Scale support for bcmod()

As of commit 90dcbbe (PHP-7.2+) bcmod() supports non-integral parameters as well. Since formerly only integer modulus has been supported, it did not make much sense to cater to the scale with regard to the result. However, now it does for consistency with other BCMath operations. Therefore, we add support for an optional `scale` parameter and fall back to the default scale (`bcmath.scale`) as usual.
php · Nov 6, 2017 · b152633 · b152633
1 parent 5cdf37e
commit b152633
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Showing 3 changed files with 21 additions and 8 deletions.
diff --git a/ext/bcmath/bcmath.c b/ext/bcmath/bcmath.c
@@ -60,9 +60,10 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_bcdiv, 0, 0, 2)
 	ZEND_ARG_INFO(0, scale)
 ZEND_END_ARG_INFO()
 
-ZEND_BEGIN_ARG_INFO(arginfo_bcmod, 0)
+ZEND_BEGIN_ARG_INFO_EX(arginfo_bcmod, 0, 0, 2)
 	ZEND_ARG_INFO(0, left_operand)
 	ZEND_ARG_INFO(0, right_operand)
+	ZEND_ARG_INFO(0, scale)
 ZEND_END_ARG_INFO()
 
 ZEND_BEGIN_ARG_INFO_EX(arginfo_bcpowmod, 0, 0, 3)
@@ -388,26 +389,38 @@ PHP_FUNCTION(bcdiv)
 }
 /* }}} */
 
-/* {{{ proto string bcmod(string left_operand, string right_operand)
+/* {{{ proto string bcmod(string left_operand, string right_operand [, int scale])
    Returns the modulus of the two arbitrary precision operands */
 PHP_FUNCTION(bcmod)
 {
 	zend_string *left, *right;
+	zend_long scale_param = 0;
 	bc_num first, second, result;
+	int scale = (int)BCG(bc_precision);
 
-	ZEND_PARSE_PARAMETERS_START(2, 2)
+	ZEND_PARSE_PARAMETERS_START(2, 3)
 		Z_PARAM_STR(left)
 		Z_PARAM_STR(right)
+		Z_PARAM_OPTIONAL
+		Z_PARAM_LONG(scale_param)
 	ZEND_PARSE_PARAMETERS_END();
 
+	if (ZEND_NUM_ARGS() == 3) {
+		scale = (int) ((int)scale_param < 0 ? 0 : scale_param);
+	}
+
 	bc_init_num(&first);
 	bc_init_num(&second);
 	bc_init_num(&result);
 	php_str2num(&first, ZSTR_VAL(left));
 	php_str2num(&second, ZSTR_VAL(right));
 
-	switch (bc_modulo(first, second, &result, 0)) {
+	switch (bc_modulo(first, second, &result, scale)) {
 		case 0:
+			if (result->n_scale > scale) {
+				result = split_bc_num(result);
+				result->n_scale = scale;
+			}
 			RETVAL_STR(bc_num2str(result));
 			break;
 		case -1:

diff --git a/ext/bcmath/tests/bcmod.phpt b/ext/bcmath/tests/bcmod.phpt
@@ -9,12 +9,12 @@ bcmath.scale=0
 echo bcmod("11", "2"),"\n";
 echo bcmod("-1", "5"),"\n";
 echo bcmod("8728932001983192837219398127471", "1928372132132819737213"),"\n";
-echo bcmod("3.5", "4"),"\n";
+echo bcmod("3.5", "4", 1),"\n";
 echo bcmod("1071", "357.5"),"\n";
 ?>
 --EXPECT--
 1
 -1
 1459434331351930289678
 3.5
-356.0
+356
diff --git a/ext/bcmath/tests/bcmod_error1.phpt b/ext/bcmath/tests/bcmod_error1.phpt
@@ -7,7 +7,7 @@ antoni@solucionsinternet.com
 <?php if(!extension_loaded("bcmath")) print "skip"; ?>
 --FILE--
 <?php
-echo bcmod('1', '2', '3');
+echo bcmod('1', '2', '3', '4');
 ?>
 --EXPECTF--
-Warning: bcmod() expects exactly 2 parameters, 3 given in %s.php on line %d
+Warning: bcmod() expects at most 3 parameters, 4 given in %s.php on line %d