Index: user/externallib.php
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
--- user/externallib.php	(revision afbb53d70b6f53d529c568e87305bfb187601239)
+++ user/externallib.php	(revision )
@@ -189,7 +189,7 @@
             // Make sure we validate current user info as handled by current GUI. See user/editadvanced_form.php func validation().
             if (!validate_email($user['email'])) {
                 throw new invalid_parameter_exception('Email address is invalid: '.$user['email']);
-            } else if ($DB->record_exists('user', array('email' => $user['email'], 'mnethostid' => $user['mnethostid']))) {
+            } else if (empty($CFG->allowaccountssameemail) && $DB->record_exists('user', array('email' => $user['email'], 'mnethostid' => $user['mnethostid']))) {
                 throw new invalid_parameter_exception('Email address already exists: '.$user['email']);
             }
             // End of user info validation.