vala: Improve compatibility type checks of array elements in assignments

9 files changed, 1016 insertions, 0 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 8bdfc3a77..844f4c2a7 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -130,6 +130,8 @@ TESTS = \
 	arrays/class-field-initializer.vala \
 	arrays/class-field-length-cname.vala \
 	arrays/constant-element-access.vala \
+	arrays/element-class-assignment.vala \
+	arrays/element-class-assignment-invalid.test \
 	arrays/element-nullable-assignment.vala \
 	arrays/empty-length-0.vala \
 	arrays/expression-bracket.test \
@@ -1330,6 +1332,8 @@ TESTS = \
 	semantic/yield-creation-requires-async-context.test \
 	semantic/yield-creation-requires-async-method.test \
 	semantic/yield-statement-requires-async-context.test \
+	nullability/array-element-class.vala \
+	nullability/array-element-string.vala \
 	nullability/bug611223.vala \
 	nullability/local-variable-invalid-convert.test \
 	nullability/member-access-narrowed-instance.vala \
diff --git a/tests/arrays/element-class-assignment-invalid.test b/tests/arrays/element-class-assignment-invalid.test
new file mode 100644
index 000000000..366bda6ae
--- /dev/null
+++ b/tests/arrays/element-class-assignment-invalid.test
@@ -0,0 +1,12 @@
+Invalid Code
+
+class Foo {
+}
+
+class Bar : Foo {
+}
+
+void main () {
+	Foo[] foos = { new Foo () };
+	unowned Bar[] bars = foos;
+}
diff --git a/tests/arrays/element-class-assignment.c-expected b/tests/arrays/element-class-assignment.c-expected
new file mode 100644
index 000000000..d4f394a89
--- /dev/null
+++ b/tests/arrays/element-class-assignment.c-expected
@@ -0,0 +1,433 @@
+/* arrays_element_class_assignment.c generated by valac, the Vala compiler
+ * generated from arrays_element_class_assignment.vala, do not modify */
+
+#include <glib-object.h>
+#include <gobject/gvaluecollector.h>
+#include <glib.h>
+
+#if !defined(VALA_EXTERN)
+#if defined(_WIN32) || defined(__CYGWIN__)
+#define VALA_EXTERN __declspec(dllexport) extern
+#elif __GNUC__ >= 4
+#define VALA_EXTERN __attribute__((visibility("default"))) extern
+#else
+#define VALA_EXTERN extern
+#endif
+#endif
+
+#define TYPE_FOO (foo_get_type ())
+#define FOO(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), TYPE_FOO, Foo))
+#define FOO_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), TYPE_FOO, FooClass))
+#define IS_FOO(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), TYPE_FOO))
+#define IS_FOO_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), TYPE_FOO))
+#define FOO_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), TYPE_FOO, FooClass))
+
+typedef struct _Foo Foo;
+typedef struct _FooClass FooClass;
+typedef struct _FooPrivate FooPrivate;
+typedef struct _ParamSpecFoo ParamSpecFoo;
+
+#define TYPE_BAR (bar_get_type ())
+#define BAR(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), TYPE_BAR, Bar))
+#define BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), TYPE_BAR, BarClass))
+#define IS_BAR(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), TYPE_BAR))
+#define IS_BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), TYPE_BAR))
+#define BAR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), TYPE_BAR, BarClass))
+
+typedef struct _Bar Bar;
+typedef struct _BarClass BarClass;
+typedef struct _BarPrivate BarPrivate;
+#define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
+#define _vala_return_if_fail(expr, msg) if G_LIKELY (expr) ; else { g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, msg); return; }
+#define _vala_return_val_if_fail(expr, msg, val) if G_LIKELY (expr) ; else { g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, msg); return val; }
+#define _vala_warn_if_fail(expr, msg) if G_LIKELY (expr) ; else g_warn_message (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
+
+struct _Foo {
+	GTypeInstance parent_instance;
+	volatile int ref_count;
+	FooPrivate * priv;
+};
+
+struct _FooClass {
