[bugfix] Fix bug in action=clientlogin

Change-Id: Ie844691acb35e8e923f6b4995f72c6b33b74e7ac
---
M pywikibot/data/api.py
1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/pywikibot/data/api.py b/pywikibot/data/api.py
index 3f85140..9d54333 100644
--- a/pywikibot/data/api.py
+++ b/pywikibot/data/api.py
@@ -3107,11 +3107,6 @@
 
         below_mw_1_27 = self.site.mw_version < '1.27'
 
-        # prepare default login parameters
-        parameters = {'action': self.action,
-                      self.keyword('user'): self.login_name,
-                      self.keyword('password'): self.password}
-
         if '@' in self.login_name or '@' in self.password or below_mw_1_27:
             # Since MW 1.27 only for bot passwords.
             # Bot passwords username contains @,
@@ -3123,6 +3118,12 @@
             # Standard login request since MW 1.27
             self.action = 'clientlogin'
 
+        # prepare default login parameters
+        parameters = {'action': self.action,
+                      self.keyword('user'): self.login_name,
+                      self.keyword('password'): self.password}
+
+        if self.action == 'clientlogin':
             # clientlogin requires non-empty loginreturnurl
             parameters['loginreturnurl'] = 'https://example.com'
 

