Fix issue 22771 - BigInt divMod can return "-0" (negative zero)

dlang · Feb 14, 2022 · 1e30d05 · 1e30d05
1 parent 2629671
commit 1e30d05
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/std/bigint.d b/std/bigint.d
@@ -2244,7 +2244,7 @@ void divMod(const BigInt dividend, const BigInt divisor, out BigInt quotient, ou
     BigUint.divMod(dividend.data, divisor.data, q, r);
     quotient.sign = dividend.sign != divisor.sign;
     quotient.data = q;
-    remainder.sign = dividend.sign;
+    remainder.sign = r.isZero() ? false : dividend.sign;
     remainder.data = r;
 }
 
@@ -2291,6 +2291,14 @@ void divMod(const BigInt dividend, const BigInt divisor, out BigInt quotient, ou
     assert(q * d + r == -c);
 }
 
+// https://issues.dlang.org/show_bug.cgi?id=22771
+@safe pure nothrow unittest
+{
+    BigInt quotient, remainder;
+    divMod(BigInt(-50), BigInt(1), quotient, remainder);
+    assert(remainder == 0);
+}
+
 // https://issues.dlang.org/show_bug.cgi?id=19740
 @safe unittest
 {