+	GTypeClass parent_class;
+	void (*finalize) (Foo *self);
+};
+
+struct _ParamSpecFoo {
+	GParamSpec parent_instance;
+};
+
+struct _Bar {
+	Foo parent_instance;
+	BarPrivate * priv;
+};
+
+struct _BarClass {
+	FooClass parent_class;
+};
+
+static gpointer foo_parent_class = NULL;
+static gpointer bar_parent_class = NULL;
+
+VALA_EXTERN gpointer foo_ref (gpointer instance);
+VALA_EXTERN void foo_unref (gpointer instance);
+VALA_EXTERN GParamSpec* param_spec_foo (const gchar* name,
+                            const gchar* nick,
+                            const gchar* blurb,
+                            GType object_type,
+                            GParamFlags flags);
+VALA_EXTERN void value_set_foo (GValue* value,
+                    gpointer v_object);
+VALA_EXTERN void value_take_foo (GValue* value,
+                     gpointer v_object);
+VALA_EXTERN gpointer value_get_foo (const GValue* value);
+VALA_EXTERN GType foo_get_type (void) G_GNUC_CONST ;
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (Foo, foo_unref)
+VALA_EXTERN Foo* foo_new (void);
+VALA_EXTERN Foo* foo_construct (GType object_type);
+static void foo_finalize (Foo * obj);
+static GType foo_get_type_once (void);
+VALA_EXTERN GType bar_get_type (void) G_GNUC_CONST ;
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (Bar, foo_unref)
+VALA_EXTERN Bar* bar_new (void);
+VALA_EXTERN Bar* bar_construct (GType object_type);
+static GType bar_get_type_once (void);
+VALA_EXTERN void manam (Foo** foos,
+            gint foos_length1);
+static void _vala_main (void);
+static void _vala_array_destroy (gpointer array,
+                          gssize array_length,
+                          GDestroyNotify destroy_func);
+static void _vala_array_free (gpointer array,
+                       gssize array_length,
+                       GDestroyNotify destroy_func);
+
+Foo*
+foo_construct (GType object_type)
+{
+	Foo* self = NULL;
+	self = (Foo*) g_type_create_instance (object_type);
+	return self;
+}
+
+Foo*
+foo_new (void)
+{
+	return foo_construct (TYPE_FOO);
+}
+
+static void
+value_foo_init (GValue* value)
+{
+	value->data[0].v_pointer = NULL;
+}
+
+static void
+value_foo_free_value (GValue* value)
+{
+	if (value->data[0].v_pointer) {
+		foo_unref (value->data[0].v_pointer);
+	}
+}
+
+static void
+value_foo_copy_value (const GValue* src_value,
+                      GValue* dest_value)
+{
+	if (src_value->data[0].v_pointer) {
+		dest_value->data[0].v_pointer = foo_ref (src_value->data[0].v_pointer);
+	} else {
+		dest_value->data[0].v_pointer = NULL;
+	}
+}
+
+static gpointer
+value_foo_peek_pointer (const GValue* value)
+{
+	return value->data[0].v_pointer;
+}
+
+static gchar*
+value_foo_collect_value (GValue* value,
+                         guint n_collect_values,
+                         GTypeCValue* collect_values,
+                         guint collect_flags)
+{
+	if (collect_values[0].v_pointer) {
+		Foo * object;
+		object = collect_values[0].v_pointer;
+		if (object->parent_instance.g_class == NULL) {
+			return g_strconcat ("invalid unclassed object pointer for value type `", G_VALUE_TYPE_NAME (value), "'", NULL);
+		} else if (!g_value_type_compatible (G_TYPE_FROM_INSTANCE (object), G_VALUE_TYPE (value))) {
+			return g_strconcat ("invalid object type `", g_type_name (G_TYPE_FROM_INSTANCE (object)), "' for value type `", G_VALUE_TYPE_NAME (value), "'", NULL);
+		}
+		value->data[0].v_pointer = foo_ref (object);
+	} else {
+		value->data[0].v_pointer = NULL;
+	}
+	return NULL;
+}
+
+static gchar*
+value_foo_lcopy_value (const GValue* value,
+                       guint n_collect_values,
+                       GTypeCValue* collect_values,
+                       guint collect_flags)
+{
+	Foo ** object_p;
+	object_p = collect_values[0].v_pointer;
+	if (!object_p) {
+		return g_strdup_printf ("value location for `%s' passed as NULL", G_VALUE_TYPE_NAME (value));
+	}
+	if (!value->data[0].v_pointer) {
