libdpkg: Add new varbuf_add_archqual()

lib/dpkg/arch.c

@@ -29,6 +29,7 @@
 #include <dpkg/i18n.h>
 #include <dpkg/ehandle.h>
 #include <dpkg/dpkg-db.h>
+#include <dpkg/varbuf.h>
 #include <dpkg/arch.h>
 
 /**
@@ -172,3 +173,13 @@ dpkg_arch_reset_list(void)
 {
 	arch_item_any.next = NULL;
 }
+
+void
+varbuf_add_archqual(struct varbuf *vb, const struct dpkg_arch *arch)
+{
+	if (arch->type == arch_none)
+		return;
+
+	varbuf_add_char(vb, ':');
+	varbuf_add_str(vb, arch->name);
+}

lib/dpkg/arch.h

@@ -23,6 +23,7 @@
 #define LIBDPKG_ARCH_H
 
 #include <dpkg/macros.h>
+#include <dpkg/varbuf.h>
 
 DPKG_BEGIN_DECLS
 
@@ -46,6 +47,8 @@ struct dpkg_arch *dpkg_arch_get_native(void);
 struct dpkg_arch *dpkg_arch_get_list(void);
 void dpkg_arch_reset_list(void);
 
+void varbuf_add_archqual(struct varbuf *vb, const struct dpkg_arch *arch);
+
 DPKG_END_DECLS
 
 #endif /* LIBDPKG_ARCH_H */