Commit de92a50b authored by YAMAMOTO Mitsuharu's avatar YAMAMOTO Mitsuharu Committed by Chong Yidong

Fix glitch in scrolling_window (backport from trunk).

* dispnew.c (scrolling_window): Truncate overlaps in copy
destination of scroll runs so as to avoid assigning disabled bogus
rows and unnecessary graphics copy operations.
parent d58cba75
2012-01-09 YAMAMOTO Mitsuharu <mituharu@math.s.chiba-u.ac.jp>
* dispnew.c (scrolling_window): Truncate overlaps in copy
destination of scroll runs so as to avoid assigning disabled bogus
rows and unnecessary graphics copy operations.
2012-01-09 Eli Zaretskii <eliz@gnu.org>
* dispnew.c (scrolling_window): Fix incorrect indices in accessing
......
......@@ -5208,18 +5208,69 @@ scrolling_window (w, header_line_p)
{
rif->clear_window_mouse_face (w);
rif->scroll_run_hook (w, r);
}
/* Truncate runs that copy to where we copied to, and
invalidate runs that copy from where we copied to. */
for (j = nruns - 1; j > i; --j)
{
struct run *p = runs[j];
int truncated_p = 0;
/* Invalidate runs that copy from where we copied to. */
for (j = i + 1; j < nruns; ++j)
if (p->nrows > 0
&& p->desired_y < r->desired_y + r->height
&& p->desired_y + p->height > r->desired_y)
{
struct run *p = runs[j];
if (p->desired_y < r->desired_y)
{
p->nrows = r->desired_vpos - p->desired_vpos;
p->height = r->desired_y - p->desired_y;
truncated_p = 1;
}
else
{
int nrows_copied = (r->desired_vpos + r->nrows
- p->desired_vpos);
if (p->nrows <= nrows_copied)
p->nrows = 0;
else
{
int height_copied = (r->desired_y + r->height
- p->desired_y);
p->current_vpos += nrows_copied;
p->desired_vpos += nrows_copied;
p->nrows -= nrows_copied;
p->current_y += height_copied;
p->desired_y += height_copied;
p->height -= height_copied;
truncated_p = 1;
}
}
}
if ((p->current_y >= r->desired_y
if (r->current_y != r->desired_y
/* The condition below is equivalent to
((p->current_y >= r->desired_y
&& p->current_y < r->desired_y + r->height)
|| (p->current_y + p->height >= r->desired_y
|| (p->current_y + p->height > r->desired_y
&& (p->current_y + p->height
< r->desired_y + r->height)))
p->nrows = 0;
<= r->desired_y + r->height)))
because we have 0 < p->height <= r->height. */
&& p->current_y < r->desired_y + r->height
&& p->current_y + p->height > r->desired_y)
p->nrows = 0;
/* Reorder runs by copied pixel lines if truncated. */
if (truncated_p && p->nrows > 0)
{
int k = nruns - 1;
while (runs[k]->nrows == 0 || runs[k]->height < p->height)
k--;
memmove (runs + j, runs + j + 1, (k - j) * sizeof (*runs));
runs[k] = p;
}
}
......@@ -5234,7 +5285,14 @@ scrolling_window (w, header_line_p)
to_overlapped_p = to->overlapped_p;
from->redraw_fringe_bitmaps_p = from->fringe_bitmap_periodic_p;
assign_row (to, from);
to->enabled_p = 1, from->enabled_p = 0;
/* The above `assign_row' actually does swap, so if we had
an overlap in the copy destination of two runs, then
the second run would assign a previously disabled bogus
row. But thanks to the truncation code in the
preceding for-loop, we no longer have such an overlap,
and thus the assigned row should always be enabled. */
xassert (to->enabled_p);
from->enabled_p = 0;
to->overlapped_p = to_overlapped_p;
}
}
......
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