Wrong frequency when purchasing a membership

We patched a bug in CiviCRM core that has been around for a while now. When buying an annual membership, sometimes donors are charged the annual price, but on a monthly basis. (We offer both annual and monthly memberships on the same membership page). This patch is a hack that works for us, but may have some hard coded values for our instance.

One way to check if your server has this problem is to use a payment processor like PayPal, which lets you see the recurring contrib details before you actually pay. This issue comes up somewhat randomly, so you might have to try a few times.

Thanks! : )

diff --git a/CRM/Contribute/Form/ContributionBase.php b/CRM/Contribute/Form/ContributionBase.php
index 41fcb7da3e..075d29ab20 100644
--- a/CRM/Contribute/Form/ContributionBase.php
+++ b/CRM/Contribute/Form/ContributionBase.php
@@ -1371,7 +1371,14 @@ class CRM_Contribute_Form_ContributionBase extends CRM_Core_Form {
       $this->_params['is_recur'] = $this->_values['is_recur'] = 1;
       // check if price set is not quick config
       if (!empty($this->_params['priceSetId']) && !CRM_Core_DAO::getFieldValue('CRM_Price_DAO_PriceSet', $this->_params['priceSetId'], 'is_quick_config')) {
-        list($this->_params['frequency_interval'], $this->_params['frequency_unit']) = CRM_Price_BAO_PriceSet::getRecurDetails($this->_params['priceSetId']);
+
+        // Extract the ids for all of the line items that have been chosen.
+        $priceFieldValueIds = array_keys($this->_lineItem[$this->_params['priceSetId']])[0];
+        if (empty($priceFieldValueIds))
+          $priceFieldValueIds = array_keys($this->_params['price_126'])[0];
+        list($this->_params['frequency_interval'], $this->_params['frequency_unit']) = CRM_Price_BAO_PriceSet::getRecurDetails($this->_params['priceSetId'], $priceFieldValueIds);
       }
       else {
         // FIXME: set interval and unit based on selected membership type
diff --git a/CRM/Price/BAO/PriceSet.php b/CRM/Price/BAO/PriceSet.php
index 91118ecd97..0277bdbaed 100644
--- a/CRM/Price/BAO/PriceSet.php
+++ b/CRM/Price/BAO/PriceSet.php
@@ -1332,13 +1332,14 @@ GROUP BY     mt.member_of_contact_id ";
    * @return array
    *   associate array of frequency interval and unit
    */
-  public static function getRecurDetails($priceSetId) {
+  public static function getRecurDetails($priceSetId, $priceFieldValueIds) {
 
     $query = 'SELECT mt.duration_interval, mt.duration_unit
             FROM civicrm_price_field_value pfv
             INNER JOIN civicrm_membership_type mt ON pfv.membership_type_id = mt.id
             INNER JOIN civicrm_price_field pf ON pfv.price_field_id = pf.id
-            WHERE pf.price_set_id = %1 LIMIT 1';
+            WHERE pf.price_set_id = %1 AND pfv.id = '
+            . $priceFieldValueIds . ' LIMIT 1';
 
     $params = [1 => [$priceSetId, 'Integer']];
     $dao = CRM_Core_DAO::executeQuery($query, $params);