Improved handling of adjusting result digits

Author: SakiTakamachi

ext/standard/math.c

@@ -148,9 +148,9 @@ PHPAPI double _php_math_round(double value, int places, int mode) {
 		} else {
 			tmp_value = value / f2;
 		}
-		/* preround the result (tmp_value will always be something * 1e14,
+		/* adjust result digits (tmp_value will always be something * 1e14,
 		   thus never larger than 1e15 here) */
-		tmp_value = php_round_helper(tmp_value, mode);
+		tmp_value = (tmp_value >= 0.0) ? floor(tmp_value) : ceil(tmp_value);
 
 		use_precision = places - precision_places;
 		use_precision = use_precision < INT_MIN+1 ? INT_MIN+1 : use_precision;

ext/standard/tests/math/round_gh12143_adjustment_result_digit.phpt

@@ -0,0 +1,10 @@
+--TEST--
+Fix GH-12143: Improved handling of adjusting result digits
+--FILE--
+<?php
+var_dump(round(1.700000000000145, 13, PHP_ROUND_HALF_UP));
+var_dump(round(-1.700000000000145, 13, PHP_ROUND_HALF_UP));
+?>
+--EXPECT--
+float(1.7000000000001)
+float(-1.7000000000001)