[gnome-continuous-yocto/gnomeostree-3.28-rocko: 3758/8267] oeqa/utils/commands.py: Fix get_bb_vars() when called without arguments

[Emmanuele Bassi <ebassi src gnome org>]

commit a92d27acd8f42b61a2fc575311838b45d171f0af
Author: Mariano Lopez <mariano lopez linux intel com>
Date:   Wed Dec 14 07:45:21 2016 +0000

    oeqa/utils/commands.py: Fix get_bb_vars() when called without arguments
    
    Commit 9d55e9d489cd78be592fb9b4d6484f9060c62fdd broke calling get_bb_vars()
    when called without arguments. This fix this issue.
    
    (From OE-Core rev: 91f856426c7523e1ebdf6d6f93f5fa7e509d6e49)
    
    Signed-off-by: Mariano Lopez <mariano lopez linux intel com>
    Signed-off-by: Richard Purdie <richard purdie linuxfoundation org>

 meta/lib/oeqa/utils/commands.py |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/meta/lib/oeqa/utils/commands.py b/meta/lib/oeqa/utils/commands.py
index 6acb24a..aecf8cf 100644
--- a/meta/lib/oeqa/utils/commands.py
+++ b/meta/lib/oeqa/utils/commands.py
@@ -149,7 +149,8 @@ def get_bb_vars(variables=None, target=None, postconfig=None):
     """Get values of multiple bitbake variables"""
     bbenv = get_bb_env(target, postconfig=postconfig)
 
-    variables = variables.copy()
+    if variables is not None:
+        variables = variables.copy()
     var_re = re.compile(r'^(export )?(?P<var>\w+)="(?P<value>.*)"$')
     unset_re = re.compile(r'^unset (?P<var>\w+)$')
     lastline = None