bug #1859460, prevent an empty target_db field to produce a failure, thanks to windkiel

tbl_move_copy.php

@@ -26,6 +26,14 @@ $err_url = 'tbl_sql.php?' . PMA_generate_common_url($db, $table);
  */
 PMA_DBI_select_db($db);
 
+/** 
+ * $target_db could be empty in case we came from an input field 
+ * (when there are many databases, no drop-down)
+ */
+if (empty($target_db)) {
+    $target_db = $db;
+}
+
 /**
  * A target table name has been sent to this script -> do the work
  */

tbl_operations.php

@@ -190,7 +190,7 @@ unset($columns);
     <legend><?php echo $strMoveTable; ?></legend>
 <?php if ($GLOBALS['PMA_List_Database']->count() > $GLOBALS['cfg']['MaxDbList']) {
 ?>
-    <input type="text" maxlength="100" size="30" name="target_db" />
+    <input type="text" maxlength="100" size="30" name="target_db" value="<?php echo htmlspecialchars($GLOBALS['db']); ?>"/>
 <?php
     } else {
 ?>
@@ -353,7 +353,7 @@ if (isset($auto_increment) && strlen($auto_increment) > 0
     <legend><?php echo $strCopyTable; ?></legend>
 <?php if ($GLOBALS['PMA_List_Database']->count() > $GLOBALS['cfg']['MaxDbList']) {
 ?>
-    <input type="text" maxlength="100" size="30" name="target_db" />
+    <input type="text" maxlength="100" size="30" name="target_db" value="<?php echo htmlspecialchars($GLOBALS['db']); ?>"/>
 <?php
     } else {
 ?>