+		*object_p = NULL;
+	} else if (collect_flags & G_VALUE_NOCOPY_CONTENTS) {
+		*object_p = value->data[0].v_pointer;
+	} else {
+		*object_p = foo_ref (value->data[0].v_pointer);
+	}
+	return NULL;
+}
+
+GParamSpec*
+param_spec_foo (const gchar* name,
+                const gchar* nick,
+                const gchar* blurb,
+                GType object_type,
+                GParamFlags flags)
+{
+	ParamSpecFoo* spec;
+	g_return_val_if_fail (g_type_is_a (object_type, TYPE_FOO), NULL);
+	spec = g_param_spec_internal (G_TYPE_PARAM_OBJECT, name, nick, blurb, flags);
+	G_PARAM_SPEC (spec)->value_type = object_type;
+	return G_PARAM_SPEC (spec);
+}
+
+gpointer
+value_get_foo (const GValue* value)
+{
+	g_return_val_if_fail (G_TYPE_CHECK_VALUE_TYPE (value, TYPE_FOO), NULL);
+	return value->data[0].v_pointer;
+}
+
+void
+value_set_foo (GValue* value,
+               gpointer v_object)
+{
+	Foo * old;
+	g_return_if_fail (G_TYPE_CHECK_VALUE_TYPE (value, TYPE_FOO));
+	old = value->data[0].v_pointer;
+	if (v_object) {
+		g_return_if_fail (G_TYPE_CHECK_INSTANCE_TYPE (v_object, TYPE_FOO));
+		g_return_if_fail (g_value_type_compatible (G_TYPE_FROM_INSTANCE (v_object), G_VALUE_TYPE (value)));
+		value->data[0].v_pointer = v_object;
+		foo_ref (value->data[0].v_pointer);
+	} else {
+		value->data[0].v_pointer = NULL;
+	}
+	if (old) {
+		foo_unref (old);
+	}
+}
+
+void
+value_take_foo (GValue* value,
+                gpointer v_object)
+{
+	Foo * old;
+	g_return_if_fail (G_TYPE_CHECK_VALUE_TYPE (value, TYPE_FOO));
+	old = value->data[0].v_pointer;
+	if (v_object) {
+		g_return_if_fail (G_TYPE_CHECK_INSTANCE_TYPE (v_object, TYPE_FOO));
+		g_return_if_fail (g_value_type_compatible (G_TYPE_FROM_INSTANCE (v_object), G_VALUE_TYPE (value)));
+		value->data[0].v_pointer = v_object;
+	} else {
+		value->data[0].v_pointer = NULL;
+	}
+	if (old) {
+		foo_unref (old);
+	}
+}
+
+static void
+foo_class_init (FooClass * klass,
+                gpointer klass_data)
+{
+	foo_parent_class = g_type_class_peek_parent (klass);
+	((FooClass *) klass)->finalize = foo_finalize;
+}
+
+static void
+foo_instance_init (Foo * self,
+                   gpointer klass)
+{
+	self->ref_count = 1;
+}
+
+static void
+foo_finalize (Foo * obj)
+{
+	Foo * self;
+	self = G_TYPE_CHECK_INSTANCE_CAST (obj, TYPE_FOO, Foo);
+	g_signal_handlers_destroy (self);
+}
+
+static GType
+foo_get_type_once (void)
+{
+	static const GTypeValueTable g_define_type_value_table = { value_foo_init, value_foo_free_value, value_foo_copy_value, value_foo_peek_pointer, "p", value_foo_collect_value, "p", value_foo_lcopy_value };
+	static const GTypeInfo g_define_type_info = { sizeof (FooClass), (GBaseInitFunc) NULL, (GBaseFinalizeFunc) NULL, (GClassInitFunc) foo_class_init, (GClassFinalizeFunc) NULL, NULL, sizeof (Foo), 0, (GInstanceInitFunc) foo_instance_init, &g_define_type_value_table };
+	static const GTypeFundamentalInfo g_define_type_fundamental_info = { (G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE | G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE) };
+	GType foo_type_id;
+	foo_type_id = g_type_register_fundamental (g_type_fundamental_next (), "Foo", &g_define_type_info, &g_define_type_fundamental_info, 0);
+	return foo_type_id;
+}
+
+GType
+foo_get_type (void)
+{
+	static volatile gsize foo_type_id__once = 0;
+	if (g_once_init_enter (&foo_type_id__once)) {
+		GType foo_type_id;
+		foo_type_id = foo_get_type_once ();
+		g_once_init_leave (&foo_type_id__once, foo_type_id);
+	}
+	return foo_type_id__once;
+}
+
+gpointer
+foo_ref (gpointer instance)
+{
+	Foo * self;
+	self = instance;
+	g_atomic_int_inc (&self->ref_count);
+	return instance;
+}
+
+void
+foo_unref (gpointer instance)
+{
+	Foo * self;
+	self = instance;
+	if (g_atomic_int_dec_and_test (&self->ref_count)) {
+		FOO_GET_CLASS (self)->finalize (self);
+		g_type_free_instance ((GTypeInstance *) self);
+	}
+}
+
+Bar*
+bar_construct (GType object_type)
+{
