Allow deletion of kindle email address and force e-mail address to be valid

cps/admin.py

@@ -1960,8 +1960,11 @@ def _handle_edit_user(to_save, content, languages, translations, kobo_support):
         if to_save.get("locale"):
             content.locale = to_save["locale"]
         try:
-            if to_save.get("email", content.email) != content.email:
-                content.email = check_email(to_save["email"])
+            new_email = check_email(to_save.get("email", content.email))
+            if not new_email:
+                raise Exception(_(u"E-Mail Address can't be empty and has to be a valid E-Mail"))
+            if new_email != content.email:
+                content.email = new_email
             # Query username, if not existing, change
             if to_save.get("name", content.name) != content.name:
                 if to_save.get("name") == "Guest":

cps/helper.py

@@ -654,11 +654,13 @@ def check_username(username):
 
 def valid_email(email):
     email = email.strip()
-    # Regex according to https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/email#validation
-    if not re.search(r"^[\w.!#$%&'*+\\/=?^_`{|}~-]+@[\w](?:[\w-]{0,61}[\w])?(?:\.[\w](?:[\w-]{0,61}[\w])?)*$",
-                     email):
-        log.error(u"Invalid e-mail address format")
-        raise Exception(_(u"Invalid e-mail address format"))
+    # if email is not deleted
+    if email:
+        # Regex according to https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/email#validation
+        if not re.search(r"^[\w.!#$%&'*+\\/=?^_`{|}~-]+@[\w](?:[\w-]{0,61}[\w])?(?:\.[\w](?:[\w-]{0,61}[\w])?)*$",
+                         email):
+            log.error(u"Invalid e-mail address format")
+            raise Exception(_(u"Invalid e-mail address format"))
     return email
 
 # ################################# External interface #################################

cps/web.py

@@ -1364,8 +1364,11 @@ def change_profile(kobo_support, local_oauth_check, oauth_status, translations,
     try:
         if to_save.get("kindle_mail", current_user.kindle_mail) != current_user.kindle_mail:
             current_user.kindle_mail = valid_email(to_save.get("kindle_mail"))
-        if to_save.get("email", current_user.email) != current_user.email:
-            current_user.email = check_email(to_save.get("email"))
+        new_email = check_email(to_save.get("email", current_user.email))
+        if not new_email:
+            raise Exception(_(u"E-Mail Address can't be empty and has to be a valid E-Mail"))
+        if new_email != current_user.email:
+            current_user.email = new_email
         if current_user.role_admin():
             if to_save.get("name", current_user.name) != current_user.name:
                 # Query username, if not existing, change