From c5fd6a36777e68013ba6d7839d720bc99db90193 Mon Sep 17 00:00:00 2001
From: Martin Diehl <mail@martin-diehl.net>
Date: Mon, 17 Jan 2022 07:41:17 +0100
Subject: [PATCH] random seed should contain some entropy

setting all elements to the same value does not make sense. Moreover,
negative values are allowed
---
 PRIVATE      |  2 +-
 src/math.f90 | 32 ++++++++++++++------------------
 2 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/PRIVATE b/PRIVATE
index b898a8b55..d570b4a1f 160000
--- a/PRIVATE
+++ b/PRIVATE
@@ -1 +1 @@
-Subproject commit b898a8b5552bd9d1c555edc3d8134564dd32fe53
+Subproject commit d570b4a1fac5b9b99d026d3ff9bf593615e22ce5
diff --git a/src/math.f90 b/src/math.f90
index 3ea4d6a08..db0666ab0 100644
--- a/src/math.f90
+++ b/src/math.f90
@@ -84,38 +84,34 @@ contains
 subroutine math_init
 
   real(pReal), dimension(4) :: randTest
-  integer :: &
-    randSize, &
-    randomSeed                                                                                      !< fixed seeding for pseudo-random number generator, Default 0: use random seed
-  integer, dimension(:), allocatable :: randInit
+  integer :: randSize
+  integer, dimension(:), allocatable :: seed
   class(tNode), pointer :: &
     num_generic
 
+
   print'(/,1x,a)', '<<<+-  math init  -+>>>'; flush(IO_STDOUT)
 
   num_generic => config_numerics%get('generic',defaultVal=emptyDict)
-  randomSeed  = num_generic%get_asInt('random_seed', defaultVal = 0)
 
   call random_seed(size=randSize)
-  allocate(randInit(randSize))
-  if (randomSeed > 0) then
-    randInit = randomSeed
+  allocate(seed(randSize))
+
+  if (num_generic%contains('random_seed')) then
+    seed = num_generic%get_as1dInt('random_seed',requiredSize=randSize)
   else
     call random_seed()
-    call random_seed(get = randInit)
-    randInit(2:randSize) = randInit(1)
-  endif
+    call random_seed(get = seed)
+  end if
 
-  call random_seed(put = randInit)
+  call random_seed(put = seed)
   call random_number(randTest)
 
-  print'(/,a,i2)',                ' size  of random seed:     ', randSize
-  print'(  a,i0)',                ' value of random seed:     ', randInit(1)
-  print'(  a,4(/,26x,f17.14),/)', ' start of random sequence: ', randTest
+  print'(/,a,i2)',              ' size  of random seed:     ', randSize
+  print*,                       'value of random seed:     ', seed
+  print'(  a,4(/,26x,f17.14))', ' start of random sequence: ', randTest
 
-  call random_seed(put = randInit)
-
-  call selfTest
+  call selfTest()
 
 end subroutine math_init