bug#1688: 23.0.60; ttname returned by system-process-attributes points to nonexisting file

[richardeng]

Stefan Monnier wrote:
> > > --- sysdep.c.~1.328.~   2009-01-03 07:04:59.000000000 -0800
> > > +++ sysdep.c    2009-01-13 01:09:56.000000000 -0800
> > > @@ -3322,7 +3322,7 @@
> > >
> > > if (MINOR (rdev) >= minor_beg && MINOR (rdev) <= minor_end)
> > > {
> > > -                  sprintf (name + strlen (name), "%lu", MINOR (rdev));
> > > +                  sprintf (name + strlen (name), "/%lu", MINOR (rdev));
> > > break;
> > > }                                                                                              
> > >       
> > It's not that simple: what happens if `name' is something like "ptys"
> > or "tty"?  We need to generate "ptys2" and "tty39" for them, not
> > "ptys/2" and "tty/39".
> >     
>
> Indeed, it's pretty messy.  Even just procfs_ttyname in itself is pretty
> messy (not its implementation, but the need to go through those hoops).
>
>   
> > Faced with this difficulty, I decided not to bother, since the value
> > of `ttname' is not documented to return a valid file name.
> >     
>
>   
> > Perhaps some Linux guru (which I ain't) can suggest an easy solution.
> >     
>
> I think it's OK for now.  When we really need something better, we'll
> just look at the `ps' code.
>
>
>         Stefan
>
>
>   
check ISDIR first


--- sysdep.c.~1.328.~   2009-01-03 07:04:59.000000000 -0800                                                    
+++ sysdep.c    2009-01-15 02:03:07.000000000 -0800                                                            
@@ -3322,7 +3322,11 @@
                                                                                                              
             if (MINOR (rdev) >= minor_beg && MINOR (rdev) <= minor_end)                                      
               {                                                                                              
-                 sprintf (name + strlen (name), "%lu", MINOR (rdev));                                         
+                 struct stat st_addr;                                                                         
+                 if (!stat (name, &st_addr) && S_ISDIR(st_addr.st_mode))                                      
+                   sprintf (name + strlen (name), "/%lu", MINOR (rdev));                                      
+                 else                                                                                         
+                   sprintf (name + strlen (name), "%lu", MINOR (rdev));                                       
                 break;                                                                                       
               }                                                                                              
           }