+	Bar* self = NULL;
+	self = (Bar*) foo_construct (object_type);
+	return self;
+}
+
+Bar*
+bar_new (void)
+{
+	return bar_construct (TYPE_BAR);
+}
+
+static void
+bar_class_init (BarClass * klass,
+                gpointer klass_data)
+{
+	bar_parent_class = g_type_class_peek_parent (klass);
+}
+
+static void
+bar_instance_init (Bar * self,
+                   gpointer klass)
+{
+}
+
+static GType
+bar_get_type_once (void)
+{
+	static const GTypeInfo g_define_type_info = { sizeof (BarClass), (GBaseInitFunc) NULL, (GBaseFinalizeFunc) NULL, (GClassInitFunc) bar_class_init, (GClassFinalizeFunc) NULL, NULL, sizeof (Bar), 0, (GInstanceInitFunc) bar_instance_init, NULL };
+	GType bar_type_id;
+	bar_type_id = g_type_register_static (TYPE_FOO, "Bar", &g_define_type_info, 0);
+	return bar_type_id;
+}
+
+GType
+bar_get_type (void)
+{
+	static volatile gsize bar_type_id__once = 0;
+	if (g_once_init_enter (&bar_type_id__once)) {
+		GType bar_type_id;
+		bar_type_id = bar_get_type_once ();
+		g_once_init_leave (&bar_type_id__once, bar_type_id);
+	}
+	return bar_type_id__once;
+}
+
+void
+manam (Foo** foos,
+       gint foos_length1)
+{
+	Foo* _tmp0_;
+	_tmp0_ = foos[0];
+	_vala_assert (IS_BAR (_tmp0_), "foos[0] is Bar");
+}
+
+static void
+_vala_main (void)
+{
+	Bar** bars = NULL;
+	Bar* _tmp0_;
+	Bar** _tmp1_;
+	gint bars_length1;
+	gint _bars_size_;
+	Foo** foos = NULL;
+	gint foos_length1;
+	gint _foos_size_;
+	Foo* _tmp2_;
+	_tmp0_ = bar_new ();
+	_tmp1_ = g_new0 (Bar*, 1 + 1);
+	_tmp1_[0] = _tmp0_;
+	bars = _tmp1_;
+	bars_length1 = 1;
+	_bars_size_ = bars_length1;
+	manam (bars, (gint) bars_length1);
+	foos = bars;
+	foos_length1 = bars_length1;
+	_foos_size_ = foos_length1;
+	_tmp2_ = foos[0];
+	_vala_assert (IS_BAR (_tmp2_), "foos[0] is Bar");
+	bars = (_vala_array_free (bars, bars_length1, (GDestroyNotify) foo_unref), NULL);
+}
+
+int
+main (int argc,
+      char ** argv)
+{
+	_vala_main ();
+	return 0;
+}
+
+static void
+_vala_array_destroy (gpointer array,
+                     gssize array_length,
+                     GDestroyNotify destroy_func)
+{
+	if ((array != NULL) && (destroy_func != NULL)) {
+		gssize i;
+		for (i = 0; i < array_length; i = i + 1) {
+			if (((gpointer*) array)[i] != NULL) {
+				destroy_func (((gpointer*) array)[i]);
+			}
+		}
+	}
+}
+
+static void
+_vala_array_free (gpointer array,
+                  gssize array_length,
+                  GDestroyNotify destroy_func)
+{
+	_vala_array_destroy (array, array_length, destroy_func);
+	g_free (array);
+}
+
diff --git a/tests/arrays/element-class-assignment.vala b/tests/arrays/element-class-assignment.vala
new file mode 100644
index 000000000..e9a602b0b
--- /dev/null
+++ b/tests/arrays/element-class-assignment.vala
@@ -0,0 +1,18 @@
+class Foo {
+}
+
+class Bar : Foo {
+}
+
+void manam (Foo[] foos) {
+	assert (foos[0] is Bar);
+}
+
+void main () {
+	Bar[] bars = { new Bar () };
+
+	manam (bars);
+
+	unowned Foo[] foos = bars;
+	assert (foos[0] is Bar);
+}
diff --git a/tests/nullability/array-element-class.c-expected b/tests/nullability/array-element-class.c-expected
new file mode 100644
index 000000000..e95a59242
--- /dev/null
+++ b/tests/nullability/array-element-class.c-expected
@@ -0,0 +1,433 @@
+/* nullability_array_element_class.c generated by valac, the Vala compiler
+ * generated from nullability_array_element_class.vala, do not modify */
+
+#include <glib-object.h>
+#include <gobject/gvaluecollector.h>
+#include <glib.h>
+
+#if !defined(VALA_EXTERN)
+#if defined(_WIN32) || defined(__CYGWIN__)
+#define VALA_EXTERN __declspec(dllexport) extern
+#elif __GNUC__ >= 4
+#define VALA_EXTERN __attribute__((visibility("default"))) extern
+#else
+#define VALA_EXTERN extern
+#endif
+#endif
+
+#define TYPE_FOO (foo_get_type ())
+#define FOO(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), TYPE_FOO, Foo))
+#define FOO_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), TYPE_FOO, FooClass))
