[GRASS-dev] Re: [GRASS GIS] #693: wxGUI menus: i.ortho.photo locks up GUI

[GRASS GIS]

#693: wxGUI menus: i.ortho.photo locks up GUI
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  Reporter:  hamish  |       Owner:  grass-dev at lists.osgeo.org
      Type:  defect  |      Status:  new                      
  Priority:  major   |   Milestone:  6.4.0                    
 Component:  wxGUI   |     Version:  svn-develbranch6         
Resolution:          |    Keywords:  i.ortho.photo            
  Platform:  All     |         Cpu:  x86-64                   
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Comment (by glynn):

 Replying to [comment:7 cmbarton]:

 > But it might be better if there is an environmental variable GRASS_XTERM
 that is set to a platform specific value than a script that tries to
 figure it out.

 There is such a variable; that's the whole point of grass-xterm-wrapper.
 It is essentially just:
 {{{
 exec "$GRASS_XTERM" "$@"
 }}}
 except that it also tries to autodetect a suitable program if GRASS_XTERM
 isn't set.

 However, wxGUI's GMFrame.OnXTerm() method involves rather more than simply
 running a command in a terminal.

 First, it invokes the command via grass-run.{sh,bat}. The primary
 rationale for that script is to restore LD_LIBRARY_PATH in case the loader
 resets it due to xterm being setuid/setgid. But in typical form, the
 grass-run.sh script has been "enhanced" with other functionality. The
 grass-run.src file '''should''' be nothing more than:
 {{{
 LD_LIBRARY_PATH_VAR=$GRASS_LD_LIBRARY_PATH
 export LD_LIBRARY_PATH_VAR
 exec "$@"
 }}}
 Everything else is gratuitous, and possibly harmful.

 Second, GMFrame.OnXTerm() starts (and selects) another XDRIVER monitor (I
 don't see where (or even if) it stops this monitor, and I'm fairly sure
 that it doesn't re-select the previous monitor).

 Ah. This is where it goes beserk. It constructs the command as:
 {{{
 command = shlex.split(str(command))
 ...
 cmdlist = [xtermwrapper, '-e "%s"' % grassrun, command]
 }}}
 which will result in cmdlist looking something like:
 {{{
 ['/usr/local/src/grass/svn/dist.i686-pc-linux-gnu/etc/grass-xterm-
 wrapper',
 '-e "/usr/local/src/grass/svn/dist.i686-pc-linux-gnu/etc/grass-
 run.sh"',['i.ortho.photo']]
 }}}
 How many things are wrong with this? Apart from the last argument being a
 Python list (which gcmd.Command() '''might''' handle), the -e switch is
 merged into the same argument as its value. And its value is quoted,
 whereas xterm's -e switch signifies that all remaining arguments are to be
 treated as the command and its arguments (unlike e.g. /bin/sh's -c switch,
 which expects a single argument).

 Does GMFrame.OnXTerm() work at all for anything on any platform? I'm hard
 pressed to see how it can, unless gcmd.Command() is doing a '''lot''' of
 scary magic on the mess it gets passed.

-- 
Ticket URL: <https://trac.osgeo.org/grass/ticket/693#comment:11>
GRASS GIS <http://grass.osgeo.org>