PHP debugger does not display content of long string

PHP debugger does not display content of variable if it contains string longer than maximum data length set in PHP debugging options.

Steps to reproduce:

1. In PHP file create variable with long content like $longString = str_repeat('A', 3000);
2. Verify that Maximum Data Length setting is set to lower value than length of $longString
3. Run debugger and step over previous statement.
4. Open Variables tab.

Expected result - content of $longString will be displayed - "AAAAAA....".
Actual result - "Evaluating..." is displayed as content of $longString