SCI_LINEDOWN goes down only one display line, hence when line wrapping was enabled and a line wrapped over more than two lines, it was impossible to go to the next actual line when pressing j.
Note that this still doesn't emulate vim behavior correctly where caret-x position is saved for actual lines and not display lines. But this change at least makes j go the next line when wrapping is enabled.
Note that I'm not completely sure whether this change retains all workarounds [mentioned in `cmd_goto_up`](https://github.com/geany/geany-plugins/blob/341cab4e13c122b2b74e6f31a43be9ad...). You can view, comment on, or merge this pull request online at:
https://github.com/geany/geany-plugins/pull/748
-- Commit Summary --
* vimode: Fix goto_down with line wrapping
-- File Changes --
M vimode/src/cmds/motion.c (2)
-- Patch Links --
https://github.com/geany/geany-plugins/pull/748.patch https://github.com/geany/geany-plugins/pull/748.diff