[vala/0.40] vala: Handle PointerType and VoidType in Constant.check_const_type()

[Rico Tzschichholz <ricotz src gnome org>]

commit 092a296296a3311698e683237fa922d764f288c7
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Feb 18 17:12:19 2020 +0100

    vala: Handle PointerType and VoidType in Constant.check_const_type()
    
    This caused criticals like:
    
      vala_typesymbol_is_subtype_of: assertion 'self != NULL' failed

 tests/Makefile.am                    | 1 +
 tests/semantic/constant-pointer.test | 6 ++++++
 vala/valaconstant.vala               | 2 ++
 3 files changed, 9 insertions(+)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index f3d97b2d3..711103c40 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -638,6 +638,7 @@ TESTS = \
        semantic/class-too-few-type-arguments.test \
        semantic/class-too-many-type-arguments.test \
        semantic/constant-extern.test \
+       semantic/constant-pointer.test \
        semantic/constant-value.test \
        semantic/constant-value-missing.test \
        semantic/constant-value-type.test \
diff --git a/tests/semantic/constant-pointer.test b/tests/semantic/constant-pointer.test
new file mode 100644
index 000000000..23235c23e
--- /dev/null
+++ b/tests/semantic/constant-pointer.test
@@ -0,0 +1,6 @@
+Invalid Code
+
+const int* FOO = 0;
+
+void main () {
+}
diff --git a/vala/valaconstant.vala b/vala/valaconstant.vala
index 1599b267f..e96b047e0 100644
--- a/vala/valaconstant.vala
+++ b/vala/valaconstant.vala
@@ -195,6 +195,8 @@ public class Vala.Constant : Symbol, Lockable {
        bool check_const_type (DataType type, CodeContext context) {
                if (type is ValueType) {
                        return true;
+               } else if (type is VoidType || type is PointerType) {
+                       return false;
                } else if (type is ArrayType) {
                        var array_type = type as ArrayType;
                        return check_const_type (array_type.element_type, context);