Fix _php_math_round UB

php_intlog10abs() is ill-defined for a zero value. Avoid calling it
altogether as there's nothing to round with a zero value.

diff --git a/ext/standard/math.c b/ext/standard/math.c
index 840df9103e631c66629914f4a0f4005a3c3da5b4..5172bbbd6e62d48ad211e4a9c45f918bf03cb483 100644 (file)
--- a/ext/standard/math.c
+++ b/ext/standard/math.c
@@ -129,7 +129,7 @@ PHPAPI double _php_math_round(double value, int places, int mode) {
        double tmp_value;
        int precision_places;
 
-       if (!zend_finite(value)) {
+       if (!zend_finite(value) || value == 0.0) {
                return value;
        }