@jonasschnelli wrote in #14979:
> #14573 broke < Qt5.6 compatibility due to calling the lambda version of `addAction` that was added in Qt5.6.

We currently [support](https://github.com/bitcoin/bitcoin/blob/master/doc/dependencies.md) QT >=5.2, but hardly anyone tests with that. If we make one of the Travis machines use it, we should have a better change of catching this.

See also discussion about minimum QT version in #13478 
{
    
    CWallet* pwallet = wallet.get();
    {
        LOCK(g_wallet_release_mutex);
        auto it = g_unloading_wallet_set.insert(pwallet);
        assert(it.second);
    }
    
    
    
    pwallet->NotifyUnload();
    
    wallet.reset();
    {
        WAIT_LOCK(g_wallet_release_mutex, lock);
        while (g_unloading_wallet_set.count(pwallet) == 1) {
            g_wallet_release_cv.wait(lock);
        }
    }
}
const uint32_t BIP32_HARDENED_KEY_LIMIT = 0x80000000;
const uint256 CMerkleTx::ABANDON_HASH(uint256S("0000000000000000000000000000000000000000000000000000000000000001"));
/** @defgroup mapWallet
 *
 * @{
 */
std::string COutput::ToString() const