From 6ba1f8ee683ba00ba365d48e3ff459f265cf1406 Mon Sep 17 00:00:00 2001
From: kabdelhak <38032125+kabdelhak@users.noreply.github.com>
Date: Wed, 15 May 2024 10:57:11 +0200
Subject: [PATCH] [NB] update event detection (#12427)

- fix detecting pre variables as conditions after swapping execution order of Events and DetectStates modules
---
 OMCompiler/Compiler/NBackEnd/Modules/2_Pre/NBEvents.mo | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/OMCompiler/Compiler/NBackEnd/Modules/2_Pre/NBEvents.mo b/OMCompiler/Compiler/NBackEnd/Modules/2_Pre/NBEvents.mo
index 2ec1d9c586..a99a18b698 100644
--- a/OMCompiler/Compiler/NBackEnd/Modules/2_Pre/NBEvents.mo
+++ b/OMCompiler/Compiler/NBackEnd/Modules/2_Pre/NBEvents.mo
@@ -1029,6 +1029,13 @@ protected
         Pointer.update(bucket_ptr, bucket);
       then exp;
 
+      // replace $PRE variables with auxiliaries
+      // necessary if the $PRE variable is a when condition (cannot check the pre of a pre variable)
+      case Expression.CREF() guard(BVariable.isPrevious(BVariable.getVarPointer(exp.cref))) algorithm
+        (exp, bucket) := CompositeEvent.add(Condition.CONDITION(exp, iter), Pointer.access(bucket_ptr), true);
+        Pointer.update(bucket_ptr, bucket);
+      then exp;
+
       // ToDo: math events (check the call name in a function and merge with sample case?)
 
       else exp;