Fixed issue when using CipherSource and fully relying on it reporting…

… -1 only if nothing was written to the Sink.

This was happening when using Okio's BufferedSource which short-cuts reading even if bytes were written to the wrapped Buffer. A test was added to capture the bug.

lib/src/main/java/nl/nl2312/okio/cipher/CipherSource.kt

@@ -53,8 +53,8 @@ class CipherSource(
  val bytesToReturn = bytesRequested.coerceAtMost(decipheredBuffer.size())
  sink.write(decipheredBuffer, bytesToReturn)
 
- // Return number of written deciphered bytes, or -1 if the source stream is exhausted and our buffer is empty
- return if (streamEnd && decipheredBuffer.size() == 0L) -1 else bytesToReturn
+ // Return number of written deciphered bytes, or -1 if there is nothing more to decipher
+ return if (bytesToReturn > 0) bytesToReturn else -1
  }
 
 }

lib/src/test/java/nl/nl2312/okio/cipher/CipherSourceTest.kt

@@ -4,6 +4,8 @@ import com.google.common.truth.Truth.assertThat
 import nl.nl2312.okio.base64.Base64Source
 import okio.Buffer
 import okio.ByteString
+import okio.Okio
+import okio.Source
 import org.junit.Test
 import java.security.SecureRandom
 import javax.crypto.Cipher
@@ -104,6 +106,21 @@ class CipherSourceTest {
  assertThat(output.readUtf8()).isEqualTo("okio oh my¿¡ okio oh my¿¡ okio oh my¿¡")
  }
 
+ @Test
+ fun read_buffered_whileBytesRead() {
+ val ciphered = encodeCipher.doFinal("okio oh my¿¡ okio oh my¿¡ okio oh my¿¡".toByteArray())
+ val cipheredSource = Buffer().write(ciphered)
+
+ val decoded = CipherSource(cipheredSource, decodeCipher)
+
+ // Okio's RealBufferedSource.read(Buffer, Long) will only write to the given buffer when the
+ // CipherSource.read(Buffer, Long) returns a non-negative byes read could
+ val buffer = Okio.buffer(decoded as Source)
+ val output = Buffer()
+ buffer.read(output, 8192)
+ assertThat(output.readUtf8()).isEqualTo("okio oh my¿¡ okio oh my¿¡ okio oh my¿¡")
+ }
+
  @Test
  fun read_base64Wrapped() {
  val ciphered = encodeCipher.doFinal("okio oh my¿¡".toByteArray())