fix: return EOF when buffer is empty

internal/bra/reader.go

@@ -43,6 +43,10 @@ func (rc *readCloser) Read(p []byte) (int, error) {
 			return 0, fmt.Errorf("bra: error buffering: %w", err)
 		}
 
+		if rc.buf.Len() == 0 { // Buffer is empty and read closer returned EOF; no more data available
+			return 0, io.EOF
+		}
+
 		if rc.buf.Len() < rc.conv.Size() {
 			rc.n = rc.buf.Len()
 		}

reader_test.go

@@ -14,6 +14,7 @@ import (
 	"testing"
 	"testing/fstest"
 	"testing/iotest"
+	"time"
 
 	"github.com/bodgit/sevenzip"
 	"github.com/bodgit/sevenzip/internal/util"
@@ -434,6 +435,58 @@ func TestFS(t *testing.T) {
 	}
 }
 
+// TestBraRead is a separate test as the example archive cannot be added to
+// the existing test cases in TestOpenReader as it triggers an error in the
+// LZMA library which is unrelated to the bug that it is a test case for.
+// However extracting this one file is enough to demonstrate the bug and
+// validate the fix so it's here as a separate test.
+func TestBraRead(t *testing.T) {
+	t.Parallel()
+
+	eg := new(errgroup.Group)
+
+	//nolint:wrapcheck
+	eg.Go(func() (err error) {
+		r, err := sevenzip.OpenReader(filepath.Join("testdata", "pr472.7z"))
+		if err != nil {
+			return err
+		}
+
+		defer func() {
+			err = errors.Join(err, r.Close())
+		}()
+
+		file, err := r.Open("Plug 1.2/Plug 1.2.exe")
+		if err != nil {
+			return err
+		}
+
+		defer func() {
+			err = errors.Join(err, file.Close())
+		}()
+
+		if _, err = io.ReadAll(file); err != nil {
+			return err
+		}
+
+		return nil
+	})
+
+	done := make(chan error, 1)
+	go func() {
+		done <- eg.Wait()
+	}()
+
+	select {
+	case err := <-done:
+		if err != nil {
+			t.Fatal(err)
+		}
+	case <-time.After(2 * time.Second):
+		t.Fatalf("timeout waiting for reader to complete")
+	}
+}
+
 func FuzzNewReaderWithPassword(f *testing.F) {
 	b, err := os.ReadFile(filepath.Join("testdata", "copy.7z"))
 	if err != nil {