bug#19966: 24.4; Get error on hover over variable for tooltip inspection, gud/pdb

[Tom Burbage <tiburbage@gmail.com>]

Using current binary build of Emacs 24.4 for Windows.
emacs-24.4-bin-i686-pc-mingw32
The use context is:
1 - Open a python source file
2 - M-x pdb  ;; run gud/pdb for the current .py
3 - step until a variable becomes defined/initialized
4 - hover the mouse over the variable name in the source
The errors:
Error running timer `tooltip-timeout': (wrong-type-argument markerp nil)
Command: next [4 times]
Error running timer `tooltip-timeout': (void-variable v) [2 times]

NOTES
- I have the tooltip.el tooltip-mode OFF/nil
- I have gud-tooltip-mode ON (obviously)
- If I start Emacs w/ --no-init, I can still reproduce the problem
- If I replace progmodes/gud.el , gud.elc with those from 24.3, the
errors do not occur

Other problems ensue on Windows when tooltip messages actually display
as tooltip windows, and I suspect maybe it is an HWND stealing problem,
but not sure and that's a different issue. I'm OK with the info being
printed to the "echo area"







In GNU Emacs 24.4.1 (i686-pc-mingw32)
  of 2014-10-24 on LEG570
Windowing system distributor `Microsoft Corp.', version 6.3.9600
Configured using:
  `configure --prefix=/c/usr'

Important settings:
   value of $LANG: ENU
   locale-coding-system: cp1252

Major mode: Messages

Minor modes in effect:
   gud-tooltip-mode: t
   pyvenv-mode: t
   minibuffer-electric-default-mode: t
   delete-selection-mode: t
   show-paren-mode: t
   global-auto-revert-mode: t
   yas-global-mode: 0
   electric-indent-mode: t
   mouse-wheel-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   buffer-read-only: t
   column-number-mode: t
   line-number-mode: t
   transient-mark-mode: t

Recent input:
<help-echo> C-x C-f d : / s r c / e x m <backspace>
a m <return> p y <return> b i t w <return> M-x p d
b <return> <return> <mouse-movement> C-c C-n C-c C-n
C-c C-n C-c C-n <mouse-movement> <mouse-movement> <help-echo>
<mouse-movement> <mouse-movement> <C-down-mouse-1>
<down-mouse-1> <mouse-movement> <mouse-movement> <drag-mouse-1>
M-w <down-mouse-1> <mouse-movement> <mouse-movement>
<drag-mouse-1> M-w <help-echo> <down-mouse-1> <mouse-1>
M-x r e p o r t - e m a c s - b u g <return>

Recent messages:
[yas] Loading for `fundamental-mode', just-in-time: (lambda nil 
(yas--load-directory-1 (quote 
c:/Users/tiburbage/.emacs.d/elpa/yasnippet-20150212.240/snippets/fundamental-mode) 
(quote fundamental-mode)))!
[yas] Loading compiled snippets from 
c:/Users/tiburbage/.emacs.d/elpa/yasnippet-20150212.240/snippets/fundamental-mode
Loading 
c:/Users/tiburbage/.emacs.d/elpa/yasnippet-20150212.240/snippets/fundamental-mode/.yas-setup...done
[yas] Prepared just-in-time loading for 
c:/Users/tiburbage/.emacs.d/elpa/yasnippet-20150212.240/snippets
[yas] Prepared just-in-time loading for ~/.emacs.d/snippets
[yas] Reloaded everything (snippets will load just-in-time)....
ad-handle-definition: `pdb' got redefined
Error running timer `tooltip-timeout': (wrong-type-argument markerp nil)
Command: next [4 times]
Error running timer `tooltip-timeout': (void-variable v) [2 times]

Load-path shadows:
None found.

Features:
(shadow sort gnus-util mail-extr warnings emacsbug message rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 mailabbrev
gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils gud company-files company-oddmuse company-keywords
company-etags company-gtags company-dabbrev-code company-dabbrev
company-cmake company-xcode company-clang company-eclim company-template
company-css company-nxml company-bbdb highlight-indentation flymake
company edmacro kmacro elpy pyvenv elpy-refactor grep compile files-x
etags cus-edit cus-start cus-load wid-edit python json eldoc
ecb-autoloads org-mouse org-info cl-macs cc-styles cc-align cc-engine
cc-vars cc-defs org org-macro org-footnote org-pcomplete pcomplete
org-list org-faces org-entities noutline outline org-version
ob-emacs-lisp ob ob-tangle ob-ref ob-lob ob-table ob-exp org-src ob-keys
ob-comint comint ansi-color ring ob-core ob-eval org-compat org-macs
org-loaddefs find-func cal-menu calendar cal-loaddefs ido minibuf-eldef
delsel paren autorevert filenotify yasnippet cl gv help-mode easy-mmode
advice help-fns dired+ image-dired cl-loaddefs cl-lib format-spec
image-file dired-aux w32-browser dired-x dired tib_dark_base-theme eieio
byte-opt bytecomp byte-compile cconv eieio-core info easymenu
pyflakes-autoloads pymacs-autoloads python-pep8-autoloads package
epg-config time-date tooltip electric uniquify ediff-hook vc-hooks
lisp-float-type mwheel dos-w32 ls-lisp w32-common-fns disp-table w32-win
w32-vars tool-bar dnd fontset image regexp-opt fringe tabulated-list
newcomment lisp-mode prog-mode register page menu-bar rfn-eshadow timer
select scroll-bar mouse jit-lock font-lock syntax facemenu font-core
frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai
tai-viet lao korean japanese hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help
simple abbrev minibuffer nadvice loaddefs button faces cus-face macroexp
files text-properties overlay sha1 md5 base64 format env code-pages mule
custom widget hashtable-print-readable backquote make-network-process
w32notify w32 multi-tty emacs)

Memory information:
((conses 8 272601 22701)
  (symbols 32 36073 0)
  (miscs 32 116 303)
  (strings 16 76881 9492)
  (string-bytes 1 2192836)
  (vectors 8 30374)
  (vector-slots 4 702227 6942)
  (floats 8 776 381)
  (intervals 28 410 2)
  (buffers 508 15))