There appears to be a memory leak when setting a property value of a COM object in 4.2.3.  Running under ISAPI if this script is repeated memory usage continues to grow:

$adodb = new COM("ADODB.Connection");
$adodb->ConnectionString = str_repeat("this is a text string!", 1000);

Looking through the patches that have been applied, I believe that this is caused when COM.c went from 1.78 to 1.79 (which was then back-ported to 4.2.3).  In this patch at the end of do_COM_propput(), this:

FREE_VARIANT(new_value);

became this:

efree(new_value); // FREE_VARIANT does a VariantClear() which is not desired here !

If I reverse this patch I no longer see the leak and the code still appears to be working correctly.  What was the purpose of this change?  Does doing the FREE_VARIANT version cause some other issue?