Support for io.EOF to C.AVERROR_EOF mapping (#73)

* Support for io.EOF to C.AVERROR_EOF mapping

* Requested changes

io_context.go

@@ -6,6 +6,7 @@ import "C"
 import (
 	"errors"
 	"fmt"
+	"io"
 	"sync"
 	"unsafe"
 )
@@ -241,6 +242,8 @@ func goAstiavIOContextReadFunc(opaque unsafe.Pointer, buf *C.uint8_t, bufSize C.
 		var e Error
 		if errors.As(err, &e) {
 			return C.int(e)
+		} else if errors.Is(err, io.EOF) {
+			return C.AVERROR_EOF
 		}
 		return C.AVERROR_UNKNOWN
 	}

io_context_test.go

@@ -1,6 +1,7 @@
 package astiav
 
 import (
+	"io"
 	"os"
 	"path/filepath"
 	"testing"
@@ -9,6 +10,7 @@ import (
 )
 
 func TestIOContext(t *testing.T) {
+	t.Run("read write seek", func(t *testing.T) {
 		var seeked bool
 		rb := []byte("read")
 		wb := []byte("write")
@@ -37,6 +39,19 @@ func TestIOContext(t *testing.T) {
 		c.Write(wb)
 		c.Flush()
 		require.Equal(t, wb, written)
+	})
+
+	t.Run("io.EOF is mapped to AVERROR_EOF when reading", func(t *testing.T) {
+		c, err := AllocIOContext(8, false, func(b []byte) (int, error) {
+			return 0, io.EOF
+		}, nil, nil)
+		require.NoError(t, err)
+		defer c.Free()
+		b := make([]byte, 100)
+		n, err := c.Read(b)
+		require.ErrorIs(t, err, ErrEof)
+		require.Equal(t, 0, n)
+	})
 }
 
 func TestOpenIOContext(t *testing.T) {