Copy (highlight) text inside CodeBox with LEFT SHIFT in not working

[AlexeiKlimenko]

Version, Operating system State the Version and the Operating System/Desktop. Try the latest available version before reporting an issue. 0.99.43 Linux Mint

Describe the bug A clear and concise description of what the bug is. You can afford to copy a block of text with using LEFT SHIFT inside the node, but it doesn't work properly inside CodeBox.

To Reproduce Add CodeBox, put a block of text inside Codebox and try to copy text with LEFT SHIFT inside code box - it will not be highlighted for copying.