simplify seek/read check

backend/os/file.go

@@ -457,7 +457,7 @@ func (f *File) copyToLocalTempReader() (*os.File, error) {
 	// So imagine we have a file with content "hello world" and we call Seek(6, 0) and then Write([]byte("there")), the
 	// temp file should have "hello there" and not "there".  Then finally when Close is called, the temp file is renamed
 	// to the original file.  This code ensures that scenario works as expected.
-	if exists {
+	if exists && (f.seekCalled || f.readCalled) {
 		openFunc := openOSFile
 		if f.fileOpener != nil {
 			openFunc = f.fileOpener
@@ -467,10 +467,8 @@ func (f *File) copyToLocalTempReader() (*os.File, error) {
 		if err != nil {
 			return nil, err
 		}
-		if f.seekCalled || f.readCalled {
-			if _, err := io.Copy(tmpFile, actualFile); err != nil {
-				return nil, err
-			}
+		if _, err := io.Copy(tmpFile, actualFile); err != nil {
+			return nil, err
 		}
 
 		if f.cursorPos > 0 {