ktl: simplify and fix debian changelog detection

The debian changelog is in one of three places.  It is either in a branch
specific changelog, debian/changelog, or meta-source/debian/changelog.
Where a branch specific changelog is present it is always identified via
the debian/debian.env DEBIAN=<directory> stanza.  Move to using this to
identify the correct debian changelog.  Also move to using a loop over
the possible locations.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
---
 ktl/debian.py |   54 ++++++++++++++++++------------------------------------
 1 files changed, 18 insertions(+), 36 deletions(-)

On Fri, 2011-06-10 at 14:28 +0100, Andy Whitcroft wrote:
> The debian changelog is in one of three places.  It is either in a branch
> specific changelog, debian/changelog, or meta-source/debian/changelog.
> Where a branch specific changelog is present it is always identified via
> the debian/debian.env DEBIAN=<directory> stanza.  Move to using this to
> identify the correct debian changelog.  Also move to using a loop over
> the possible locations.
> 
> Signed-off-by: Andy Whitcroft <apw@canonical.com>

Acked-by: Leann Ogasawara <leann.ogasawara@canonical.com>

And just in case it's not obvious to everyone:

http://people.canonical.com/~kernel/reports/scripts/ktl/README

"ktl - kteam-tools library

A python module for use in any kteam-tools scripts. A module gives you
namespace separation and a cleaner design."

> ---
>  ktl/debian.py |   54 ++++++++++++++++++------------------------------------
>  1 files changed, 18 insertions(+), 36 deletions(-)
> 
> diff --git a/ktl/debian.py b/ktl/debian.py
> index 002ecf4..789e795 100644
> --- a/ktl/debian.py
> +++ b/ktl/debian.py
> @@ -41,52 +41,34 @@ class Debian:
>          #
>          current_branch = Git.current_branch()
>  
> -        # The standard location for a changelog is in a directory named 'debian'.
> -        #
> -        cl_path = 'debian/changelog'
> -        debug("Trying '%s': " % cl_path, cls.debug)
> +        # If we have a debian/debian.env then open and extract the DEBIAN=...
> +        # location.
> +        debug("Checking debian/debian.env", cls.debug)
> +        cl_paths = []
>          try:
> -            retval = Git.show(cl_path, branch=current_branch)
> +            debian_env = Git.show("debian/debian.env", branch=current_branch)
> +            for line in debian_env:
> +                (var, val) = line.split('=', 1)
> +                val = val.rstrip()
> +
> +                if var == 'DEBIAN':
> +                    cl_paths.append(val + "/changelog")
>              debug("SUCCEEDED\n", cls.debug, False)
>          except GitError:
>              debug("FAILED\n", cls.debug, False)
> -            # If this is a kernel tree, the changelog is in a debian.<branch> directory.
> -            #
> -            cl_path = 'debian.' + current_branch + '/changelog'
> +
> +        # Try probabal paths.
> +        cl_paths += [ 'debian/changelog', 'meta-source/debian/changelog' ]
> +        for cl_path in cl_paths:
>              debug("Trying '%s': " % cl_path, cls.debug)
>              try:
>                  retval = Git.show(cl_path, branch=current_branch)
> -                debug("SUCCEEDED\n", cls.debug, False)
> +                return retval, cl_path
>              except GitError:
>                  debug("FAILED\n", cls.debug, False)
> -                # If this is a 'backport' kernel then it could be in the debian.<series>
> -                # directory.
> -                #
> -                debug('Getting the series from the Makefile: ', cls.debug)
> -                try:
> -                    series = Kernel.series_name()
> -                    debug("SUCCEEDED\n", cls.debug, False)
> -
> -                    cl_path = 'debian.' + series + '/changelog'
> -                    debug("Trying '%s': " % cl_path, cls.debug)
> -                    retval = Git.show(cl_path, branch=current_branch)
> -                    debug("SUCCEEDED\n", cls.debug, False)
> -                except GitError:
> -                    debug("FAILED\n", cls.debug, False)
> -
> -                    # If this is a kernel meta package, its in a sub-directory of meta-source.
> -                    #
> -                    if path.exists('meta-source'):
> -                        cl_path = 'meta-source/debian/changelog'
> -                        debug("Trying '%s': " % cl_path, cls.debug)
> -                        try:
> -                            retval = Git.show(cl_path, branch=current_branch)
> -                        except GitError:
> -                            debug("FAILED\n", cls.debug, False)
> -                            raise DebianError('Failed to find the changelog.')
> -                    else:
> -                        raise DebianError('Failed to find the changelog.')
> -        return retval, cl_path
> +
> +        # Not there anywhere, barf
> +        raise DebianError('Failed to find the changelog.')
>  
>      # changelog
>      #
> -- 
> 1.7.4.1
> 
>