GH-34807: [Go] Handle io.EOF when reading parquet footer size and magic bytes

go/parquet/file/file_reader.go

@@ -163,7 +163,7 @@ func (f *Reader) parseMetaData() error {
 	buf := make([]byte, footerSize)
 	// backup 8 bytes to read the footer size (first four bytes) and the magic bytes (last 4 bytes)
 	n, err := f.r.ReadAt(buf, f.footerOffset-int64(footerSize))
-	if err != nil {
+	if err != nil && err != io.EOF {
 		return fmt.Errorf("parquet: could not read footer: %w", err)
 	}
 	if n != len(buf) {

go/parquet/file/file_reader_test.go

@@ -25,14 +25,17 @@ import (
 
 	"github.com/apache/arrow/go/v12/arrow/memory"
 	"github.com/apache/arrow/go/v12/internal/utils"
+	"github.com/apache/arrow/go/v12/parquet"
 	"github.com/apache/arrow/go/v12/parquet/compress"
 	"github.com/apache/arrow/go/v12/parquet/file"
 	"github.com/apache/arrow/go/v12/parquet/internal/encoding"
 	format "github.com/apache/arrow/go/v12/parquet/internal/gen-go/parquet"
 	"github.com/apache/arrow/go/v12/parquet/internal/thrift"
 	"github.com/apache/arrow/go/v12/parquet/metadata"
+	"github.com/apache/arrow/go/v12/parquet/schema"
 	libthrift "github.com/apache/thrift/lib/go/thrift"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 )
 
@@ -65,6 +68,19 @@ func checkStatistics(t *testing.T, stats format.Statistics, actual metadata.Enco
 	}
 }
 
+type testReader struct {
+	*bytes.Reader
+}
+
+// ReadAt for testReader returns io.EOF when off + len(b) is exactly the length of the underlying input source.
+func (tr testReader) ReadAt(b []byte, off int64) (int, error) {
+	n, err := tr.Reader.ReadAt(b, off)
+	if err == nil && (int64(n)+off == tr.Size()) {
+		return n, io.EOF
+	}
+	return n, err
+}
+
 type PageSerdeSuite struct {
 	suite.Suite
 
@@ -271,6 +287,20 @@ func (p *PageSerdeSuite) TestCompression() {
 	}
 }
 
+func TestWithEOFReader(t *testing.T) {
+	root, _ := schema.NewGroupNode("schema", parquet.Repetitions.Repeated, schema.FieldList{
+		schema.NewInt32Node("int_col", parquet.Repetitions.Required, -1)}, -1)
+	props := parquet.NewWriterProperties(parquet.WithVersion(parquet.V2_LATEST))
+
+	var buf bytes.Buffer
+	wr := file.NewParquetWriter(&buf, root, file.WithWriterProps(props))
+	require.NoError(t, wr.Close())
+
+	r := bytes.NewReader(buf.Bytes())
+	_, err := file.NewParquetReader(testReader{Reader: r})
+	assert.NoError(t, err)
+}
+
 func TestInvalidHeaders(t *testing.T) {
 	badHeader := []byte("PAR2")
 	_, err := file.NewParquetReader(bytes.NewReader(badHeader))