[evolution-data-server] _libedataserverui_init_icon_theme: Test whether default GdkScreen exists

[Milan Crha <mcrha src gnome org>]

commit 237eaecb778e041a69641a578ab6e32c4f82a6a8
Author: Milan Crha <mcrha redhat com>
Date:   Wed Dec 1 18:35:33 2021 +0100

    _libedataserverui_init_icon_theme: Test whether default GdkScreen exists
    
    It does not exist when building developer documentation, which causes
    a runtime warning from the gtk+ code, thus test it before calling
    gtk_icon_theme_get_default().

 src/libedataserverui/libedataserverui-private.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/src/libedataserverui/libedataserverui-private.c b/src/libedataserverui/libedataserverui-private.c
index e303a87c2..0c6615d91 100644
--- a/src/libedataserverui/libedataserverui-private.c
+++ b/src/libedataserverui/libedataserverui-private.c
@@ -61,7 +61,8 @@ _libedataserverui_init_icon_theme (void)
 {
        static gboolean icons_added = FALSE;
 
-       if (!icons_added) {
+       /* The screen can be NULL when building the documentation */
+       if (!icons_added && gdk_screen_get_default ()) {
                icons_added = TRUE;
 
                gtk_icon_theme_append_search_path (gtk_icon_theme_get_default (), E_DATA_SERVER_ICONDIR);