From e6b176d44c0c4868479f648204bb498411e99b05 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Mon, 25 Oct 2021 13:18:41 -0400
Subject: [PATCH] Fixed quicksort algorithms to properly use pre-sorted index
 arrays

---
 src/util/util_sort.f90 | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/src/util/util_sort.f90 b/src/util/util_sort.f90
index a3ad9a15c..84371b773 100644
--- a/src/util/util_sort.f90
+++ b/src/util/util_sort.f90
@@ -93,7 +93,8 @@ module pure subroutine util_sort_index_dp(arr, ind)
          allocate(ind(n))
          ind = [(i, i=1, n)]
       end if
-      allocate(tmparr, source=arr)
+      allocate(tmparr, mold=arr)
+      tmparr(:) = arr(ind(:))
       call qsort_DP(tmparr, ind)
    
       return
@@ -221,7 +222,8 @@ module pure subroutine util_sort_index_i4b(arr, ind)
          allocate(ind(n))
          ind = [(i, i=1, n)]
       end if
-      allocate(tmparr, source=arr)
+      allocate(tmparr, mold=arr)
+      tmparr(:) = arr(ind(:))
       call qsort_I4B(tmparr, ind)
 
       return
@@ -348,7 +350,8 @@ module pure subroutine util_sort_index_sp(arr, ind)
          allocate(ind(n))
          ind = [(i, i=1, n)]
       end if
-      allocate(tmparr, source=arr)
+      allocate(tmparr, mold=arr)
+      tmparr(:) = arr(ind(:))
       call qsort_SP(tmparr, ind)
    
       return