add a db_version and a feature check function to determine if we support skip locks in the query. Use it to disable the feature in filter view.

web/includes/database.php

@@ -379,4 +379,24 @@ function getTableDescription( $table, $asString=1 ) {
   }
   return $columns;
 }
+
+function db_version() {
+  return dbFetchOne('SELECT VERSION()', 'VERSION()');
+}
+
+function db_supports_feature($feature) {
+  $version = db_version();
+  if ($feature == 'skip_locks') {
+    $just_the_version = strstr($version, '-MariaDB', true);
+    ZM\Debug("Just the version $just_the_version from $version");
+    if (false === $just_the_version) {
+      # Is MYSQL
+      return version_compare($version, '8.0.1', '>=');
+    } else {
+      return version_compare($just_the_version, '10.6', '>=');
+    }
+  } else {
+    ZM\Warning("Unknown feature requested $feature");
+  }
+}
 ?>

web/skins/classic/views/filter.php

@@ -218,7 +218,10 @@ echo htmlSelect('filter[Query][sort_asc]', $sort_dirns, $filter->sort_asc());
 <?php
 echo htmlSelect('filter[Query][skip_locked]',
   array('0'=>translate('No'), '1'=>translate('Yes')),
-  $filter->skip_locked());
+  $filter->skip_locked(),
+  ( db_supports_feature('skip_locks') ? []: ['disabled'=>'disabled', 'title'=>'Database does not support the skip locked feature.'])
+);
+
 ?>
               </td>
               <td>