[vala/staging: 1/2] vala: Admit that structs are emtpy even with a static property

[Rico Tzschichholz <ricotz src gnome org>]

commit f69ce199190b4579351b82ff2de585da8337dc72
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Thu Nov 29 11:09:51 2018 +0100

    vala: Admit that structs are emtpy even with a static property
    
    See https://gitlab.gnome.org/GNOME/vala/issues/446

 tests/Makefile.am                     |  1 +
 tests/objects/property-static.vala    |  2 ++
 tests/structs/struct-empty-still.test |  8 ++++++++
 vala/valastruct.vala                  | 22 ++++++++++++----------
 4 files changed, 23 insertions(+), 10 deletions(-)
---
diff --git a/tests/Makefile.am b/tests/Makefile.am
index 34614c934..6a85be967 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -187,6 +187,7 @@ TESTS = \
        enums/bug763831.vala \
        enums/bug780050.vala \
        structs/struct_only.vala \
+       structs/struct-empty-still.test \
        structs/struct-no-gtype.vala \
        structs/structs.vala \
        structs/gvalue.vala \
diff --git a/tests/objects/property-static.vala b/tests/objects/property-static.vala
index b5596bd6b..e22448108 100644
--- a/tests/objects/property-static.vala
+++ b/tests/objects/property-static.vala
@@ -15,6 +15,8 @@ class Foo {
 }
 
 struct Bar {
+       public int foo;
+
        static int _bar;
        static int _baz;
 
diff --git a/tests/structs/struct-empty-still.test b/tests/structs/struct-empty-still.test
new file mode 100644
index 000000000..3a1270748
--- /dev/null
+++ b/tests/structs/struct-empty-still.test
@@ -0,0 +1,8 @@
+Invalid Code
+
+struct Foo {
+       public static int bar { get; set; }
+}
+
+void main () {
+}
diff --git a/vala/valastruct.vala b/vala/valastruct.vala
index 4c6f59bcc..ca187b56c 100644
--- a/vala/valastruct.vala
+++ b/vala/valastruct.vala
@@ -530,18 +530,20 @@ public class Vala.Struct : TypeSymbol {
                }
 
                if (!external && !external_package) {
-                       if (base_type == null && get_fields ().size == 0 && !is_boolean_type () && 
!is_integer_type () && !is_floating_type ()) {
-                               error = true;
-                               Report.error (source_reference, "structs cannot be empty: %s".printf(name));
-                       } else if (base_type != null) {
-                               foreach (Field f in fields) {
-                                       if (f.binding == MemberBinding.INSTANCE) {
-                                               error = true;
-                                               Report.error (source_reference, "derived structs may not have 
instance fields");
-                                               break;
-                                       }
+                       bool has_instance_field = false;
+                       foreach (Field f in fields) {
+                               if (f.binding == MemberBinding.INSTANCE) {
+                                       has_instance_field = true;
+                                       break;
                                }
                        }
+                       if (base_type == null && !has_instance_field && !is_boolean_type () && 
!is_integer_type () && !is_floating_type ()) {
+                               error = true;
+                               Report.error (source_reference, "struct `%s' cannot be empty".printf 
(get_full_name ()));
+                       } else if (base_type != null && has_instance_field) {
+                               error = true;
+                               Report.error (source_reference, "derived struct `%s' may not have instance 
fields".printf (get_full_name ()));
+                       }
                }
 
                context.analyzer.current_source_file = old_source_file;