Clarify "is negative zero" check

RenderMichael · RenderMichael · commit 98cafd1bd834 · 2025-03-11T16:37:58.000-04:00
diff --git a/dotnet/src/webdriver/BiDi/Communication/Json/Converters/BiDiDoubleConverter.cs b/dotnet/src/webdriver/BiDi/Communication/Json/Converters/BiDiDoubleConverter.cs
@@ -83,9 +83,10 @@ public override void Write(Utf8JsonWriter writer, double value, JsonSerializerOp
 
             static bool IsNegativeZero(double x)
             {
-                const long NegativeZeroBits = -9223372036854775808;
+                // Negative zero is less trivial to test, because 0 == -0 is true
+                // We need to do a bit pattern comparison
 
-                return BitConverter.DoubleToInt64Bits(x) == NegativeZeroBits;
+                return BitConverter.DoubleToInt64Bits(x) == BitConverter.DoubleToInt64Bits(-0.0);
             }
         }
     }

Original file line number	Diff line number	Diff line change
`@@ -83,9 +83,10 @@ public override void Write(Utf8JsonWriter writer, double value, JsonSerializerOp`
`83`	`83`
`84`	`84`	`static bool IsNegativeZero(double x)`
`85`	`85`	`{`
`86`		`- const long NegativeZeroBits = -9223372036854775808;`
	`86`	`+ // Negative zero is less trivial to test, because 0 == -0 is true`
	`87`	`+ // We need to do a bit pattern comparison`
`87`	`88`
`88`		`- return BitConverter.DoubleToInt64Bits(x) == NegativeZeroBits;`
	`89`	`+ return BitConverter.DoubleToInt64Bits(x) == BitConverter.DoubleToInt64Bits(-0.0);`
`89`	`90`	`}`
`90`	`91`	`}`
`91`	`92`	`}`