+#define IS_FOO(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), TYPE_FOO))
+#define IS_FOO_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), TYPE_FOO))
+#define FOO_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), TYPE_FOO, FooClass))
+
+typedef struct _Foo Foo;
+typedef struct _FooClass FooClass;
+typedef struct _FooPrivate FooPrivate;
+typedef struct _ParamSpecFoo ParamSpecFoo;
+
+#define TYPE_BAR (bar_get_type ())
+#define BAR(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), TYPE_BAR, Bar))
+#define BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), TYPE_BAR, BarClass))
+#define IS_BAR(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), TYPE_BAR))
+#define IS_BAR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), TYPE_BAR))
+#define BAR_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), TYPE_BAR, BarClass))
+
+typedef struct _Bar Bar;
+typedef struct _BarClass BarClass;
+typedef struct _BarPrivate BarPrivate;
+#define _vala_assert(expr, msg) if G_LIKELY (expr) ; else g_assertion_message_expr (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
+#define _vala_return_if_fail(expr, msg) if G_LIKELY (expr) ; else { g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, msg); return; }
+#define _vala_return_val_if_fail(expr, msg, val) if G_LIKELY (expr) ; else { g_return_if_fail_warning (G_LOG_DOMAIN, G_STRFUNC, msg); return val; }
+#define _vala_warn_if_fail(expr, msg) if G_LIKELY (expr) ; else g_warn_message (G_LOG_DOMAIN, __FILE__, __LINE__, G_STRFUNC, msg);
+
+struct _Foo {
+	GTypeInstance parent_instance;
+	volatile int ref_count;
+	FooPrivate * priv;
+};
+
+struct _FooClass {
+	GTypeClass parent_class;
+	void (*finalize) (Foo *self);
+};
+
+struct _ParamSpecFoo {
+	GParamSpec parent_instance;
+};
+
+struct _Bar {
+	Foo parent_instance;
+	BarPrivate * priv;
+};
+
+struct _BarClass {
+	FooClass parent_class;
+};
+
+static gpointer foo_parent_class = NULL;
+static gpointer bar_parent_class = NULL;
+
+VALA_EXTERN gpointer foo_ref (gpointer instance);
+VALA_EXTERN void foo_unref (gpointer instance);
+VALA_EXTERN GParamSpec* param_spec_foo (const gchar* name,
+                            const gchar* nick,
+                            const gchar* blurb,
+                            GType object_type,
+                            GParamFlags flags);
+VALA_EXTERN void value_set_foo (GValue* value,
+                    gpointer v_object);
+VALA_EXTERN void value_take_foo (GValue* value,
+                     gpointer v_object);
+VALA_EXTERN gpointer value_get_foo (const GValue* value);
+VALA_EXTERN GType foo_get_type (void) G_GNUC_CONST ;
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (Foo, foo_unref)
+VALA_EXTERN Foo* foo_new (void);
+VALA_EXTERN Foo* foo_construct (GType object_type);
+static void foo_finalize (Foo * obj);
+static GType foo_get_type_once (void);
+VALA_EXTERN GType bar_get_type (void) G_GNUC_CONST ;
+G_DEFINE_AUTOPTR_CLEANUP_FUNC (Bar, foo_unref)
+VALA_EXTERN Bar* bar_new (void);
+VALA_EXTERN Bar* bar_construct (GType object_type);
+static GType bar_get_type_once (void);
+VALA_EXTERN void manam (Foo** foos,
+            gint foos_length1);
+static void _vala_main (void);
+static void _vala_array_destroy (gpointer array,
+                          gssize array_length,
+                          GDestroyNotify destroy_func);
+static void _vala_array_free (gpointer array,
+                       gssize array_length,
+                       GDestroyNotify destroy_func);
+
+Foo*
+foo_construct (GType object_type)
+{
+	Foo* self = NULL;
+	self = (Foo*) g_type_create_instance (object_type);
+	return self;
+}
+
+Foo*
+foo_new (void)
+{
+	return foo_construct (TYPE_FOO);
+}
+
+static void
+value_foo_init (GValue* value)
+{
+	value->data[0].v_pointer = NULL;
+}
+
+static void
+value_foo_free_value (GValue* value)
+{
+	if (value->data[0].v_pointer) {
+		foo_unref (value->data[0].v_pointer);
+	}
+}
+
+static void
