Asterisks in text with block linking: no match found

The matching algorithm for block linking (^) doesn’t handle asterisks well. This makes it difficult to copy-and-paste text into new block links.

For example, if you have this paragraph:

I did a good deed. **Ann had a book in bed.** Dan ran down Gill Hill.

Copy it, and then paste it into a new block link: No match is found.

But remove the first pair of asterisks, and the match is found:

I don’t see this as bug.