Issue #2454733 by amateescu: Add a user-space case-insensitive collation to the SQLite driver

core/lib/Drupal/Component/Utility/Unicode.php

@@ -541,6 +541,22 @@ EOD;
     return $string;
   }
 
+  /**
+   * Compares UTF-8-encoded strings in a binary safe case-insensitive manner.
+   *
+   * @param string $str1
+   *   The first string.
+   * @param string $str2
+   *   The second string.
+   *
+   * @return int
+   *   Returns < 0 if $str1 is less than $str2; > 0 if $str1 is greater than
+   *   $str2, and 0 if they are equal.
+   */
+  public static function strCaseCmp($str1 , $str2) {
+    return strcmp(mb_strtoupper($str1, 'utf-8'), mb_strtoupper($str2, 'utf-8'));
+  }
+
   /**
    * Encodes MIME/HTTP headers that contain incorrectly encoded characters.
    *

core/lib/Drupal/Core/Database/Driver/sqlite/Connection.php

@@ -124,6 +124,9 @@ class Connection extends DatabaseConnection {
     $pdo->sqliteCreateFunction('rand', array(__CLASS__, 'sqlFunctionRand'));
     $pdo->sqliteCreateFunction('regexp', array(__CLASS__, 'sqlFunctionRegexp'));
 
+    // Create a user-space case-insensitive collation with UTF-8 support.
+    $pdo->sqliteCreateCollation('NOCASE_UTF8', array('Drupal\Component\Utility\Unicode', 'strCaseCmp'));
+
     // Execute sqlite init_commands.
     if (isset($connection_options['init_commands'])) {
       $pdo->exec(implode('; ', $connection_options['init_commands']));

core/lib/Drupal/Core/Database/Driver/sqlite/Schema.php

@@ -160,8 +160,14 @@ class Schema extends DatabaseSchema {
     else {
       $sql = $name . ' ' . $spec['sqlite_type'];
 
-      if (in_array($spec['sqlite_type'], array('VARCHAR', 'TEXT')) && isset($spec['length'])) {
+      if (in_array($spec['sqlite_type'], array('VARCHAR', 'TEXT'))) {
-        $sql .= '(' . $spec['length'] . ')';
+        if (isset($spec['length'])) {
+          $sql .= '(' . $spec['length'] . ')';
+        }
+
+        if (isset($spec['binary']) && $spec['binary'] === FALSE) {
+          $sql .= ' COLLATE NOCASE_UTF8';
+        }
       }
 
       if (isset($spec['not null'])) {