mirror/emacs
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/emacs.git synced 2025-01-26 19:18:50 +00:00
Code Issues Releases Activity

Fix redisplay with window-start on continuation lines

Browse Source 
* src/xdisp.c (pos_visible_p): Return false if the window starts
after CHARPOS.
(compute_window_start_on_continuation_line): Don't return
window-start position that is after point in the buffer, as the
callers don't expect this to happen, and will generally display an
empty window with the cursor in its middle.  (Bug#23871)
This commit is contained in:
Eli Zaretskii 2016-07-05 19:33:01 +03:00
parent c770dbb098
commit 36e69bd82a
1 changed files with 27 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
src/xdisp.c
View File

@ -1321,6 +1321,11 @@ pos_visible_p (struct window *w, ptrdiff_t charpos, int *x, int *y,
if (CHARPOS (top) > ZV)
SET_TEXT_POS (top, BEGV, BEGV_BYTE);
/* If the top of the window is after CHARPOS, the latter is surely
not visible. */
if (charpos >= 0 && CHARPOS (top) > charpos)
return visible_p;
/* Compute exact mode line heights. */
if (WINDOW_WANTS_MODELINE_P (w))
w->mode_line_height
@ -15512,12 +15517,14 @@ try_scrolling (Lisp_Object window, bool just_this_one_p,
The new window start will be computed, based on W's width, starting
from the start of the continued line. It is the start of the
screen line with the minimum distance from the old start W->start. */
screen line with the minimum distance from the old start W->start,
which is still before point (otherwise point will definitely not
be visible in the window). */
static bool
compute_window_start_on_continuation_line (struct window *w)
{
struct text_pos pos, start_pos;
struct text_pos pos, start_pos, pos_before_pt;
bool window_start_changed_p = false;
SET_TEXT_POS_FROM_MARKER (start_pos, w->start);
@ -15545,10 +15552,14 @@ compute_window_start_on_continuation_line (struct window *w)
reseat_at_previous_visible_line_start (&it);
/* If the line start is "too far" away from the window start,
say it takes too much time to compute a new window start. */
if (CHARPOS (start_pos) - IT_CHARPOS (it)
/* PXW: Do we need upper bounds here? */
< WINDOW_TOTAL_LINES (w) * WINDOW_TOTAL_COLS (w))
say it takes too much time to compute a new window start.
Also, give up if the line start is after point, as in that
case point will not be visible with any window start we
compute. */
if (IT_CHARPOS (it) <= PT
|| (CHARPOS (start_pos) - IT_CHARPOS (it)
/* PXW: Do we need upper bounds here? */
< WINDOW_TOTAL_LINES (w) * WINDOW_TOTAL_COLS (w)))
{
int min_distance, distance;
@ -15558,12 +15569,14 @@ compute_window_start_on_continuation_line (struct window *w)
decreased, the new window start will be < the old start.
So, we're looking for the display line start with the
minimum distance from the old window start. */
pos = it.current.pos;
pos_before_pt = pos = it.current.pos;
min_distance = INFINITY;
while ((distance = eabs (CHARPOS (start_pos) - IT_CHARPOS (it))),
distance < min_distance)
{
min_distance = distance;
if (CHARPOS (pos) <= PT)
pos_before_pt = pos;
pos = it.current.pos;
if (it.line_wrap == WORD_WRAP)
{
@ -15586,6 +15599,13 @@ compute_window_start_on_continuation_line (struct window *w)
move_it_by_lines (&it, 1);
}
/* It makes very little sense to make the new window start
after point, as point won't be visible. If that's what
the loop above finds, fall back on the candidate before
or at point that is closest to the old window start. */
if (CHARPOS (pos) > PT)
pos = pos_before_pt;
/* Set the window start there. */
SET_MARKER_FROM_TEXT_POS (w->start, pos);
window_start_changed_p = true;