Add a check that makes sure PDO is available

Calling an unavailable class is a fatal error, so people without PDO
were left with a fairly useless blank screen and no indicator of what
was wrong. Let's be a bit more user-friendly.

2 files changed, 14 insertions, 1 deletions

diff --git a/lib/debug.lib.php b/lib/debug.lib.php
index f1c5dbcc..f96c9ffa 100644
--- a/lib/debug.lib.php
+++ b/lib/debug.lib.php
@@ -74,6 +74,19 @@ function check_php_pcre() {
 } // check_php_pcre
 
 /**
+ * check_pdo
+ *
+ * Checks to make sure that PDO is available.
+ */
+function check_pdo() {
+    if (class_exists('PDO') && in_array('mysql', PDO::getAvailableDrivers())) {
+        return true;
+    }
+
+    return false;
+}
+
+/**
  * check_config_values
  * checks to make sure that they have at least set the needed variables
  */
diff --git a/lib/init.php b/lib/init.php
index 9955c088..8b8248f0 100644
--- a/lib/init.php
+++ b/lib/init.php
@@ -53,7 +53,7 @@ else {
 
 // Verify that a few important but commonly disabled PHP functions exist and
 // that we're on a usable version
-if (!function_exists('hash') || !function_exists('inet_pton') || (floatval(phpversion()) < 5.3)) {
+if (!function_exists('hash') || !function_exists('inet_pton') || (floatval(phpversion()) < 5.3) || !class_exists('PDO')) {
     $link = $path . '/test.php';
 }