Test that warnings apply to C files in Vala targets

test cases/failing build/1 vala c werror/meson.build

@@ -0,0 +1,10 @@
+project('valatest', 'c', default_options : 'werror=true')
+
+if find_program('valac', required : false).found()
+  add_languages('vala')
+  valadeps = [dependency('glib-2.0'), dependency('gobject-2.0')]
+  # Must fail due to -Werror and unused variable in C file
+  executable('valaprog', 'prog.vala', 'unused-var.c', dependencies : valadeps)
+else
+  executable('failprog', 'unused-var.c')
+endif

test cases/failing build/1 vala c werror/prog.vala

@@ -0,0 +1,7 @@
+class MainProg : GLib.Object {
+
+    public static int main(string[] args) {
+        stdout.printf("Vala is working.\n");
+        return 0;
+    }
+}

test cases/failing build/1 vala c werror/unused-var.c

@@ -0,0 +1,6 @@
+int
+somelib(void)
+{
+  int unused_var;
+  return 33;
+}