Index: branches/5.2.x/core/kernel/utility/formatters/formatter.php
===================================================================
--- branches/5.2.x/core/kernel/utility/formatters/formatter.php
+++ branches/5.2.x/core/kernel/utility/formatters/formatter.php
@@ -177,6 +177,11 @@
 		}
 
 		if (isset($format) && $format) {
+			if ( substr($format, -1) === 'f' ) {
+				// High precision formats (e.g. '%01.20f') are not supported to keep code below as fast as possible.
+				$value = round($value, substr($format, -2, 1));
+			}
+
 			$value = sprintf($format, $value);
 
 			if ( isset($options['cut_zeros']) && $options['cut_zeros'] ) {