[yocto] [autobuilder][PATCH] CreateAutoConf.py: check for empty env history variables before using

[Bill Randle]

I saw this error on a new AB setup:

File "/home/pokybuild/yocto-autobuilder/lib/python2.7/site-packages/autobuilder/buildsteps/CreateAutoConf.py", line 181, in start
    ta_history_repos=ast.literal_eval(os.environ.get('BUILD_HISTORY_THROWAWAY_WHITELIST').encode('utf-8'))
    exceptions.AttributeError: 'NoneType' object has no attribute 'encode'

Since the code above line 181 checks for either BUILD_HISTORY_THROWAWAY_WHITELIST
or BUILD_HISTORY_WHITELIST being set, it's possible one of them could be empty.

Signed-off-by: Bill Randle <william.c.randle at intel.com>
---
 .../site-packages/autobuilder/buildsteps/CreateAutoConf.py        | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/lib/python2.7/site-packages/autobuilder/buildsteps/CreateAutoConf.py b/lib/python2.7/site-packages/autobuilder/buildsteps/CreateAutoConf.py
index 0845ff1..91607e6 100644
--- a/lib/python2.7/site-packages/autobuilder/buildsteps/CreateAutoConf.py
+++ b/lib/python2.7/site-packages/autobuilder/buildsteps/CreateAutoConf.py
@@ -177,9 +177,13 @@ class CreateAutoConf(ShellCommand):
 
                 if os.environ.get('BUILD_HISTORY_WHITELIST') is not None or \
                    os.environ.get('BUILD_HISTORY_THROWAWAY_WHITELIST') is not None:
+                    ta_history_repos={}
+                    history_repos={}
                     fout = fout + 'ERROR_QA_remove = "version-going-backwards"\n'
-                    ta_history_repos=ast.literal_eval(os.environ.get('BUILD_HISTORY_THROWAWAY_WHITELIST').encode('utf-8'))
-                    history_repos=ast.literal_eval(os.environ.get('BUILD_HISTORY_WHITELIST').encode('utf-8'))
+                    if os.environ.get('BUILD_HISTORY_THROWAWAY_WHITELIST') is not None:
+                        ta_history_repos=ast.literal_eval(os.environ.get('BUILD_HISTORY_THROWAWAY_WHITELIST').encode('utf-8'))
+                    if os.environ.get('BUILD_HISTORY_WHITELIST') is not None:
+                        history_repos=ast.literal_eval(os.environ.get('BUILD_HISTORY_WHITELIST').encode('utf-8'))
                     if repo in history_repos.keys() and \
                        self.getProperty("branch") in history_repos[self.getProperty("repository")]:
                     # We keep this build history
-- 
2.5.5