__unicode__(): Fix the logic for calculating whether to add a
separating space or not between encoded chunks. Closes SF bug
#710498.
diff --git a/Lib/email/Header.py b/Lib/email/Header.py
index 624e7c4..76fffb5 100644
--- a/Lib/email/Header.py
+++ b/Lib/email/Header.py
@@ -215,11 +215,11 @@
# charset. Only do this for the second and subsequent chunks.
nextcs = charset
if uchunks:
- if lastcs is not None:
- if nextcs is None or nextcs == 'us-ascii':
+ if lastcs not in (None, 'us-ascii'):
+ if nextcs in (None, 'us-ascii'):
uchunks.append(USPACE)
nextcs = None
- elif nextcs is not None and nextcs <> 'us-ascii':
+ elif nextcs not in (None, 'us-ascii'):
uchunks.append(USPACE)
lastcs = nextcs
uchunks.append(unicode(s, str(charset)))