db/message: work around python bug 39100

1 files changed, 36 insertions, 5 deletions

diff --git a/alot/db/message.py b/alot/db/message.py
index 4a7728ee..014218a6 100644
--- a/alot/db/message.py
+++ b/alot/db/message.py
@@ -63,30 +63,61 @@ class _MessageHeaders:
     def __contains__(self, key):
         return key in self._msg
 
+    # workaround for https://bugs.python.org/issue39100
+    def _exc_is_bp39100(self, e):
+        if (e.args and len(e.args) >= 1 and
+            'Group' in e.args[0] and 'local_part' in e.args[0]):
+            logging.error('Working around Python bug 39100')
+            return True
+        return False
+
+    def _get_all_wrapper(self, key, failobj = None):
+        try:
+            return self._msg.get_all(key, failobj)
+        except AttributeError as e:
+            if self._exc_is_bp39100(e):
+                return []
+            raise
+
     def __getitem__(self, key):
         if not key in self._msg:
             raise KeyError(key)
-        return self._msg.get_all(key)
+        return self._get_all_wrapper(key)
 
     def get(self, key):
         """
         Get the value of the first header with the name equal to key,
         None if the header is not present.
         """
-        return self._msg.get(key)
+        try:
+            return self._msg.get(key)
+        except AttributeError as e:
+            if self._exc_is_bp39100(e):
+                return []
+            raise
 
     def get_all(self, key):
         """
         Get the list of all values of the header with the name equal to key,
         empty list of the header is not present.
         """
-        return self._msg.get_all(key, [])
+        return self._get_all_wrapper(key, [])
 
     def keys(self):
-        return self._msg.keys()
+        try:
+            return self._msg.keys()
+        except AttributeError as e:
+            if self._exc_is_bp39100(e):
+                return []
+            raise
 
     def items(self):
-        return self._msg.items()
+        try:
+            return self._msg.items()
+        except AttributeError as e:
+            if self._exc_is_bp39100(e):
+                return []
+            raise
 
 class _MimeTree:
     _part = None