Merge branch 'fix_compare_bug' into 'main'

Fix bug: compare with zero

See merge request codbase/decimal-rs!9

benches/benchmark.rs

@@ -155,6 +155,14 @@ fn decimal_hash(bench: &mut Bencher) {
     })
 }
 
+fn decimal_cmp(bench: &mut Bencher) {
+    let x = parse("12345678901.23456789");
+    let y = parse("12345.67890123456789");
+    bench.iter(|| {
+        let _n = black_box(x > y);
+    })
+}
+
 benchmark_group!(
     decimal_benches,
     decimal_parse,
@@ -171,6 +179,7 @@ benchmark_group!(
     decimal_decode,
     decimal_normalize,
     decimal_hash,
+    decimal_cmp,
 );
 
 benchmark_main!(decimal_benches);

src/decimal.rs

@@ -785,6 +785,16 @@ impl Ord for Decimal {
             (self, other)
         };
 
+        if left.is_zero() {
+            return if right.is_zero() {
+                Ordering::Equal
+            } else {
+                Ordering::Less
+            };
+        } else if right.is_zero() {
+            return Ordering::Greater;
+        }
+
         if left.scale == right.scale {
             // fast path for same scale
             return left.int_val.cmp(&right.int_val);
@@ -967,6 +977,14 @@ mod tests {
         assert_cmp!(
             "-9.9999999999999999999999999999999999999", <, "1"
         );
+        assert_cmp!("4703178999618078116505370421100e39", >, "0");
+        assert_cmp!("4703178999618078116505370421100e-39", >, "0");
+        assert_cmp!("-4703178999618078116505370421100e39", <, "0");
+        assert_cmp!("-4703178999618078116505370421100e-39", <, "0");
+        assert_cmp!("0", <, "4703178999618078116505370421100e39");
+        assert_cmp!("0", <, "4703178999618078116505370421100e-39");
+        assert_cmp!("0", >, "-4703178999618078116505370421100e39");
+        assert_cmp!("0", >, "-4703178999618078116505370421100e-39");
     }
 
     #[test]