bug#43139: 24.5; Strange gdb behavior

bug#43139: 24.5; Strange gdb behavior

[Onyebuchi Ekenta]

I've been using gdb in emacs for a bit now and I mostly love it, but
there are some minor quirks about its behavior that I find bothersome
and I wanted to know how to go about tweaking them. I also want to say I
know almost nothing about modifying emacs in general.

I've been using gdb-many-windows when I debug. The thing I want to
change is the behavior around breakpoints. After a breakpoint is hit,
the source window moves to the line I placed the breakpoint on. This is
good, I like that. But after that, if I move to a different part of the
source file myself and then run any gdb command, the source window will
automatically move back to the line containing the breakpoint. So if I
want to, say, set a breakpoint at a different line of the source file,
the moment I do so the source window snaps back to the first
breakpoint. This has me constantly moving up and down the source file.

To be specific, I'm debugging the MATLAB library LUSOL, found at
https://github.com/nwh/lusol/ . I modified the makefile to add the
debug (-g) flag to the fortran compiler so I could step through the
source. 



====================================






In GNU Emacs 24.5.1 (x86_64-pc-linux-gnu, GTK+ Version 3.22.11)
 of 2017-09-12 on hullmann, modified by Debian
System Description:	Debian GNU/Linux 9.13 (stretch)

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/emacs24:/etc/emacs:/usr/local/share/emacs/24.5/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.5/site-lisp:/usr/share/emacs/site-lisp
 --without-gnutls --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/emacs24:/etc/emacs:/usr/local/share/emacs/24.5/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/24.5/site-lisp:/usr/share/emacs/site-lisp
 --without-gnutls --with-x=yes --with-x-toolkit=gtk3
 --with-toolkit-scroll-bars 'CFLAGS=-g -O2
 -fdebug-prefix-map=/build/emacs24-24.5+1=. -fstack-protector-strong
 -Wformat -Werror=format-security -Wall -fno-PIE' 'CPPFLAGS=-Wdate-time
 -D_FORTIFY_SOURCE=2' 'LDFLAGS=-Wl,-z,relro -no-pie''

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

Major mode: Fundamental

Minor modes in effect:
  tooltip-mode: t
  electric-indent-mode: t
  mouse-wheel-mode: t
  tool-bar-mode: t
  menu-bar-mode: t
  file-name-shadow-mode: t
  global-font-lock-mode: t
  auto-composition-mode: t
  auto-encryption-mode: t
  auto-compression-mode: t
  buffer-read-only: t
  line-number-mode: t
  transient-mark-mode: t

Recent messages:
Loading /etc/emacs/site-start.d/50cmake-data.el (source)...done
Loading /etc/emacs/site-start.d/50dictionaries-common.el (source)...
Loading debian-ispell...
Loading /var/cache/dictionaries-common/emacsen-ispell-default.el (source)...done
Loading debian-ispell...done
Loading /var/cache/dictionaries-common/emacsen-ispell-dicts.el (source)...done
Loading /etc/emacs/site-start.d/50dictionaries-common.el (source)...done
Loading /etc/emacs/site-start.d/50python-docutils.el (source)...done
Loading /etc/emacs/site-start.d/50tcsh.el (source)...done
For information about GNU Emacs and the GNU system, type C-h C-a.

Load-path shadows:
/usr/share/emacs/24.5/site-lisp/debian-startup hides /usr/share/emacs/site-lisp/debian-startup
/usr/share/emacs24/site-lisp/cmake-data/cmake-mode hides /usr/share/emacs/site-lisp/cmake-mode
/usr/share/emacs/site-lisp/rst hides /usr/share/emacs/24.5/lisp/textmodes/rst

Features:
(shadow sort gnus-util mail-extr emacsbug message format-spec rfc822 mml
easymenu mml-sec mm-decode mm-bodies mm-encode mail-parse rfc2231
mailabbrev gmm-utils mailheader sendmail rfc2047 rfc2045 ietf-drums
mm-util help-fns mail-prsvr mail-utils xterm time-date manoj-dark-theme
edmacro kmacro cl-loaddefs cl-lib tooltip electric uniquify ediff-hook
vc-hooks lisp-float-type mwheel x-win x-dnd 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 dbusbind
gfilenotify dynamic-setting system-font-setting font-render-setting
move-toolbar gtk x-toolkit x multi-tty emacs)

Memory information:
((conses 16 87423 8190)
 (symbols 48 18593 0)
 (miscs 40 70 99)
 (strings 32 11562 4713)
 (string-bytes 1 318162)
 (vectors 16 7591)
 (vector-slots 8 345006 30036)
 (floats 8 82 333)
 (intervals 56 220 0)
 (buffers 960 12))