Make sure that admins cannot duplicate an email address (same email

for more then one user) as this messes up mailman. Besides, we will
eventually have to switch to email uids at some point, so they will
need to be unique anyway.

www/dbdefs.php3.in

@@ -2023,6 +2023,20 @@ function TBGetVersionInfo(&$major, &$minor, &$build)
     return 1;
 }
 
+#
+# Is email address unique?
+#
+function TBUniqueEmail($uid, $email)
+{
+    $query_result =
+	DBQueryFatal("select usr_email from users where ".
+		     "usr_email='$email' and uid!='$uid'");
+
+    if (mysql_num_rows($query_result))
+	return 0;
+    return 1;
+}
+
 #
 # DB Interface.
 #

www/moduserinfo.php3

@@ -519,6 +519,9 @@ if (!isset($formfields[usr_email]) ||
 elseif (! TBvalid_email($formfields[usr_email])) {
     $errors["Email Address"] = TBFieldErrorString();
 }
+elseif (! TBUniqueEmail($target_uid, $formfields[usr_email])) {
+    $errors["Email Address"] = "Already in use by another user!";
+}
 if (!$isadmin && !$wikionly) {
     # Admins can leave these fields blank, but must error check them anyway.
     if (!isset($formfields[usr_addr]) ||