From 6ba4a6e6c67d51b3900b1e05df1ee821107831b5 Mon Sep 17 00:00:00 2001
From: Monty Montgomery <xiphmont@gmail.com>
Date: Sun, 15 May 2022 00:36:17 -0400
Subject: [PATCH] Correct deletion of non-allocated memory in ngarray

A default-constructed (or just empty) ngarray will have 'ownmem' set
despite not having an allocated data array.  Destructor would then
trigger an abort.
---
 libsrc/general/ngarray.hpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libsrc/general/ngarray.hpp b/libsrc/general/ngarray.hpp
index 05639aea..1b16c46b 100644
--- a/libsrc/general/ngarray.hpp
+++ b/libsrc/general/ngarray.hpp
@@ -295,8 +295,9 @@ namespace netgen
     /// if responsible, deletes memory
     ~NgArray()
     {
-      if (ownmem)
-	delete [] data;
+      if (data)
+        if (ownmem)
+          delete [] data;
     }
 
     /// Change logical size. If necessary, do reallocation. Keeps contents.
@@ -374,8 +375,9 @@ namespace netgen
     /// Deallocate memory
     void DeleteAll ()
     {
-      if (ownmem)
-	delete [] data;
+      if (data)
+        if (ownmem)
+          delete [] data;
       data = 0;
       size = allocsize = 0;
     }