Y Axis Maximum for Bar Charts Appears to be Wrong

Starting at line 86 of civicrm/CRM/Utils/OpenFlashChart.php we have:

// calculate max scale for graph.
$yMax = max( $yValues );
if ( $mod = $yMax%(str_pad( 5, strlen($yMax)-1, 0)))

{ $yMax += str_pad( 5, strlen($yMax)-1, 0)-$mod; }

This code works fine if $yMax is set in the first line to an integer value, but if it is a decimal value, with two places (like a currency value) then the following 3 lines will reset it to be far too high. If it's 85000.23 for example, then the $yMax will come out 5000000.23. If we use this as the first line:

$yMax = round( max( $yValues ));

however, then 85000.23 is recalculated as 90000, which is correct.