issue 12 - DISPLAY=:0.-1 XtScreenDatabase segfault

Add a null-pointer check XtScreenDatabase(), exit if no display was opened.

Signed-off-by: Thomas E. Dickey <dickey@invisible-island.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/Initialize.c b/src/Initialize.c
index 13c5b2f..8ae54b4 100644
--- a/src/Initialize.c
+++ b/src/Initialize.c
@@ -542,6 +542,12 @@ XtScreenDatabase(Screen *screen)
     Display *dpy = DisplayOfScreen(screen);
 
     DPY_TO_APPCON(dpy);
+    if (dpy == NULL) {
+        XtErrorMsg("nullDisplay",
+                   "XtScreenDatabase", XtCXtToolkitError,
+                   "XtScreenDatabase requires a non-NULL display",
+                   NULL, NULL);
+    }
 
     LOCK_APP(app);
     LOCK_PROCESS;