Fix email commas.

Author: isoos

app/lib/service/email/email_templates.dart

@@ -86,6 +86,9 @@ bool isValidEmail(String email) {
   // strict pattern check
   if (!_strictEmailRegExp.hasMatch(email)) return false;
 
+  // also reject commas
+  if (email.contains(',')) return false;
+
   // checking for IPv4 or IPv6 addresses
   var isInternetAddress = false;
   try {

app/test/service/email/email_templates_test.dart

@@ -98,6 +98,10 @@ void main() {
       // verify that we have rejected emails
       expect(rejectedEmails, hasLength(215));
     });
+
+    test('reject multiple addresses', () {
+      expect(isValidEmail('[email protected],[email protected]'), false);
+    });
   });
 
   group('EmailAddress format', () {