From 0828e4ad344b4435796eb5e821b4233e3121e611 Mon Sep 17 00:00:00 2001
From: Tim Otten <totten@civicrm.org>
Date: Fri, 14 Oct 2016 15:17:20 +0100
Subject: [PATCH] CRM-19505 - CRM_Core_Error::handle() - Fix detection of mysql
 driver

The check `preg_match('/^mysql:/', $_DB_DATAOBJECT['CONFIG']['database'])`
assumes that the admin is manually changing `CIVICRM_DSN` to indicate
preferred driver. Since we determine the driver automatically in 4.7.12+,
this check doesn't work.

This new check determines what driver is actually in use.
---
 CRM/Core/Error.php | 39 ++++++++++++++++++---------------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/CRM/Core/Error.php b/CRM/Core/Error.php
index 482ccad7d9..e9941373dc 100644
--- a/CRM/Core/Error.php
+++ b/CRM/Core/Error.php
@@ -195,32 +195,29 @@ class CRM_Core_Error extends PEAR_ErrorStack {
     // can avoid infinite loops.
     global $_DB_DATAOBJECT;
 
-    if (!isset($_DB_DATAOBJECT['CONFIG']['database'])) {
-      // we haven't setup sql, so it's not our sql error...
-    }
-    elseif (preg_match('/^mysql:/', $_DB_DATAOBJECT['CONFIG']['database']) &&
-      mysql_error()
-    ) {
-      $mysql_error = mysql_error() . ', ' . mysql_errno();
-      $template->assign_by_ref('mysql_code', $mysql_error);
-
-      // execute a dummy query to clear error stack
-      mysql_query('select 1');
-    }
-    elseif (preg_match('/^mysqli:/', $_DB_DATAOBJECT['CONFIG']['database'])) {
+    if (isset($_DB_DATAOBJECT['CONFIG']['database'])) {
       $dao = new CRM_Core_DAO();
-
       if (isset($_DB_DATAOBJECT['CONNECTIONS'][$dao->_database_dsn_md5])) {
         $conn = $_DB_DATAOBJECT['CONNECTIONS'][$dao->_database_dsn_md5];
-        $link = $conn->connection;
 
-        if (mysqli_error($link)) {
-          $mysql_error = mysqli_error($link) . ', ' . mysqli_errno($link);
-          $template->assign_by_ref('mysql_code', $mysql_error);
-
-          // execute a dummy query to clear error stack
-          mysqli_query($link, 'select 1');
+        // FIXME: Polymorphism for the win.
+        if ($conn instanceof DB_mysqli) {
+          $link = $conn->connection;
+          if (mysqli_error($link)) {
+            $mysql_error = mysqli_error($link) . ', ' . mysqli_errno($link);
+            mysqli_query($link, 'select 1'); // execute a dummy query to clear error stack
+          }
+        }
+        elseif ($conn instanceof DB_mysql) {
+          if (mysql_error()) {
+            $mysql_error = mysql_error() . ', ' . mysql_errno();
+            mysql_query('select 1'); // execute a dummy query to clear error stack
+          }
+        }
+        else {
+          $mysql_error = 'fixme-unknown-db-cxn';
         }
+        $template->assign_by_ref('mysql_code', $mysql_error);
       }
     }
 
-- 
2.25.1