notcurses_debug: handle bound planes

src/lib/debug.c

@@ -9,14 +9,14 @@ void notcurses_debug(notcurses* nc, FILE* debugfp){
     fprintf(debugfp, "%04d off y: %3d x: %3d geom y: %3d x: %3d curs y: %3d x: %3d %s %p\n",
             planeidx, n->absy, n->absx, n->leny, n->lenx, n->y, n->x,
             n == notcurses_stdplane_const(nc) ? "std" : "   ", n);
-    if(n->bound || n->bnext || *n->bprev){
+    if(n->bound || n->bnext || n->bprev){
       fprintf(debugfp, " bound to %p, next bound %p, bind %p\n",
-              n->bound, n->bnext, *n->bprev);
+              n->bound, n->bnext, n->bprev);
     }
     if(n->bnext == n || n->bound == n){
       fprintf(debugfp, "WARNING: bound pointers target self\n");
     }
-    if(*n->bprev != n){
+    if(n->bprev && (*n->bprev != n)){
       fprintf(stderr, " WARNING: expected *->bprev %p, got %p\n", n, *n->bprev);
     }
     if(n->above != prev){