+value_foo_copy_value (const GValue* src_value,
+                      GValue* dest_value)
+{
+	if (src_value->data[0].v_pointer) {
+		dest_value->data[0].v_pointer = foo_ref (src_value->data[0].v_pointer);
+	} else {
+		dest_value->data[0].v_pointer = NULL;
+	}
+}
+
+static gpointer
+value_foo_peek_pointer (const GValue* value)
+{
+	return value->data[0].v_pointer;
+}
+
+static gchar*
+value_foo_collect_value (GValue* value,
+                         guint n_collect_values,
+                         GTypeCValue* collect_values,
+                         guint collect_flags)
+{
+	if (collect_values[0].v_pointer) {
+		Foo * object;
+		object = collect_values[0].v_pointer;
+		if (object->parent_instance.g_class == NULL) {
+			return g_strconcat ("invalid unclassed object pointer for value type `", G_VALUE_TYPE_NAME (value), "'", NULL);
+		} else if (!g_value_type_compatible (G_TYPE_FROM_INSTANCE (object), G_VALUE_TYPE (value))) {
+			return g_strconcat ("invalid object type `", g_type_name (G_TYPE_FROM_INSTANCE (object)), "' for value type `", G_VALUE_TYPE_NAME (value), "'", NULL);
+		}
+		value->data[0].v_pointer = foo_ref (object);
+	} else {
+		value->data[0].v_pointer = NULL;
+	}
+	return NULL;
+}
+
+static gchar*
+value_foo_lcopy_value (const GValue* value,
+                       guint n_collect_values,
+                       GTypeCValue* collect_values,
+                       guint collect_flags)
+{
+	Foo ** object_p;
+	object_p = collect_values[0].v_pointer;
+	if (!object_p) {
+		return g_strdup_printf ("value location for `%s' passed as NULL", G_VALUE_TYPE_NAME (value));
+	}
+	if (!value->data[0].v_pointer) {
+		*object_p = NULL;
+	} else if (collect_flags & G_VALUE_NOCOPY_CONTENTS) {
+		*object_p = value->data[0].v_pointer;
+	} else {
+		*object_p = foo_ref (value->data[0].v_pointer);
+	}
+	return NULL;
+}
+
+GParamSpec*
+param_spec_foo (const gchar* name,
+                const gchar* nick,
+                const gchar* blurb,
+                GType object_type,
+                GParamFlags flags)
+{
+	ParamSpecFoo* spec;
+	g_return_val_if_fail (g_type_is_a (object_type, TYPE_FOO), NULL);
+	spec = g_param_spec_internal (G_TYPE_PARAM_OBJECT, name, nick, blurb, flags);
+	G_PARAM_SPEC (spec)->value_type = object_type;
+	return G_PARAM_SPEC (spec);
+}
+
+gpointer
+value_get_foo (const GValue* value)
+{
+	g_return_val_if_fail (G_TYPE_CHECK_VALUE_TYPE (value, TYPE_FOO), NULL);
+	return value->data[0].v_pointer;
+}
+
+void
+value_set_foo (GValue* value,
+               gpointer v_object)
+{
+	Foo * old;
+	g_return_if_fail (G_TYPE_CHECK_VALUE_TYPE (value, TYPE_FOO));
+	old = value->data[0].v_pointer;
+	if (v_object) {
+		g_return_if_fail (G_TYPE_CHECK_INSTANCE_TYPE (v_object, TYPE_FOO));
+		g_return_if_fail (g_value_type_compatible (G_TYPE_FROM_INSTANCE (v_object), G_VALUE_TYPE (value)));
+		value->data[0].v_pointer = v_object;
+		foo_ref (value->data[0].v_pointer);
+	} else {
+		value->data[0].v_pointer = NULL;
+	}
+	if (old) {
+		foo_unref (old);
+	}
+}
+
+void
+value_take_foo (GValue* value,
+                gpointer v_object)
+{
+	Foo * old;
+	g_return_if_fail (G_TYPE_CHECK_VALUE_TYPE (value, TYPE_FOO));
+	old = value->data[0].v_pointer;
+	if (v_object) {
+		g_return_if_fail (G_TYPE_CHECK_INSTANCE_TYPE (v_object, TYPE_FOO));
+		g_return_if_fail (g_value_type_compatible (G_TYPE_FROM_INSTANCE (v_object), G_VALUE_TYPE (value)));
+		value->data[0].v_pointer = v_object;
+	} else {
+		value->data[0].v_pointer = NULL;
+	}
+	if (old) {
+		foo_unref (old);
+	}
+}
+
+static void
+foo_class_init (FooClass * klass,
+                gpointer klass_data)
+{
+	foo_parent_class = g_type_class_peek_parent (klass);
+	((FooClass *) klass)->finalize = foo_finalize;
+}
+
+static void
+foo_instance_init (Foo * self,
+                   gpointer klass)
+{
+	self->ref_count = 1;
+}
+
+static void
+foo_finalize (Foo * obj)
+{
+	Foo * self;
+	self = G_TYPE_CHECK_INSTANCE_CAST (obj, TYPE_FOO, Foo);
