if(!ctx) return;
void mx_fastclose_mailbox (CONTEXT *ctx){  int i;  #ifdef USE_IMAP  if (ctx->magic == M_IMAP)    imap_fastclose_mailbox (ctx);#endif /* USE_IMAP */  if (ctx->subj_hash)    hash_destroy (&ctx->subj_hash, NULL);  if (ctx->id_hash)    hash_destroy (&ctx->id_hash, NULL);  for (i = 0; i < ctx->msgcount; i++)    mutt_free_header (&ctx->hdrs[i]);  safe_free ((void **) &ctx->hdrs);  safe_free ((void **) &ctx->v2r);  safe_free ((void **) &ctx->path);  safe_free ((void **) &ctx->pattern);  if (ctx->limit_pattern)     mutt_pattern_free (&ctx->limit_pattern);  if (ctx->fp)    fclose (ctx->fp);  memset (ctx, 0, sizeof (CONTEXT));}