-
- SET_TEXT_POS (pt, PT, PT_BYTE);
- start_display (&it, w, pt);
- move_it_by_lines (&it, XINT (lines), 0);
- SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
+
+ if (noninteractive)
+ {
+ struct position pos;
+ pos = *vmotion (PT, XINT (lines), w);
+ SET_PT_BOTH (pos.bufpos, pos.bytepos);
+ }
+ else
+ {
+ int it_start;
+
+ SET_TEXT_POS (pt, PT, PT_BYTE);
+ start_display (&it, w, pt);
+
+ /* Scan from the start of the line containing PT. If we don't
+ do this, we start moving with IT->current_x == 0, while PT is
+ really at some x > 0. The effect is, in continuation lines, that
+ we end up with the iterator placed at where it thinks X is 0,
+ while the end position is really at some X > 0, the same X that
+ PT had. */
+ it_start = IT_CHARPOS (it);
+ reseat_at_previous_visible_line_start (&it);
+ it.current_x = it.hpos = 0;
+ move_it_to (&it, PT, -1, -1, -1, MOVE_TO_POS);
+
+ /* Move back if we got too far. This may happen if
+ truncate-lines is on and PT is beyond right margin. */
+ if (IT_CHARPOS (it) > it_start && XINT (lines) > 0)
+ move_it_by_lines (&it, -1, 0);
+
+ it.vpos = 0;
+ /* Do this even if LINES is 0, so that we move back
+ to the beginning of the current line as we ought. */
+ move_it_by_lines (&it, XINT (lines), 0);
+
+ SET_PT_BOTH (IT_CHARPOS (it), IT_BYTEPOS (it));
+ }