Avoid crashes in very large buffers with long lines

* src/xdisp.c (get_large_narrowing_begv, get_large_narrowing_zv)
(get_medium_narrowing_begv, get_medium_narrowing_zv): Use
'ptrdiff_t' instead of 'int', to prevent integer overflow in
large buffers.  (Bug#72497)
This commit is contained in:
Eli Zaretskii 2024-08-06 21:19:49 +03:00
parent 3817355aed
commit f1e37ae423

View file

@ -3621,14 +3621,14 @@ get_narrowed_len (struct window *w)
static ptrdiff_t
get_medium_narrowing_begv (struct window *w, ptrdiff_t pos)
{
int len = get_narrowed_len (w);
ptrdiff_t len = get_narrowed_len (w);
return max ((pos / len - 1) * len, BEGV);
}
static ptrdiff_t
get_medium_narrowing_zv (struct window *w, ptrdiff_t pos)
{
int len = get_narrowed_len (w);
ptrdiff_t len = get_narrowed_len (w);
return min ((pos / len + 1) * len, ZV);
}
@ -3678,9 +3678,9 @@ get_large_narrowing_begv (ptrdiff_t pos)
{
if (long_line_optimizations_region_size <= 0)
return BEGV;
int len = long_line_optimizations_region_size / 2;
int begv = max (pos - len, BEGV);
int limit = long_line_optimizations_bol_search_limit;
ptrdiff_t len = long_line_optimizations_region_size / 2;
ptrdiff_t begv = max (pos - len, BEGV);
ptrdiff_t limit = long_line_optimizations_bol_search_limit;
while (limit > 0)
{
if (begv == BEGV || FETCH_BYTE (CHAR_TO_BYTE (begv) - 1) == '\n')
@ -3696,7 +3696,7 @@ get_large_narrowing_zv (ptrdiff_t pos)
{
if (long_line_optimizations_region_size <= 0)
return ZV;
int len = long_line_optimizations_region_size / 2;
ptrdiff_t len = long_line_optimizations_region_size / 2;
return min (pos + len, ZV);
}