ext/bcmath: Fixed bcdiv() div by one (#15629)

Fixed the incorrect scale that should be used when dividing by 1, that is,
comparing the divisor and 1 to confirm equality.

Additionally, have increased the number of test cases for bcdiv_by_pow_10.phpt.

Author: SakiTakamachi

ext/bcmath/libbcmath/src/div.c

@@ -344,7 +344,7 @@ bool bc_divide(bc_num numerator, bc_num divisor, bc_num *quot, size_t scale)
 	}
 
 	/* If divisor is 1 / -1, the quotient's n_value is equal to numerator's n_value. */
-	if (_bc_do_compare(divisor, BCG(_one_), scale, false) == BCMATH_EQUAL) {
+	if (_bc_do_compare(divisor, BCG(_one_), divisor->n_scale, false) == BCMATH_EQUAL) {
 		size_t quot_scale = MIN(numerator->n_scale, scale);
 		*quot = bc_new_num_nonzeroed(numerator->n_len, quot_scale);
 		char *qptr = (*quot)->n_value;

ext/bcmath/tests/bcdiv_by_one.phpt

@@ -0,0 +1,98 @@
+--TEST--
+bcdiv() function div by one
+--EXTENSIONS--
+bcmath
+--INI--
+bcmath.scale=0
+--FILE--
+<?php
+$dividend_cases = ['100', '-100'];
+$divisor_cases = ['1.010', '1.01', '1.1', '1', '-1.010', '-1.01', '-1.1', '-1'];
+$scale_cases = [0, 1, 2, 3];
+
+foreach ($scale_cases as $scale) {
+    echo "scale: {$scale}\n";
+    foreach ($divisor_cases as $divisor) {
+        foreach ($dividend_cases as $dividend) {
+            $dividend_label = str_pad($dividend, 4, ' ', STR_PAD_LEFT);
+            $divisor_label = str_pad($divisor, 6, ' ', STR_PAD_LEFT);
+            $quot = bcdiv($dividend, $divisor, $scale);
+            $quot_label = str_pad($quot, $scale + 2 + ($scale ? 1 : 0), ' ', STR_PAD_LEFT);
+            echo $dividend_label, ' / ', $divisor_label, ' = ', $quot_label, "\n";
+        }
+    }
+    echo "\n";
+}
+?>
+--EXPECT--
+scale: 0
+ 100 /  1.010 = 99
+-100 /  1.010 = -99
+ 100 /   1.01 = 99
+-100 /   1.01 = -99
+ 100 /    1.1 = 90
+-100 /    1.1 = -90
+ 100 /      1 = 100
+-100 /      1 = -100
+ 100 / -1.010 = -99
+-100 / -1.010 = 99
+ 100 /  -1.01 = -99
+-100 /  -1.01 = 99
+ 100 /   -1.1 = -90
+-100 /   -1.1 = 90
+ 100 /     -1 = -100
+-100 /     -1 = 100
+
+scale: 1
+ 100 /  1.010 = 99.0
+-100 /  1.010 = -99.0
+ 100 /   1.01 = 99.0
+-100 /   1.01 = -99.0
+ 100 /    1.1 = 90.9
+-100 /    1.1 = -90.9
+ 100 /      1 = 100.0
+-100 /      1 = -100.0
+ 100 / -1.010 = -99.0
+-100 / -1.010 = 99.0
+ 100 /  -1.01 = -99.0
+-100 /  -1.01 = 99.0
+ 100 /   -1.1 = -90.9
+-100 /   -1.1 = 90.9
+ 100 /     -1 = -100.0
+-100 /     -1 = 100.0
+
+scale: 2
+ 100 /  1.010 = 99.00
+-100 /  1.010 = -99.00
+ 100 /   1.01 = 99.00
+-100 /   1.01 = -99.00
+ 100 /    1.1 = 90.90
+-100 /    1.1 = -90.90
+ 100 /      1 = 100.00
+-100 /      1 = -100.00
+ 100 / -1.010 = -99.00
+-100 / -1.010 = 99.00
+ 100 /  -1.01 = -99.00
+-100 /  -1.01 = 99.00
+ 100 /   -1.1 = -90.90
+-100 /   -1.1 = 90.90
+ 100 /     -1 = -100.00
+-100 /     -1 = 100.00
+
+scale: 3
+ 100 /  1.010 = 99.009
+-100 /  1.010 = -99.009
+ 100 /   1.01 = 99.009
+-100 /   1.01 = -99.009
+ 100 /    1.1 = 90.909
+-100 /    1.1 = -90.909
+ 100 /      1 = 100.000
+-100 /      1 = -100.000
+ 100 / -1.010 = -99.009
+-100 / -1.010 = 99.009
+ 100 /  -1.01 = -99.009
+-100 /  -1.01 = 99.009
+ 100 /   -1.1 = -90.909
+-100 /   -1.1 = 90.909
+ 100 /     -1 = -100.000
+-100 /     -1 = 100.000