Check cv flag of Ids when generating par functions

This prevents identifiers referring to structs with both par and var members from being considered par.

Fixes #919

Author: cyderize

changes.rst

@@ -8,12 +8,20 @@ https://github.com/MiniZinc/libminizinc/issues.
 
 Bug fixes:
 ^^^^^^^^^^
--  Fix the rewriting of the multidimensional search annotations to ensure correct coercion of arguments (:bugref:`897`).
--  Output location of some errors where the problematic expression previously did not have a location (:bugref:`899`).
--  Fix domain computation to avoid variables being moved to the output model when they are constrained (:bugref:`911`).
--  Fix output processing to also respect the ``-o`` flag when flattening already detects unsatisfiability (:bugref:`908`).
--  Report an error when solving a FlatZinc file that does not contain a solve item (:bugref:`907`).
--  Pass command line options to the compiler phases earlier to avoid problems with e.g. the ``--disable-warnings`` flag (:bugref:`893`).
+-  Fix the rewriting of the multidimensional search annotations to ensure
+   correct coercion of arguments (:bugref:`897`).
+-  Output location of some errors where the problematic expression previously
+   did not have a location (:bugref:`899`).
+-  Fix domain computation to avoid variables being moved to the output model
+   when they are constrained (:bugref:`911`).
+-  Fix output processing to also respect the ``-o`` flag when flattening already
+   detects unsatisfiability (:bugref:`908`).
+-  Report an error when solving a FlatZinc file that does not contain a solve
+   item (:bugref:`907`).
+-  Pass command line options to the compiler phases earlier to avoid problems
+   with e.g. the ``--disable-warnings`` flag (:bugref:`893`).
+-  Fix incorrect generation of par versions of functions referencing top-level
+   tuples/records containing var fields (:bugref:`919`).
 
 .. _v2.9.2:
 

lib/typecheck.cpp

@@ -3568,7 +3568,8 @@ void create_par_versions(Env& env, Model* m, BottomUpIterator<Typer<true>>& bott
         return isPar;
       }
       void vId(const Id* ident) {
-        if (ident->decl() != nullptr && ident->type().isvar() && ident->decl()->toplevel()) {
+        if (ident->decl() != nullptr && (ident->type().isvar() || ident->type().cv()) &&
+            ident->decl()->toplevel()) {
           isPar = false;
         }
       }

tests/spec/unit/regression/github_919.mzn

@@ -0,0 +1,21 @@
+/***
+!Test
+solvers: [gecode]
+expected: !Result
+- !Solution
+  x: 1
+***/
+
+% Previously the compiler would generate an invalid par version of foo()
+% because the type of t was seen as par instead of containing var members
+
+var 1..2: v;
+tuple(var int, int): t = (v, 1);
+
+function var int: bar(var int: x) = 1;
+function int: bar(int: x) = 2;
+
+function var int: foo() = bar(t.1);
+var int: x :: output = foo();
+
+solve minimize v;