slightly improve deepcopy everywhere
bugfix: scrolling up using scroll wheel
The culprit is an ambiguously named helper. put_cursor_on_next_text_line
is not supposed to move to next line if the current line is text.
clarify a misleading test
I'm still using these to periodically reassure myself about the state of
lines2 and its descendants.
delete redundant method description
simpler implementation of bugfix #2
bugfix #3, attempt #2 in search UI
Avoid accidental side-effects.
bugfix #3 in search UI
This is a regression. Scenario: search for a string, then backspace
until it goes empty.