make SimulationResultsCmp fail, if a variable has not been found and …

…add a test for it

also add a test for constant singular linear systems which are consistent (or inconsistent) - currently both fail in omc

git-svn-id: https://openmodelica.org/svn/OpenModelica/trunk@20864 f25d12d1-65f4-0310-ae8a-bbce733d8d8e

Compiler/runtime/SimulationResultsCmp.c

@@ -767,7 +767,7 @@ void* SimulationResultsCmp_compareResults(int isResultCmp, int runningTestsuite,
     }
   } else {
     if (success) {
-      *success = 0==vardiffindx;
+      *success = ((ddf.n == 0) && (ngetfailedvars == 0) && (vardiffindx == 0));
     }
   }