Proper initialization of $_message variable according to value of $result

While calling getDisplay, $_message should be an instance of PMA\libraries\Message.

Fix #12650

Also, spaces at the beginning of a table name are allowed if used inside backquotes.

Signed-off-by: Deven Bansod <devenbansod.bits@gmail.com>

libraries/Table.php

@@ -1245,17 +1245,22 @@ class Table
      * checks if given name is a valid table name,
      * currently if not empty, trailing spaces, '.', '/' and '\'
      *
-     * @param string $table_name name to check
+     * @param string  $table_name    name to check
+     * @param boolean $is_backquoted whether this name is used inside backquotes or not
      *
      * @todo add check for valid chars in filename on current system/os
      * @see  https://dev.mysql.com/doc/refman/5.0/en/legal-names.html
      *
      * @return boolean whether the string is valid or not
      */
-    static function isValidName($table_name)
+    static function isValidName($table_name, $is_backquoted = false)
     {
-        if ($table_name !== trim($table_name)) {
-            // trailing spaces
+        if ($table_name !== rtrim($table_name)) {
+            // trailing spaces not allowed even in backquotes
+            return false;
+        }
+        if (! $is_backquoted && $table_name !== trim($table_name)) {
+            // spaces at the start or in between
             return false;
         }
 
@@ -1310,7 +1315,10 @@ class Table
             return true;
         }
 
-        if (! Table::isValidName($new_name)) {
+        // Allow whitespaces (not trailing) in $new_name,
+        // since we are using $backquoted in getting the fullName of table
+        // below to be used in the query
+        if (! Table::isValidName($new_name, true)) {
             $this->errors[] = __('Invalid table name:') . ' '
                 . $new_table->getFullName();
             return false;

tbl_operations.php

@@ -226,7 +226,12 @@ if (isset($result) && empty($message_to_show)) {
             }
             exit;
         }
+    } else {
+        $_message = $result
+            ? PMA\libraries\Message::success($_message)
+            : PMA\libraries\Message::error($_message);
     }
+
     if (! empty($warning_messages)) {
         $_message = new PMA\libraries\Message;
         $_message->addMessages($warning_messages);