+	g_signal_handlers_destroy (self);
+}
+
+static GType
+foo_get_type_once (void)
+{
+	static const GTypeValueTable g_define_type_value_table = { value_foo_init, value_foo_free_value, value_foo_copy_value, value_foo_peek_pointer, "p", value_foo_collect_value, "p", value_foo_lcopy_value };
+	static const GTypeInfo g_define_type_info = { sizeof (FooClass), (GBaseInitFunc) NULL, (GBaseFinalizeFunc) NULL, (GClassInitFunc) foo_class_init, (GClassFinalizeFunc) NULL, NULL, sizeof (Foo), 0, (GInstanceInitFunc) foo_instance_init, &g_define_type_value_table };
+	static const GTypeFundamentalInfo g_define_type_fundamental_info = { (G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE | G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE) };
+	GType foo_type_id;
+	foo_type_id = g_type_register_fundamental (g_type_fundamental_next (), "Foo", &g_define_type_info, &g_define_type_fundamental_info, 0);
+	return foo_type_id;
+}
+
+GType
+foo_get_type (void)
+{
+	static volatile gsize foo_type_id__once = 0;
+	if (g_once_init_enter (&foo_type_id__once)) {
+		GType foo_type_id;
+		foo_type_id = foo_get_type_once ();
+		g_once_init_leave (&foo_type_id__once, foo_type_id);
+	}
+	return foo_type_id__once;
+}
+
+gpointer
+foo_ref (gpointer instance)
+{
+	Foo * self;
+	self = instance;
+	g_atomic_int_inc (&self->ref_count);
+	return instance;
+}
+
+void
+foo_unref (gpointer instance)
+{
+	Foo * self;
+	self = instance;
+	if (g_atomic_int_dec_and_test (&self->ref_count)) {
+		FOO_GET_CLASS (self)->finalize (self);
+		g_type_free_instance ((GTypeInstance *) self);
+	}
+}
+
+Bar*
+bar_construct (GType object_type)
+{
+	Bar* self = NULL;
+	self = (Bar*) foo_construct (object_type);
+	return self;
+}
+
+Bar*
+bar_new (void)
+{
+	return bar_construct (TYPE_BAR);
+}
+
+static void
+bar_class_init (BarClass * klass,
+                gpointer klass_data)
+{
+	bar_parent_class = g_type_class_peek_parent (klass);
+}
+
+static void
+bar_instance_init (Bar * self,
+                   gpointer klass)
+{
+}
+
+static GType
+bar_get_type_once (void)
+{
+	static const GTypeInfo g_define_type_info = { sizeof (BarClass), (GBaseInitFunc) NULL, (GBaseFinalizeFunc) NULL, (GClassInitFunc) bar_class_init, (GClassFinalizeFunc) NULL, NULL, sizeof (Bar), 0, (GInstanceInitFunc) bar_instance_init, NULL };
+	GType bar_type_id;
+	bar_type_id = g_type_register_static (TYPE_FOO, "Bar", &g_define_type_info, 0);
+	return bar_type_id;
+}
+
+GType
+bar_get_type (void)
+{
+	static volatile gsize bar_type_id__once = 0;
+	if (g_once_init_enter (&bar_type_id__once)) {
+		GType bar_type_id;
+		bar_type_id = bar_get_type_once ();
+		g_once_init_leave (&bar_type_id__once, bar_type_id);
+	}
+	return bar_type_id__once;
+}
+
+void
+manam (Foo** foos,
+       gint foos_length1)
+{
+	Foo* _tmp0_;
+	_tmp0_ = foos[0];
+	_vala_assert (IS_BAR (_tmp0_), "foos[0] is Bar");
+}
+
+static void
+_vala_main (void)
+{
+	Bar** bars = NULL;
+	Bar* _tmp0_;
+	Bar** _tmp1_;
+	gint bars_length1;
+	gint _bars_size_;
+	Foo** foos = NULL;
+	gint foos_length1;
+	gint _foos_size_;
+	Foo* _tmp2_;
+	_tmp0_ = bar_new ();
+	_tmp1_ = g_new0 (Bar*, 1 + 1);
+	_tmp1_[0] = _tmp0_;
+	bars = _tmp1_;
+	bars_length1 = 1;
+	_bars_size_ = bars_length1;
+	manam (bars, (gint) bars_length1);
+	foos = bars;
+	foos_length1 = bars_length1;
+	_foos_size_ = foos_length1;
+	_tmp2_ = foos[0];
+	_vala_assert (IS_BAR (_tmp2_), "foos[0] is Bar");
+	bars = (_vala_array_free (bars, bars_length1, (GDestroyNotify) foo_unref), NULL);
+}
+
+int
+main (int argc,
+      char ** argv)
+{
+	_vala_main ();
+	return 0;
+}
+
+static void
+_vala_array_destroy (gpointer array,
+                     gssize array_length,
+                     GDestroyNotify destroy_func)
+{
+	if ((array != NULL) && (destroy_func != NULL)) {
+		gssize i;
+		for (i = 0; i < array_length; i = i + 1) {
+			if (((gpointer*) array)[i] != NULL) {
+				destroy_func (((gpointer*) array)[i]);
+			}
+		}
+	}
+}
+
