命令 "aptitude upgrade" 是在 Debian 上执行完全升级还是安全升级?

Does the command "aptitude upgrade" perform a full-upgrade or a safe-upgrade on Debian?

命令 aptitude full-upgradeaptitude safe-upgrade 都是 documented,包括 full-upgradedist-upgrade 别名。

但是,简单地 aptitude upgrade 也会以某种方式升级系统...它默认为哪个?另外我怎么会为自己找到这个? man aptitude upgrade 没有帮助。

source-code(但不是文档)中可以看出,upgrade 确实是 safe-upgrade:

的别名
else if(!strcasecmp(argv[0], "full-upgrade") ||
  !strcasecmp(argv[0], "dist-upgrade"))
{
   default_action = cmdline_upgrade;
   // [...]
   upgrade_mode = full_upgrade;
   // [...]
   resolver_mode = resolver_mode_full;
}
else if(!strcasecmp(argv[0], "safe-upgrade") ||
  !strcasecmp(argv[0], "upgrade"))
{
   default_action = cmdline_upgrade;
   // [...]
   upgrade_mode = safe_upgrade;
   // [...]
   resolver_mode = resolver_mode_safe;
}