[PATCH v2 2/2] ui: add precondition for dpy_get_ui_info()

[marcandre . lureau]

From: Marc-André Lureau <marcandre.lur...@redhat.com>

Ensure that it only get called when dpy_ui_info_supported(). The
function should always return a result. There should be a non-null
console or active_console.

Modify the argument to be const as well.

Signed-off-by: Marc-André Lureau <marcandre.lur...@redhat.com>
---
 include/ui/console.h | 2 +-
 ui/console.c         | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/ui/console.h b/include/ui/console.h
index 031e5d5194..08c0f0dc70 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -329,7 +329,7 @@ void update_displaychangelistener(DisplayChangeListener 
*dcl,
                                   uint64_t interval);
 void unregister_displaychangelistener(DisplayChangeListener *dcl);
 
-bool dpy_ui_info_supported(QemuConsole *con);
+bool dpy_ui_info_supported(const QemuConsole *con);
 const QemuUIInfo *dpy_get_ui_info(const QemuConsole *con);
 int dpy_set_ui_info(QemuConsole *con, QemuUIInfo *info, bool delay);
 
diff --git a/ui/console.c b/ui/console.c
index 0fbec4d0bd..1c710a6d5e 100644
--- a/ui/console.c
+++ b/ui/console.c
@@ -803,7 +803,7 @@ static void dpy_set_ui_info_timer(void *opaque)
     con->hw_ops->ui_info(con->hw, head, &con->ui_info);
 }
 
-bool dpy_ui_info_supported(QemuConsole *con)
+bool dpy_ui_info_supported(const QemuConsole *con)
 {
     if (con == NULL) {
         con = active_console;
@@ -817,6 +817,8 @@ bool dpy_ui_info_supported(QemuConsole *con)
 
 const QemuUIInfo *dpy_get_ui_info(const QemuConsole *con)
 {
+    assert(dpy_ui_info_supported(con));
+
     if (con == NULL) {
         con = active_console;
     }
-- 
2.41.0