Remove instances of LOWERE casing searches from sort_name, display_name.

Per civicrm#12494 mysql handles lcase.

Adding LOWER to mysql queries makes them slower. lowercasing php strings
breaks under some character sets with some server configs. Less is more

CRM/Contact/BAO/Query.php

@@ -3402,8 +3402,6 @@ public function sortName(&$values) {
     //By default, $sub elements should be joined together with OR statements (don't change this variable).
     $subGlue = ' OR ';
 
-    $strtolower = function_exists('mb_strtolower') ? 'mb_strtolower' : 'strtolower';
-
     $firstChar = substr($value, 0, 1);
     $lastChar = substr($value, -1, 1);
     $quotes = array("'", '"');
@@ -3416,22 +3414,19 @@ public function sortName(&$values) {
     elseif ($op == 'LIKE' && strpos($value, ',') === FALSE) {
       $value = str_replace(' ', '%', $value);
     }
-    $value = $strtolower(CRM_Core_DAO::escapeString(trim($value)));
+    $value = CRM_Core_DAO::escapeString(trim($value));
     if (strlen($value)) {
       $fieldsub = array();
       $value = "'" . self::getWildCardedValue($wildcard, $op, $value) . "'";
       if ($fieldName == 'sort_name') {
-        // LOWER roughly translates to 'hurt my database without deriving any benefit' See CRM-19811.
-        $wc = self::caseImportant($op) ? "LOWER(contact_a.sort_name)" : "contact_a.sort_name";
+        $wc = "contact_a.sort_name";
       }
       else {
-        // LOWER roughly translates to 'hurt my database without deriving any benefit' See CRM-19811.
-        $wc = self::caseImportant($op) ? "LOWER(contact_a.display_name)" : "contact_a.display_name";
+        $wc = "contact_a.display_name";
       }
       $fieldsub[] = " ( $wc $op $value )";
       if ($config->includeNickNameInName) {
-        // LOWER roughly translates to 'hurt my database without deriving any benefit' See CRM-19811.
-        $wc = self::caseImportant($op) ? "LOWER(contact_a.nick_name)" : "contact_a.nick_name";
+        $wc = "contact_a.nick_name";
         $fieldsub[] = " ( $wc $op $value )";
       }
       if ($config->includeEmailInName) {

tests/phpunit/api/v3/ContactTest.php

@@ -396,6 +396,22 @@ public function testCreateDisplayNameIndividual() {
     $this->getAndCheck($params, $contact['id'], 'contact');
   }
 
+  /**
+   * Test that name searches are case insensitive.
+   */
+  public function testGetNameVariantsCaseInsensitive() {
+    $this->callAPISuccess('contact', 'create', [
+      'display_name' => 'Abc1',
+      'contact_type' => 'Individual',
+    ]);
+    $this->callAPISuccessGetSingle('Contact', ['display_name' => 'aBc1']);
+    $this->callAPISuccessGetSingle('Contact', ['sort_name' => 'aBc1']);
+    Civi::settings()->set('includeNickNameInName', TRUE);
+    $this->callAPISuccessGetSingle('Contact', ['display_name' => 'aBc1']);
+    $this->callAPISuccessGetSingle('Contact', ['sort_name' => 'aBc1']);
+    Civi::settings()->set('includeNickNameInName', FALSE);
+  }
+
   /**
    * Test old keys still work.
    *
@@ -3183,7 +3199,7 @@ public function testReturnCityProfile() {
    * CRM-15443 - ensure getlist api does not return deleted contacts.
    */
   public function testGetlistExcludeConditions() {
-    $name = md5(time());
+    $name = 'Scarabée';
     $contact = $this->individualCreate(array('last_name' => $name));
     $this->individualCreate(array('last_name' => $name, 'is_deceased' => 1));
     $this->individualCreate(array('last_name' => $name, 'is_deleted' => 1));