Doing so drops the rectangular selection, and there is no obvious correct behavior for line breaking with a rectangular selection. So, just don't do line breaking in this case.
Fixes #2051.
@elextr please test :) You can view, comment on, or merge this pull request online at:
https://github.com/geany/geany/pull/2135
-- Commit Summary --
* Don't perform line breaking in rectangular selection mode
-- File Changes --
M src/editor.c (2)
-- Patch Links --
https://github.com/geany/geany/pull/2135.patch https://github.com/geany/geany/pull/2135.diff