GHOST: exit with an error when GHOST cannot be initialized

When the GHOST back-end Blender was built with isn't supported,
Blender would crash on startup without any useful information.
This could happen when building X11 only, then running on Wayland.

Now show a list of the GHOST back-ends that were attempted and exit
with an error code instead of crashing.

2 files changed, 15 insertions, 0 deletions

diff --git a/source/blender/windowmanager/intern/wm_playanim.c b/source/blender/windowmanager/intern/wm_playanim.c
index bb19ba4748f..bf793ee41a0 100644
--- a/source/blender/windowmanager/intern/wm_playanim.c
+++ b/source/blender/windowmanager/intern/wm_playanim.c
@@ -1539,6 +1539,14 @@ static char *wm_main_playanim_intern(int argc, const char **argv)
     GHOST_SetBacktraceHandler((GHOST_TBacktraceFn)BLI_system_backtrace);
 
     g_WS.ghost_system = GHOST_CreateSystem();
+
+    if (UNLIKELY(g_WS.ghost_system == NULL)) {
+      /* GHOST will have reported the back-ends that failed to load. */
+      fprintf(stderr, "GHOST: unable to initialize, exiting!\n");
+      /* This will leak memory, it's preferable to crashing. */
+      exit(1);
+    }
+
     GHOST_AddEventConsumer(g_WS.ghost_system, consumer);
 
     playanim_window_open("Blender Animation Player", start_x, start_y, ibuf->x, ibuf->y);
diff --git a/source/blender/windowmanager/intern/wm_window.c b/source/blender/windowmanager/intern/wm_window.c
index 89bf2b82426..a4f92da2774 100644
--- a/source/blender/windowmanager/intern/wm_window.c
+++ b/source/blender/windowmanager/intern/wm_window.c
@@ -1546,6 +1546,13 @@ void wm_ghost_init(bContext *C)
 
   g_system = GHOST_CreateSystem();
 
+  if (UNLIKELY(g_system == NULL)) {
+    /* GHOST will have reported the back-ends that failed to load. */
+    fprintf(stderr, "GHOST: unable to initialize, exiting!\n");
+    /* This will leak memory, it's preferable to crashing. */
+    exit(1);
+  }
+
   GHOST_Debug debug = {0};
   if (G.debug & G_DEBUG_GHOST) {
     debug.flags |= GHOST_kDebugDefault;