Fix vertical cursor motion when there's a display string with newline at EOL.
src/xdisp.c (row_for_charpos_p): New function, with code of cursor_row_p, but accepts an additional argument CHARPOS instead of using a hardcoded PT. (cursor_row_p): Call row_for_charpos_p with 2nd argument PT. (row_containing_pos): Call row_for_charpos_p instead of partially doing the same. Fixes cursor positioning under longlines-mode when longlines-show-effect includes more than one newline, when moving the cursor vertically up.
Showing with 33 additions and 13 deletions