From a68e6cd3d73680282d06e2d7676f0bca3056c71b Mon Sep 17 00:00:00 2001
From: Jimmi Holst Christensen <jhc@dismail.de>
Date: Fri, 7 Jan 2022 18:57:39 +0100
Subject: [PATCH] Return Value.zero when the result of shr requires zero bits

---
 src/value.zig | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/value.zig b/src/value.zig
index 9da9fa6307..c4d35ad006 100644
--- a/src/value.zig
+++ b/src/value.zig
@@ -2635,9 +2635,17 @@ pub const Value = extern union {
         var lhs_space: Value.BigIntSpace = undefined;
         const lhs_bigint = lhs.toBigInt(&lhs_space);
         const shift = @intCast(usize, rhs.toUnsignedInt());
+
+        const result_limbs = lhs_bigint.limbs.len -| (shift / (@sizeOf(std.math.big.Limb) * 8));
+        if (result_limbs == 0) {
+            // The shift is enough to remove all the bits from the number, which means the
+            // result is zero.
+            return Value.zero;
+        }
+
         const limbs = try allocator.alloc(
             std.math.big.Limb,
-            lhs_bigint.limbs.len - (shift / (@sizeOf(std.math.big.Limb) * 8)),
+            result_limbs,
         );
         var result_bigint = BigIntMutable{
             .limbs = limbs,