Do not dereference and write through a null pointer during loop invariant removal.

2019-12-22 19:58:57 -06:00 · 2019-12-22 19:58:57 -06:00 · 2fb075ce58
parent 095060ca70
commit 2fb075ce58
1 changed files with 2 additions and 1 deletions
--- a/DAG.pas
+++ b/DAG.pas
@ -3255,7 +3255,8 @@ var
   new(dp);
   dp^.last := nil;
   dp^.next := dom;
-   dom^.last := dp;
+   if dom <> nil then
+      dom^.last := dp;
   dom := dp;
   dp^.dfn := dfn;
   end; {AddDominator}