filtering of commands during async operation

[Doug Evans]

Newman, Mark (N-Superior Technical Resource Inc) writes:
 > 
 > In top.c there is an attempt to filter what commands can be issued during async operation.  That code is not filtering (at least under RH on an Intel box).  The code is
 > 
 > if (event_loop_p && target_can_async_p () && target_executing)
 > if (!strcmp (c->name, "help")
 > 	    && !strcmp (c->name, "pwd")
 > 	    && !strcmp (c->name, "show")
 > 	    && !strcmp (c->name, "stop"))
 > error ("Cannot execute this command while the target is running.");

Good example of why it's useful to avoid using ! with strcmp.

 > The code should be:
 > 
 > if (event_loop_p && target_can_async_p () && target_executing) {
 >    if (!(strcmp (c->name, "help") == 0)
 > 	    && !(strcmp (c->name, "pwd") == 0)
 > 	    && !(strcmp (c->name, "show") == 0)
 > 	    && !(strcmp (c->name, "stop") == 0)) {
 >    error ("Cannot execute this command while the target is running.");
 >    }
 > }
 > 
 > Unless someone objects I am going to put in a bug report and a patch.

Why not just strcmp () != 0