labeled `bookmark-bmenu-list'.


 There are text properties here:
   button               (t)
   category             help-function-def-button
   help-args            [Show]

Clicking [Show] shows this:

 (bookmark-bmenu-list
   "d:/Emacs-25-2014-10-20/share/emacs/25.0.50/lisp/bookmark.el")

That's wrong.  And clicking mouse-2 on that button takes me to that
wrong file.  And so does `C-h f' followed by the name and clicking on
the library, which is shown as bookmark.el.

The debugger correctly traverses the code of the version of the function
that is defined in bookmark+-bmu.el, however.

IOW, the function is defined correctly.  It is only the links in Help
and the debugger that are wrong, as well as the file name in Help.  But
the doc string in Help is correct - it is the doc string for the
Bookmark+ version of the function.

The redefinition of the function in bookmark+-bmu.el is a
straightforward defun.


In GNU Emacs 25.0.50.1 (i686-pc-mingw32)
 of 2014-10-20 on LEG570
Bzr revision: 118168 rgm@gnu.org-20141020195941-icp42t8ttcnud09g
Windowing system distributor `Microsoft Corp.', version 6.1.7601
Configured using:
 `configure --enable-checking=yes,glyphs CPPFLAGS=-DGLYPH_DEBUG=1'