When repr(obj) contains a newline character, an extra blank line is inserted.

[stakemori]

In Sage 7.4, if repr(obj) contains a newline character, an extra blank line is inserted. One can reproduce this in Sage in the terminal, e.g.

sage: matrix(QQ, 2)

[0 0]
[0 0]

[EmmanuelCharpentier]

I saw your recent update, and installed it. We're almost there, as shown by this screenshot :

the superfluous blank line still exists for matrix output, bu has disappeared from typeset output (and plots).

HTH,