bug#34489: 25.2; pdb fails if directory contains '++'

[a.soroa]

'pdb' command does not work if the directory where the python script is
contains the characters '++'. Here is a receipt

$ mkdir /tmp/foo++
$ cd /tmp/foo++
$ echo "print(10)" > pp.py
$ emacs -Q
M-x pdb
Run pdb (like this): python3 -m pdb pp.py




In GNU Emacs 25.2.2 (x86_64-pc-linux-gnu, GTK+ Version 3.22.21)
 of 2017-09-22, modified by Debian built on lgw01-amd64-050
Windowing system distributor 'The X.Org Foundation', version 11.0.11906000
System Description:     Ubuntu 18.04.2 LTS

Configured using:
 'configure --build x86_64-linux-gnu --prefix=/usr
 --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --with-pop=yes
 
--enable-locallisppath=/etc/emacs25:/etc/emacs:/usr/local/share/emacs/25.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/25.2/site-lisp:/usr/share/emacs/site-lisp
 --with-sound=alsa --without-gconf --build x86_64-linux-gnu
 --prefix=/usr --sharedstatedir=/var/lib --libexecdir=/usr/lib
 --localstatedir=/var/lib --infodir=/usr/share/info
 --mandir=/usr/share/man --with-pop=yes
 
--enable-locallisppath=/etc/emacs25:/etc/emacs:/usr/local/share/emacs/25.2/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/25.2/site-lisp:/usr/share/emacs/site-lisp
 --with-sound=alsa --without-gconf --with-x=yes --with-x-toolkit=gtk3
 --with-toolkit-scroll-bars 'CFLAGS=-g -O2
 -fdebug-prefix-map=/build/emacs25-jYekUr/emacs25-25.2+1=. 
-fstack-protector-strong
 -Wformat -Werror=format-security -Wall' 'CPPFLAGS=-Wdate-time
 -D_FORTIFY_SOURCE=2' 'LDFLAGS=-Wl,-Bsymbolic-functions -Wl,-z,relro''

Configured features:
XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS NOTIFY
ACL LIBSELINUX GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB
TOOLKIT_SCROLL_BARS GTK3 X11

Important settings:
  value of $LC_MONETARY: en_IE.UTF-8
  value of $LC_NUMERIC: en_IE.UTF-8
  value of $LC_TIME: en_IE.UTF-8
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8-unix

Major mode: Shell

Minor modes in effect:
  shell-dirtrack-mode: t
  global-flycheck-mode: t
  diff-auto-refine-mode: t
  global-company-mode: t
  company-mode: t
  projectile-mode: t
  ido-vertical-mode: t
  save-place-mode: t
  override-global-mode: t
  tooltip-mode: t
  global-eldoc-mode: t
  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
  blink-cursor-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
libreoffice 2019-1-9-DK-Sailak-IIG-Bilera-\(Pepe\).odt: finished.
~ 
/tmp 
/tmp/k++ 
(New file)
Can’t guess python-indent-offset, using defaults: 4
Trailing newlines [trailing-newlines]
next-line: End of buffer
Saving file /tmp/k++/pp.py...
Wrote /tmp/k++/pp.py
Quit

Load-path shadows:
/usr/share/emacs/25.2/site-lisp/debian-startup hides 
/usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs/site-lisp/rst hides /usr/share/emacs/25.2/lisp/textmodes/rst
/home/ccpsoeta/.emacs.d/elpa/let-alist-1.0.5/let-alist hides 
/usr/share/emacs/25.2/lisp/emacs-lisp/let-alist

Features:
(shadow sort mail-extr emacsbug gud pcmpl-unix conf-mode network-stream
nsm starttls url-cache url-http tls gnutls url-gw url-auth warnings
vc-git company-jedi jedi-core python-environment epc ctable concurrent
python tramp-sh misearch multi-isearch cal-move parse-time mm-archive
shr-color color shr dom browse-url notmuch hl-line notmuch-message
notmuch-hello notmuch-tree notmuch-show notmuch-print notmuch-crypto
notmuch-mua notmuch-draft notmuch-maildir-fcc notmuch-address
notmuch-company notmuch-parser notmuch-wash coolj notmuch-query
goto-addr icalendar diary-lib diary-loaddefs notmuch-tag crm notmuch-lib
notmuch-compat cl mm-view mml-smime smime dig org-agenda flyspell rect
tramp-cache tramp tramp-compat tramp-loaddefs trampver ucs-normalize
shell org-element org-rmail org-mhe org-irc org-info org-gnus
org-docview doc-view jka-compr image-mode org-bibtex bibtex org-bbdb
org-w3m org org-macro org-footnote org-pcomplete pcomplete org-list
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ob-tangle ob-ref ob-lob ob-table ob-exp org-src ob-keys ob-comint
ob-core ob-eval org-compat org-macs org-loaddefs cal-menu calendar
cal-loaddefs windmove dired-aux message sendmail format-spec rfc822 mml
mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045
ietf-drums mailabbrev gmm-utils mailheader ispell flycheck find-func
company-ycmd f ycmd diff-mode diff request-deferred request mail-utils
url url-proxy url-privacy url-expand url-methods url-history url-cookie
url-domsuf url-util url-parse auth-source gnus-util mm-util help-fns
mail-prsvr password-cache url-vars mailcap json map hmac-def deferred s
dash cus-edit wid-edit company-oddmuse company-keywords company-etags
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company-clang company-semantic company-eclim company-template
company-css company-nxml company-bbdb company projectile subr-x grep
compile comint ansi-color ring ibuf-ext ibuffer thingatpt flx-ido advice
flx ido-vertical-mode ido cus-start cus-load dired-x dired printing
ps-print ps-def lpr server pinentry epa derived epg saveplace cl-macs
cl-seq use-package use-package-ensure use-package-delight
use-package-diminish use-package-bind-key bind-key easy-mmode
use-package-core edmacro kmacro finder-inf tex-site rx info package
epg-config seq byte-opt gv bytecomp byte-compile cl-extra help-mode
easymenu cconv cl-loaddefs pcase cl-lib time-date mule-util tooltip
eldoc electric uniquify ediff-hook vc-hooks lisp-float-type mwheel x-win
term/common-win x-dnd tool-bar dnd fontset image regexp-opt fringe
tabulated-list newcomment elisp-mode lisp-mode prog-mode register page
menu-bar rfn-eshadow timer select scroll-bar mouse jit-lock font-lock
syntax facemenu font-core frame cl-generic cham georgian utf-8-lang
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cp51932 hebrew greek romanian slovak czech european ethiopic indian
cyrillic chinese charscript case-table epa-hook jka-cmpr-hook help
simple abbrev minibuffer cl-preloaded 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
dbusbind inotify dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty make-network-process emacs)

Memory information:
((conses 16 684834 57692)
 (symbols 48 49680 0)
 (miscs 40 2836 1964)
 (strings 32 162971 25757)
 (string-bytes 1 4632525)
 (vectors 16 77915)
 (vector-slots 8 1988582 65164)
 (floats 8 910 634)
 (intervals 56 11276 252)
 (buffers 976 73))