Merge pull request #1107 from MJegorovas/fixNSDataToByteString

Fix 'NSData.toByteString'

Author: oldergod

okio/src/appleMain/kotlin/okio/ByteString.kt

@@ -22,11 +22,16 @@ import platform.posix.memcpy
 
 fun NSData.toByteString(): ByteString {
   val data = this
-  return ByteString(
-    ByteArray(data.length.toInt()).apply {
-      usePinned { pinned ->
-        memcpy(pinned.addressOf(0), data.bytes, data.length)
+  val size = data.length.toInt()
+  return if (size != 0) {
+    ByteString(
+      ByteArray(size).apply {
+        usePinned { pinned ->
+          memcpy(pinned.addressOf(0), data.bytes, data.length)
+        }
       }
-    }
-  )
+    )
+  } else {
+    ByteString.EMPTY
+  }
 }

okio/src/appleTest/kotlin/okio/AppleByteStringTest.kt

@@ -28,4 +28,10 @@ class AppleByteStringTest {
     val byteString = data.toByteString()
     assertEquals("Hello", byteString.utf8())
   }
+
+  @Test fun emptyNsDataToByteString() {
+    val data = ("" as NSString).dataUsingEncoding(NSUTF8StringEncoding) as NSData
+    val byteString = data.toByteString()
+    assertEquals(ByteString.EMPTY, byteString)
+  }
 }