From de92a50b9e157cac071355b9836717e62b9edff1 Mon Sep 17 00:00:00 2001 From: YAMAMOTO Mitsuharu Date: Mon, 9 Jan 2012 17:23:36 +0800 Subject: [PATCH] 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. --- src/ChangeLog | 6 +++++ src/dispnew.c | 74 +++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 72 insertions(+), 8 deletions(-) diff --git a/src/ChangeLog b/src/ChangeLog index 55cc8e8bf27..d0c89f2e44c 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -1,3 +1,9 @@ +2012-01-09 YAMAMOTO Mitsuharu + + * 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 * dispnew.c (scrolling_window): Fix incorrect indices in accessing diff --git a/src/dispnew.c b/src/dispnew.c index c116c3f7c47..45ad9df7da9 100644 --- a/src/dispnew.c +++ b/src/dispnew.c @@ -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; } } -- 2.39.2