patch 9.0.1015: without /dev/urandom srand() seed is too predictable
Problem: Without /dev/urandom srand() seed is too predictable.
Solution: Use micro seconds and XOR with process ID. (Yasuhiro Matsumoto,
closes #11656)
diff --git a/src/testdir/test_random.vim b/src/testdir/test_random.vim
index afb3044..fdfaea2 100644
--- a/src/testdir/test_random.vim
+++ b/src/testdir/test_random.vim
@@ -1,5 +1,8 @@
" Tests for srand() and rand()
+source check.vim
+source shared.vim
+
func Test_Rand()
let r = srand(123456789)
call assert_equal([1573771921, 319883699, 2742014374, 1324369493], r)
@@ -44,4 +47,20 @@
call rand()
endfunc
+func Test_srand()
+ CheckNotGui
+
+ let cmd = GetVimCommand() .. ' -V -es -c "echo rand()" -c qa!'
+ let bad = 0
+ for _ in range(10)
+ echo cmd
+ let result1 = system(cmd)
+ let result2 = system(cmd)
+ if result1 ==# result2
+ let bad += 1
+ endif
+ endfor
+ call assert_inrange(0, 4, bad)
+endfunc
+
" vim: shiftwidth=2 sts=2 expandtab