core: Add pointer box / RAII impl

Signed-off-by: Ian Moffett <ian@mirocom.org>

core/state.c

@@ -33,6 +33,11 @@ state_init(struct cescal_state *state, const char *pathname)
         return -1;
     }
 
+    if (ptrbox_init(&state->ptrbox) < 0) {
+        close(state->in_fd);
+        return -1;
+    }
+
     return 0;
 }
 
@@ -41,4 +46,5 @@ state_close(struct cescal_state *state)
 {
     close(state->in_fd);
     state->in_fd = -1;
+    ptrbox_destroy(&state->ptrbox);
 }