Patch 8.1.2343
Problem: Using time() for srand() is not very random.
Solution: use /dev/urandom if available
Files: src/evalfunc.c, src/testdir/test_random.vim
*** ../vim-8.1.2342/src/evalfunc.c 2019-11-25 15:40:28.849612230 +0100
--- src/evalfunc.c 2019-11-26 12:14:53.058068739 +0100
***************
*** 7095,7104 ****
static void
f_srand(typval_T *argvars, typval_T *rettv)
{
if (rettv_list_alloc(rettv) == FAIL)
return;
if (argvars[0].v_type == VAR_UNKNOWN)
! list_append_number(rettv->vval.v_list, (varnumber_T)vim_time());
else
{
int error = FALSE;
--- 7095,7139 ----
static void
f_srand(typval_T *argvars, typval_T *rettv)
{
+ static int dev_urandom_state = -1; // FAIL or OK once tried
+
if (rettv_list_alloc(rettv) == FAIL)
return;
if (argvars[0].v_type == VAR_UNKNOWN)
! {
! if (dev_urandom_state != FAIL)
! {
! int fd = open("/dev/urandom", O_RDONLY);
! struct {
! union {
! UINT32_T number;
! char bytes[sizeof(UINT32_T)];
! } cont;
! } buf;
!
! // Attempt reading /dev/urandom.
! if (fd == -1)
! dev_urandom_state = FAIL;
! else
! {
! buf.cont.number = 0;
! if (read(fd, buf.cont.bytes, sizeof(UINT32_T))
! != sizeof(UINT32_T))
! dev_urandom_state = FAIL;
! else
! {
! dev_urandom_state = OK;
! list_append_number(rettv->vval.v_list,
! (varnumber_T)buf.cont.number);
! }
! close(fd);
! }
!
! }
! if (dev_urandom_state != OK)
! // Reading /dev/urandom doesn't work, fall back to time().
! list_append_number(rettv->vval.v_list, (varnumber_T)vim_time());
! }
else
{
int error = FALSE;
***************
*** 7107,7113 ****
if (error)
return;
! list_append_number(rettv->vval.v_list, x);
}
list_append_number(rettv->vval.v_list, 362436069);
list_append_number(rettv->vval.v_list, 521288629);
--- 7142,7148 ----
if (error)
return;
! list_append_number(rettv->vval.v_list, (varnumber_T)x);
}
list_append_number(rettv->vval.v_list, 362436069);
list_append_number(rettv->vval.v_list, 521288629);
*** ../vim-8.1.2342/src/testdir/test_random.vim 2019-11-25 15:40:28.853612211
+0100
--- src/testdir/test_random.vim 2019-11-26 12:21:15.508414423 +0100
***************
*** 11,19 ****
call test_settime(12341234)
let s = srand()
! call assert_equal(s, srand())
! call test_settime(12341235)
! call assert_notequal(s, srand())
call srand()
let v = rand()
--- 11,25 ----
call test_settime(12341234)
let s = srand()
! if filereadable('/dev/urandom')
! " using /dev/urandom
! call assert_notequal(s, srand())
! else
! " using time()
! call assert_equal(s, srand())
! call test_settime(12341235)
! call assert_notequal(s, srand())
! endif
call srand()
let v = rand()
***************
*** 25,28 ****
--- 31,36 ----
call assert_fails('echo rand([1, [2], 3, 4])', 'E475:')
call assert_fails('echo rand([1, 2, [3], 4])', 'E475:')
call assert_fails('echo rand([1, 2, 3, [4]])', 'E475:')
+
+ call test_settime(0)
endfunc
*** ../vim-8.1.2342/src/version.c 2019-11-25 15:40:28.853612211 +0100
--- src/version.c 2019-11-26 12:22:24.704102512 +0100
***************
*** 739,740 ****
--- 739,742 ----
{ /* Add new patch number below this line */
+ /**/
+ 2343,
/**/
--
hundred-and-one symptoms of being an internet addict:
122. You ask if the Netaholics Anonymous t-shirt you ordered can be
sent to you via e-mail.
/// Bram Moolenaar -- [email protected] -- http://www.Moolenaar.net \\\
/// sponsor Vim, vote for features -- http://www.Vim.org/sponsor/ \\\
\\\ an exciting new programming language -- http://www.Zimbu.org ///
\\\ help me help AIDS victims -- http://ICCF-Holland.org ///
--
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