diff options
| -rw-r--r-- | src/ChangeLog | 1 | ||||
| -rw-r--r-- | src/xdisp.c | 21 |
2 files changed, 12 insertions, 10 deletions
diff --git a/src/ChangeLog b/src/ChangeLog index 06972a5bcb1..83bcca1db65 100644 --- a/src/ChangeLog +++ b/src/ChangeLog @@ -2,6 +2,7 @@ * xdisp.c (redisplay_window): Don't check buffer's clip_changed flag as a prerequisite for invoking try_scrolling. (Bug#6671) + (try_scrolling): Limit scrolling to 100 screen lines. 2011-03-26 Juanma Barranquero <lekktu@gmail.com> diff --git a/src/xdisp.c b/src/xdisp.c index 6f9f56df979..270d29d0213 100644 --- a/src/xdisp.c +++ b/src/xdisp.c @@ -13016,7 +13016,8 @@ try_scrolling (Lisp_Object window, int just_this_one_p, int dy = 0, amount_to_scroll = 0, scroll_down_p = 0; int extra_scroll_margin_lines = last_line_misfit ? 1 : 0; Lisp_Object aggressive; - int scroll_limit = INT_MAX / FRAME_LINE_HEIGHT (f); + /* We will never try scrolling more than this number of lines. */ + int scroll_limit = 100; #if GLYPH_DEBUG debug_method_add (w, "try_scrolling"); @@ -13032,14 +13033,14 @@ try_scrolling (Lisp_Object window, int just_this_one_p, else this_scroll_margin = 0; - /* Force arg_scroll_conservatively to have a reasonable value, to avoid - overflow while computing how much to scroll. Note that the user - can supply scroll-conservatively equal to `most-positive-fixnum', - which can be larger than INT_MAX. */ + /* Force arg_scroll_conservatively to have a reasonable value, to + avoid scrolling too far away with slow move_it_* functions. Note + that the user can supply scroll-conservatively equal to + `most-positive-fixnum', which can be larger than INT_MAX. */ if (arg_scroll_conservatively > scroll_limit) { - arg_scroll_conservatively = scroll_limit; - scroll_max = INT_MAX; + arg_scroll_conservatively = scroll_limit + 1; + scroll_max = scroll_limit * FRAME_LINE_HEIGHT (f); } else if (scroll_step || arg_scroll_conservatively || temp_scroll_step) /* Compute how much we should try to scroll maximally to bring @@ -13076,7 +13077,7 @@ try_scrolling (Lisp_Object window, int just_this_one_p, /* Compute how many pixels below window bottom to stop searching for PT. This avoids costly search for PT that is far away if the user limited scrolling by a small number of lines, but - always finds PT if arg_scroll_conservatively is set to a large + always finds PT if scroll_conservatively is set to a large number, such as most-positive-fixnum. */ int slack = max (scroll_max, 10 * FRAME_LINE_HEIGHT (f)); int y_to_move = @@ -13128,12 +13129,12 @@ try_scrolling (Lisp_Object window, int just_this_one_p, return SCROLLING_FAILED; start_display (&it, w, startp); - if (scroll_max < INT_MAX) + if (arg_scroll_conservatively <= scroll_limit) move_it_vertically (&it, amount_to_scroll); else { /* Extra precision for users who set scroll-conservatively - to most-positive-fixnum: make sure the amount we scroll + to a large number: make sure the amount we scroll the window start is never less than amount_to_scroll, which was computed as distance from window bottom to point. This matters when lines at window top and lines |