Fix writing -0.0f and -0.0 values as 0.0

Author: plokhotnyuk

jsoniter-scala-core/js/src/main/scala/com/github/plokhotnyuk/jsoniter_scala/core/JsonWriter.scala

@@ -2514,9 +2514,10 @@ final class JsonWriter private[jsoniter_scala](
   // "The Schubfach way to render doubles": https://drive.google.com/file/d/1luHhyQF9zKlM8yJ1nebU0OgVYhfC6CBN/view
   // Sources with the license are here: https://github.com/c4f7fcce9cb06515/Schubfach/blob/3c92d3c9b1fead540616c918cdfef432bca53dfa/todec/src/math/FloatToDecimal.java
   private[this] def writeFloat(x: Float): Unit = {
+    val bits = java.lang.Float.floatToIntBits(x)
     var pos = ensureBufCapacity(15)
     val buf = this.buf
-    if (x < 0.0f) {
+    if (bits < 0) {
       buf(pos) = '-'
       pos += 1
     }
@@ -2526,7 +2527,6 @@ final class JsonWriter private[jsoniter_scala](
       buf(pos + 2) = '0'
       pos += 3
     } else {
-      val bits = java.lang.Float.floatToIntBits(x)
       var e2 = (bits >> 23 & 0xFF) - 150
       var m2 = bits & 0x7FFFFF | 0x800000
       var m10, e10 = 0
@@ -2635,9 +2635,10 @@ final class JsonWriter private[jsoniter_scala](
   // "The Schubfach way to render doubles": https://drive.google.com/file/d/1luHhyQF9zKlM8yJ1nebU0OgVYhfC6CBN/view
   // Sources with the license are here: https://github.com/c4f7fcce9cb06515/Schubfach/blob/3c92d3c9b1fead540616c918cdfef432bca53dfa/todec/src/math/DoubleToDecimal.java
   private[this] def writeDouble(x: Double): Unit = {
+    val bits = java.lang.Double.doubleToLongBits(x)
     var pos = ensureBufCapacity(24)
     val buf = this.buf
-    if (x < 0.0) {
+    if (bits < 0L) {
       buf(pos) = '-'
       pos += 1
     }
@@ -2647,7 +2648,6 @@ final class JsonWriter private[jsoniter_scala](
       buf(pos + 2) = '0'
       pos += 3
     } else {
-      val bits = java.lang.Double.doubleToLongBits(x)
       var e2 = ((bits >>> 52).toInt & 0x7FF) - 1075
       var m2 = bits & 0xFFFFFFFFFFFFFL | 0x10000000000000L
       var m10 = 0L

jsoniter-scala-core/jvm/src/main/scala/com/github/plokhotnyuk/jsoniter_scala/core/JsonWriter.scala

@@ -2250,17 +2250,17 @@ final class JsonWriter private[jsoniter_scala](
   // "The Schubfach way to render doubles": https://drive.google.com/file/d/1luHhyQF9zKlM8yJ1nebU0OgVYhfC6CBN/view
   // Sources with the license are here: https://github.com/c4f7fcce9cb06515/Schubfach/blob/3c92d3c9b1fead540616c918cdfef432bca53dfa/todec/src/math/FloatToDecimal.java
   private[this] def writeFloat(x: Float): Unit = {
+    val bits = java.lang.Float.floatToRawIntBits(x)
     var pos = ensureBufCapacity(15)
     val buf = this.buf
-    if (x < 0.0f) {
+    if (bits < 0) {
       buf(pos) = '-'
       pos += 1
     }
-    if (x == 0.0f) {
+    if (bits << 1 == 0) {
       ByteArrayAccess.setInt(buf, pos, 0x302E30)
       pos += 3
     } else {
-      val bits = java.lang.Float.floatToRawIntBits(x)
       var e2 = (bits >> 23 & 0xFF) - 150
       var m2 = bits & 0x7FFFFF | 0x800000
       var m10, e10 = 0
@@ -2362,17 +2362,17 @@ final class JsonWriter private[jsoniter_scala](
   // "The Schubfach way to render doubles": https://drive.google.com/file/d/1luHhyQF9zKlM8yJ1nebU0OgVYhfC6CBN/view
   // Sources with the license are here: https://github.com/c4f7fcce9cb06515/Schubfach/blob/3c92d3c9b1fead540616c918cdfef432bca53dfa/todec/src/math/DoubleToDecimal.java
   private[this] def writeDouble(x: Double): Unit = {
+    val bits = java.lang.Double.doubleToRawLongBits(x)
     var pos = ensureBufCapacity(25) // -1.2898455142673966E-135.toString.length + 1
     val buf = this.buf
-    if (x < 0.0) {
+    if (bits < 0L) {
       buf(pos) = '-'
       pos += 1
     }
-    if (x == 0.0) {
+    if (bits << 1 == 0L) {
       ByteArrayAccess.setInt(buf, pos, 0x302E30)
       pos += 3
     } else {
-      val bits = java.lang.Double.doubleToRawLongBits(x)
       var e2 = ((bits >> 52).toInt & 0x7FF) - 1075
       var m2 = bits & 0xFFFFFFFFFFFFFL | 0x10000000000000L
       var m10 = 0L

jsoniter-scala-core/native/src/main/scala/com/github/plokhotnyuk/jsoniter_scala/core/JsonWriter.scala

