Refactored fetching and checking out of missing repos in kas.config

The current implementation did some more hackish solution to work
around some of kas infrastructure, without changing to much.

This patch cleans this up and therefor remove the more obsure part
of the include mechansim.

Signed-off-by: Claudius Heine <ch@denx.de>

kas/libkas.py

@@ -158,6 +158,78 @@ def find_program(paths, name):
     return None
 
 
+def repo_fetch(config, repo):
+    """
+        Fetches the repository to the kas_work_dir.
+    """
+    if repo.git_operation_disabled:
+        return
+
+    if not os.path.exists(repo.path):
+        os.makedirs(os.path.dirname(repo.path), exist_ok=True)
+        gitsrcdir = os.path.join(config.get_repo_ref_dir() or '',
+                                 repo.qualified_name)
+        logging.debug('Looking for repo ref dir in %s', gitsrcdir)
+        if config.get_repo_ref_dir() and os.path.exists(gitsrcdir):
+            run_cmd(['/usr/bin/git',
+                     'clone',
+                     '--reference', gitsrcdir,
+                     repo.url, repo.path],
+                    env=config.environ,
+                    cwd=config.kas_work_dir)
+        else:
+            run_cmd(['/usr/bin/git', 'clone', '-q', repo.url,
+                     repo.path],
+                    env=config.environ,
+                    cwd=config.kas_work_dir)
+        return
+
+    # Does refspec in the current repository?
+    (retc, output) = run_cmd(['/usr/bin/git', 'cat-file',
+                              '-t', repo.refspec], env=config.environ,
+                             cwd=repo.path, fail=False)
+    if retc == 0:
+        return
+
+    # No it is missing, try to fetch
+    (retc, output) = run_cmd(['/usr/bin/git', 'fetch', '--all'],
+                             env=config.environ,
+                             cwd=repo.path, fail=False)
+    if retc:
+        logging.warning('Could not update repository %s: %s',
+                        repo.name, output)
+
+
+def repo_checkout(config, repo):
+    """
+        Checks out the correct revision of the repo.
+    """
+    if repo.git_operation_disabled:
+        return
+
+    # Check if repos is dirty
+    (_, output) = run_cmd(['/usr/bin/git', 'diff', '--shortstat'],
+                          env=config.environ, cwd=repo.path,
+                          fail=False)
+    if len(output):
+        logging.warning('Repo %s is dirty. no checkout', repo.name)
+        return
+
+    # Check if current HEAD is what in the config file is defined.
+    (_, output) = run_cmd(['/usr/bin/git', 'rev-parse',
+                           '--verify', 'HEAD'],
+                          env=config.environ, cwd=repo.path)
+
+    if output.strip() == repo.refspec:
+        logging.info('Repo %s has already checkout out correct '
+                     'refspec. nothing to do', repo.name)
+        return
+
+    run_cmd(['/usr/bin/git', 'checkout', '-q',
+             '{refspec}'.format(refspec=repo.refspec)],
+            cwd=repo.path)
+
+
 def get_build_environ(config, build_dir):
     """
         Create the build environment variables.