+static void
+_vala_array_free (gpointer array,
+                  gssize array_length,
+                  GDestroyNotify destroy_func)
+{
+	_vala_array_destroy (array, array_length, destroy_func);
+	g_free (array);
+}
+
diff --git a/tests/nullability/array-element-class.vala b/tests/nullability/array-element-class.vala
new file mode 100644
index 000000000..de6675055
--- /dev/null
+++ b/tests/nullability/array-element-class.vala
@@ -0,0 +1,18 @@
+class Foo {
+}
+
+class Bar : Foo {
+}
+
+void manam (Foo?[] foos) {
+	assert (foos[0] is Bar);
+}
+
+void main () {
+	Bar[] bars = { new Bar () };
+
+	manam (bars);
+
+	unowned Foo?[] foos = bars;
+	assert (foos[0] is Bar);
+}
diff --git a/tests/nullability/array-element-string.c-expected b/tests/nullability/array-element-string.c-expected
new file mode 100644
index 000000000..4ce699022
--- /dev/null
+++ b/tests/nullability/array-element-string.c-expected
@@ -0,0 +1,83 @@
+/* nullability_array_element_string.c generated by valac, the Vala compiler
+ * generated from nullability_array_element_string.vala, do not modify */
+
+#include <stdlib.h>
+#include <string.h>
+#include <glib.h>
+
+static void _vala_main (void);
+static void _vala_array_destroy (gpointer array,
+                          gssize array_length,
+                          GDestroyNotify destroy_func);
+static void _vala_array_free (gpointer array,
+                       gssize array_length,
+                       GDestroyNotify destroy_func);
+
+static void
+_vala_main (void)
+{
+	gchar** foos = NULL;
+	gchar* _tmp0_;
+	gchar* _tmp1_;
+	gchar** _tmp2_;
+	gint foos_length1;
+	gint _foos_size_;
+	_tmp0_ = g_strdup ("foo");
+	_tmp1_ = g_strdup ("bar");
+	_tmp2_ = g_new0 (gchar*, 2 + 1);
+	_tmp2_[0] = _tmp0_;
+	_tmp2_[1] = _tmp1_;
+	foos = _tmp2_;
+	foos_length1 = 2;
+	_foos_size_ = foos_length1;
+	{
+		gchar** bars = NULL;
+		gint bars_length1;
+		gint _bars_size_;
+		bars = foos;
+		bars_length1 = foos_length1;
+		_bars_size_ = bars_length1;
+	}
+	{
+		gchar** bars = NULL;
+		gint bars_length1;
+		gint _bars_size_;
+		bars = foos;
+		bars_length1 = foos_length1;
+		_bars_size_ = bars_length1;
+	}
+	foos = (_vala_array_free (foos, foos_length1, (GDestroyNotify) g_free), NULL);
+}
+
+int
+main (int argc,
+      char ** argv)
+{
+	_vala_main ();
+	return 0;
+}
+
+static void
+_vala_array_destroy (gpointer array,
+                     gssize array_length,
+                     GDestroyNotify destroy_func)
+{
+	if ((array != NULL) && (destroy_func != NULL)) {
+		gssize i;
+		for (i = 0; i < array_length; i = i + 1) {
+			if (((gpointer*) array)[i] != NULL) {
+				destroy_func (((gpointer*) array)[i]);
+			}
+		}
+	}
+}
+
+static void
+_vala_array_free (gpointer array,
+                  gssize array_length,
+                  GDestroyNotify destroy_func)
+{
+	_vala_array_destroy (array, array_length, destroy_func);
+	g_free (array);
+}
+
diff --git a/tests/nullability/array-element-string.vala b/tests/nullability/array-element-string.vala
new file mode 100644
index 000000000..a1d6221c9
--- /dev/null
+++ b/tests/nullability/array-element-string.vala
@@ -0,0 +1,9 @@
+void main () {
+	string[] foos = { "foo", "bar" };
+	{
+		unowned string?[] bars = foos;
+	}
+	{
+		unowned string?[]? bars = foos;
+	}
+}
diff --git a/vala/valaarraytype.vala b/vala/valaarraytype.vala
index a10bce502..59323331f 100644
--- a/vala/valaarraytype.vala
+++ b/vala/valaarraytype.vala
@@ -256,6 +256,12 @@ public class Vala.ArrayType : ReferenceType {
 		if (element_type.compatible (target_array_type.element_type)
 		    && target_array_type.element_type.compatible (element_type)) {
 			return true;
+		} else if (element_type.type_symbol is Class) {
+			unowned Class cl = (Class) element_type.type_symbol;
+			if ((!cl.is_compact || cl == context.analyzer.string_type.type_symbol)
+			    && element_type.compatible (target_array_type.element_type)) {
+				return true;
+			}
 		}
 
 		return false;