@@ -2250,17 +2250,17 @@ final class JsonWriter private[jsoniter_scala](
   // "The Schubfach way to render doubles": https://drive.google.com/file/d/1luHhyQF9zKlM8yJ1nebU0OgVYhfC6CBN/view
   // Sources with the license are here: https://github.com/c4f7fcce9cb06515/Schubfach/blob/3c92d3c9b1fead540616c918cdfef432bca53dfa/todec/src/math/FloatToDecimal.java
   private[this] def writeFloat(x: Float): Unit = {
+    val bits = java.lang.Float.floatToRawIntBits(x)
     var pos = ensureBufCapacity(15)
     val buf = this.buf
-    if (x < 0.0f) {
+    if (bits < 0) {
       buf(pos) = '-'
       pos += 1
     }
-    if (x == 0.0f) {
+    if (bits << 1 == 0) {
       ByteArrayAccess.setInt(buf, pos, 0x302E30)
       pos += 3
     } else {
-      val bits = java.lang.Float.floatToRawIntBits(x)
       var e2 = (bits >> 23 & 0xFF) - 150
       var m2 = bits & 0x7FFFFF | 0x800000
       var m10, e10 = 0
@@ -2362,17 +2362,17 @@ final class JsonWriter private[jsoniter_scala](
   // "The Schubfach way to render doubles": https://drive.google.com/file/d/1luHhyQF9zKlM8yJ1nebU0OgVYhfC6CBN/view
   // Sources with the license are here: https://github.com/c4f7fcce9cb06515/Schubfach/blob/3c92d3c9b1fead540616c918cdfef432bca53dfa/todec/src/math/DoubleToDecimal.java
   private[this] def writeDouble(x: Double): Unit = {
+    val bits = java.lang.Double.doubleToRawLongBits(x)
     var pos = ensureBufCapacity(25) // -1.2898455142673966E-135.toString.length + 1
     val buf = this.buf
-    if (x < 0.0) {
+    if (bits < 0L) {
       buf(pos) = '-'
       pos += 1
     }
-    if (x == 0.0) {
+    if (bits << 1 == 0L) {
       ByteArrayAccess.setInt(buf, pos, 0x302E30)
       pos += 3
     } else {
-      val bits = java.lang.Double.doubleToRawLongBits(x)
       var e2 = ((bits >> 52).toInt & 0x7FF) - 1075
       var m2 = bits & 0xFFFFFFFFFFFFFL | 0x10000000000000L
       var m10 = 0L

jsoniter-scala-core/shared/src/test/scala/com/github/plokhotnyuk/jsoniter_scala/core/JsonWriterSpec.scala

@@ -504,7 +504,7 @@ class JsonWriterSpec extends AnyWordSpec with Matchers with ScalaCheckPropertyCh
         val s = withWriter(_.writeVal(n))
         val l = s.length
         val i = s.indexOf('.')
-        s.toFloat shouldBe n // no data loss when parsing by JVM, Native or JS Platform
+        java.lang.Float.floatToIntBits(s.toFloat) shouldBe java.lang.Float.floatToIntBits(n) // no data loss when parsing by JVM, Native or JS Platform
         l should be <= es.length + {
           if (TestUtils.isJS) {
             if (es.indexOf('.') < 0) 3 // formatting differs from JS for floats represented as whole numbers
@@ -621,7 +621,7 @@ class JsonWriterSpec extends AnyWordSpec with Matchers with ScalaCheckPropertyCh
         val s = withWriter(_.writeVal(n))
         val l = s.length
         val i = s.indexOf('.')
-        s.toDouble shouldBe n // no data loss when parsing by JVM, Native or JS Platform
+        java.lang.Double.doubleToLongBits(s.toDouble) shouldBe java.lang.Double.doubleToLongBits(n) // no data loss when parsing by JVM, Native or JS Platform
         l should be <= es.length + {
           if (TestUtils.isJS) {
             if (es.indexOf('.') < 0) 4 // formatting differs from JS for doubles represented as whole numbers