consistency check: don't raise 'no user found' exception when the

backend accidentally returns two users

2 files changed, 10 insertions, 2 deletions

diff --git a/account.py b/account.py
index 2ac3248..33ac349 100644
--- a/account.py
+++ b/account.py
@@ -100,8 +100,10 @@ class AccountService:
         raise NoSuchUserError if there is no such user.
         """
         users = self.find_by_uid(uid)
-        if len(users) != 1:
+        if len(users) == 0:
             raise NoSuchUserError('No such user')
+        if len(users) > 1:
+            raise ShouldNotHappen('Several users for one uid returned.')
 
         return users[0]
 
@@ -111,8 +113,10 @@ class AccountService:
         raise NoSuchUserError if there is no such user.
         """
         users = self.find_by_mail(mail)
-        if len(users) != 1:
+        if len(users) == 0:
             raise NoSuchUserError('No such user')
+        if len(users) > 1:
+            raise ShouldNotHappen('Several users for one mail returned.')
 
         return users[0]
 
diff --git a/utils.py b/utils.py
index ca0fb16..7071284 100644
--- a/utils.py
+++ b/utils.py
@@ -239,3 +239,7 @@ def url_for(endpoint, **values):
         return 'https://' + u[7:]
     else:
         return u
+
+# used when we encounter inconsistent data etc
+class ShouldNotHappen(RuntimeError):
+    pass