Fix a problem where an operator such as <= on an optional type would sometimes lead to an internal compiler error. Fixes #898.

Author: guidotack

changes.rst

@@ -24,6 +24,8 @@ Bug fixes:
    tuples/records containing var fields (:bugref:`919`).
 -  Fix problem where using an iterator of variable tuple or record types could
    result in a segfault (:bugref:`901`).
+-  Fix a problem where an operator such as ``<=`` on an optional type would
+   sometimes lead to an internal compiler error (:bugref:`898`).
 
 .. _v2.9.2:
 

lib/flatten/flatten_call.cpp

@@ -971,7 +971,8 @@ EE flatten_call(EnvI& env, const Ctx& input_ctx, Expression* e, VarDecl* r, VarD
       if (cid == c->id()) {
         try {
           auto* cr_d = env.model->matchFn(env, cr_c, false);
-          if (cr_d != nullptr) {
+          if (cr_d != nullptr &&
+              !cr_d->ann().contains(env.constants.ann.mzn_internal_representation)) {
             decl = cr_d;
           }
         } catch (TypeError&) { /* NOLINT(bugprone-empty-catch) */

tests/spec/unit/compilation/test_bug_898.mzn

@@ -0,0 +1,9 @@
+/***
+!Test
+solvers: [gecode]
+expected: !Result
+  solution: !Solution
+***/
+array[1..1] of var opt 0..10: y;
+constraint y = [1];
+constraint y[1] <= 4;