getScreenWidth() returns an invalid width of zero

[Camilo]

Smart versions: .52 and 1.1

Under a very specific condition, such as when using pexpect to spawn a smart process to do some work from turbo gears web server, smart fails to get a valid screen width when calling getScreenWidth(). In this environment it returns a value of zero which in turn creates problems later on by generating a badly formed self._topicmaskn inside interfaces/text/progress.py TextProgress.setScreenWidth() method.

the workaround is to change the following code from interface.py:

def getScreenWidth():
    s = struct.pack('HHHH', 0, 0, 0, 0)
    try:
        x = fcntl.ioctl(1, termios.TIOCGWINSZ, s)
    except IOError:
        return 80
    return struct.unpack('HHHH', x)[1]

to:

def getScreenWidth():
    s = struct.pack('HHHH', 0, 0, 0, 0)
    try:
        x = fcntl.ioctl(1, termios.TIOCGWINSZ, s)
    except IOError:
        return 80
    width = struct.unpack('HHHH', x)[1]
    if width > 0:
        return width
    else:
        return 80

which ensures returning a valid default value when the width is reported to be zero or less than zero.

Camilo

[Anders F Björklund (afb)]

This was also in openSUSE, as smart-0.52-termios-0width.patch:

* Sat Jan 26 2008 guru AT unixtech.be
- added patch to fix terminal width determination on serial and xen consoles

[Gustavo Niemeyer (niemeyer)]

That's been fixed in trunk with proper testing.

[Anders F Björklund (afb)]

Released, 2009-03-04