Noticed this while reviewing #13529, but it's also in master @ 5ba77df. On macOS 10.13.6:

<img width="209" alt="schermafbeelding 2018-08-01 om 16 22 09" src="https://user-images.githubusercontent.com/10217/43527498-0f571db4-95a7-11e8-8d90-7863947a7689.png">


<img width="178" alt="schermafbeelding 2018-08-01 om 16 12 51" src="https://user-images.githubusercontent.com/10217/43526994-c9a515ec-95a5-11e8-96b8-9e2513e9aac5.png">

* `Show` in the action menu doesn't work if the app was hidden by `Command + H`, it does work when hidden through this menu
* send and receive don't unhide the window when opened for the action menu. It does navigate to the right tab. The other actions do work (sign, verify & debug window)

Clicking "Toon" (= macOS native show) does work, suggesting the GUI uses some non-native method of hiding.
aboutAction->setEnabled(false);
    aboutQtAction = new QAction(platformStyle->TextColorIcon(":/icons/about_qt"), tr("About &Qt"), this);
    aboutQtAction->setStatusTip(tr("Show information about Qt"));
    aboutQtAction->setMenuRole(QAction::AboutQtRole);
    optionsAction = new QAction(platformStyle->TextColorIcon(":/icons/options"), tr("&Options..."), this);
    optionsAction->setStatusTip(tr("Modify configuration options for %1").arg(tr(PACKAGE_NAME)));
    optionsAction->setMenuRole(QAction::PreferencesRole);
    optionsAction->setEnabled(false);
    toggleHideAction = new QAction(platformStyle->TextColorIcon(":/icons/about"), tr("&Show / Hide"), this);
    toggleHideAction->setStatusTip(tr("Show or hide the main Window"));
    encryptWalletAction = new QAction(platformStyle->TextColorIcon(":/icons/lock_closed"), tr("&Encrypt Wallet..."), this);
    encryptWalletAction->setStatusTip(tr("Encrypt the private keys that belong to your wallet"));
    encryptWalletAction->setCheckable(true);
    backupWalletAction = new QAction(platformStyle->TextColorIcon(":/icons/filesave"), tr("&Backup Wallet..."), this);
    backupWalletAction->setStatusTip(tr("Backup wallet to another location"));
    changePassphraseAction = new QAction(platformStyle->TextColorIcon(":/icons/key"), tr("&Change Passphrase..."), this);
    changePassphraseAction->setStatusTip(tr("Change the passphrase used for wallet encryption"));
    signMessageAction = new QAction(platformStyle->TextColorIcon(":/icons/edit"), tr("Sign &message..."), this);
    signMessageAction->setStatusTip(tr("Sign messages with your Bitcoin addresses to prove you own them"));
    verifyMessageAction = new QAction(platformStyle->TextColorIcon(":/icons/verify"), tr("&Verify message..."), this);
    verifyMessageAction->setStatusTip(tr("Verify messages to ensure they were signed with specified Bitcoin addresses"));
    openRPCConsoleAction = new QAction(platformStyle->TextColorIcon(":/icons/debugwindow"), tr("&Debug window"), this);
    openRPCConsoleAction->setStatusTip(tr("Open debugging and diagnostic console"));
    
    openRPCConsoleAction->setEnabled(false);
    usedSendingAddressesAction = new QAction(platformStyle->TextColorIcon(":/icons/address-book"), tr("&Sending addresses..."), this);
    usedSendingAddressesAction->setStatusTip(tr("Show the list of used sending addresses and labels"));
    usedReceivingAddressesAction = new QAction(platformStyle->TextColorIcon(":/icons/address-book"), tr("&Receiving addresses..."), this);
    usedReceivingAddressesAction->setStatusTip(tr("Show the list of used receiving addresses and labels"));
    openAction = new QAction(platformStyle->TextColorIcon(":/icons/open"), tr("Open &URI..."), this);