* grub-core/gfxmenu/gui_list.c (draw_scrollbar): Avoid

division by-zero and senseless negative divisions.
This commit is contained in:
Vladimir Serbinenko 2013-11-08 15:44:39 +01:00
parent 6af7d49b92
commit d06de6c871
2 changed files with 31 additions and 7 deletions

View file

@ -1,3 +1,8 @@
2013-11-08 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/gfxmenu/gui_list.c (draw_scrollbar): Avoid
division by-zero and senseless negative divisions.
2013-11-08 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/gfxmenu/gui_circular_progress.c (circprog_paint): Avoid

View file

@ -251,18 +251,24 @@ draw_scrollbar (list_impl_t self,
int value, int extent, int min, int max,
int scrollbar_width, int scrollbar_height)
{
unsigned thumby, thumbheight;
grub_gfxmenu_box_t frame = self->scrollbar_frame;
grub_gfxmenu_box_t thumb = self->scrollbar_thumb;
int frame_vertical_pad = (frame->get_top_pad (frame)
+ frame->get_bottom_pad (frame));
int frame_horizontal_pad = (frame->get_left_pad (frame)
+ frame->get_right_pad (frame));
int thumb_vertical_pad = (thumb->get_top_pad (thumb)
+ thumb->get_bottom_pad (thumb));
unsigned thumb_vertical_pad = (thumb->get_top_pad (thumb)
+ thumb->get_bottom_pad (thumb));
int thumb_horizontal_pad = (thumb->get_left_pad (thumb)
+ thumb->get_right_pad (thumb));
int tracktop = frame->get_top_pad (frame);
int tracklen = scrollbar_height - frame_vertical_pad;
unsigned tracklen;
if (scrollbar_height <= frame_vertical_pad)
tracklen = 0;
else
tracklen = scrollbar_height - frame_vertical_pad;
frame->set_content_size (frame,
scrollbar_width - frame_horizontal_pad,
tracklen);
@ -271,15 +277,28 @@ draw_scrollbar (list_impl_t self,
tracklen += thumb_vertical_pad;
tracktop -= thumb->get_top_pad (thumb);
}
int thumby = tracktop + tracklen * (value - min) / (max - min);
int thumbheight = tracklen * extent / (max - min) + 1;
if (value <= min || max <= min)
thumby = 0;
else
thumby = ((unsigned) tracklen * (value - min))
/ ((unsigned) (max - min));
if (max <= min)
thumbheight = 1;
else
thumbheight = ((unsigned) (tracklen * extent)
/ ((unsigned) (max - min))) + 1;
/* Rare occasion: too many entries or too low height. */
if (thumbheight < thumb_vertical_pad)
{
thumbheight = thumb_vertical_pad;
thumby = tracktop + ((tracklen - thumb_vertical_pad) * (value - min)
/ (max - extent));
if (value <= min || max <= extent
|| tracklen <= thumb_vertical_pad)
thumby = 0;
else
thumby = ((unsigned) ((tracklen - thumb_vertical_pad) * (value - min))
/ ((unsigned)(max - extent)));
}
thumby += tracktop;
int thumbx = frame->get_left_pad (frame);
int thumbwidth = scrollbar_width - frame_horizontal_pad;
if (!self->scrollbar_thumb_overlay)