Re: [PATCH for-4.5 RFC] pygrub: Fix regression from c/s d1b93ea, attempt 2

[Ian Campbell <Ian.Campbell@citrix.com>]

On Mon, 2014-11-17 at 15:19 +0000, Andrew Cooper wrote:
> c/s d1b93ea causes substantial functional regressions in pygrub's ability to
> parse bootloader configuration files.
> 
> c/s d1b93ea itself changed an an interface which previously used exclusively
> integers, to using strings in the case of a grub configuration with explicit
> default set, along with changing the code calling the interface to require a
> string.  The default value for "default" remained as an integer.
> 
> As a result, any Extlinux or Lilo configuration (which drives this interface
> exclusively with integers), or Grub configuration which doesn't explicitly
> declare a default will die with an AttributeError when attempting to call
> "self.cf.default.isdigit()" where "default" is an integer.
> 
> Sadly, this AttributeError gets swallowed by the blanket ignore in the loop
> which searches partitions for valid bootloader configurations, causing the
> issue to be reported as "Unable to find partition containing kernel"
> 
> This patch attempts to fix the issue by altering all parts of this interface
> to use strings, as opposed to integers.

Would it be less invasive at this point in the release to have the place
where this stuff is used do isinstance(s, str) and isinstance(s, int)?

Also, in run_grub sel can be set to g.cf.default and then:
    if sel == -1:
        print "No kernel image selected!"
        sys.exit(1)

I can't see where the -1 comes from though, and you aren't changing any
-1 into "-1", so maybe something more subtle is going on there.

Ian.