Performance problem with keyboard macros and C-n

[Robert Thorpe]

On Reddit someone pointed to a performance problem with a keyboard
macro. I investigated it a bit more and found that it was caused by an
interaction between C-n and some programming modes.

Basically, the macro is extremely slow if C-n is used to move between
lines and the macro is run in python-mode or c-mode.  However, it is
very fast if fundamental-mode is used or if forward-line is used to move
to the next line.  It is also very fast if apply-macro-to-region-lines
is used.

Is this a known performance bug, or should I open a bug report?

BR,
Robert Thorpe