[OE-core] [PATCH] terminal: fix issue with unset exportable env vars

[Chris Larson]

From: Chris Larson <chris_larson at mentor.com>

This should resolve the devshell issue people are seeing.

Signed-off-by: Chris Larson <chris_larson at mentor.com>
---
 meta/classes/terminal.bbclass |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/meta/classes/terminal.bbclass b/meta/classes/terminal.bbclass
index 4123046..f29aeb0 100644
--- a/meta/classes/terminal.bbclass
+++ b/meta/classes/terminal.bbclass
@@ -30,7 +30,9 @@ def oe_terminal(command, title, d):
 
     env = dict(os.environ)
     for export in oe.data.typed_value('OE_TERMINAL_EXPORTS', d):
-        env[export] = d.getVar(export, True)
+        value = d.getVar(export, True)
+        if value is not None:
+            env[export] = str(value)
 
     try:
         oe.terminal.spawn_preferred(command, title, env)
-- 
1.7.4.1