GUI update overhead when selecting parent in coin control #7108

When selecting a parent in coin control tree mode. updateLabels is called for every child. Unlike when using select/deselect all. updateLabels is only called once. I am trying to figure this out on my own, but any guidance toward making the changes and pull request would be great.

During the time that updateLabels is being continuously called. The length of each loop increases, and it keeps the QT in a locked state while doing so. Causing an increased cpu usage. And for some users with lower end pc's, a crash. Heres a log with some timers on the functions. selecting 300 inputs at a time. http://pastebin.com/SQtJidHy

Except from the PasteBin link:

2015-11-27 00:56:14 CoinControlDialog::updateLabels() - Time elapsed: 0.188000
2015-11-27 00:56:14 CoinControlDialog::viewItemChanged() - Time elapsed: 0.188000

2015-11-27 00:56:15 CoinControlDialog::updateLabels() - Time elapsed: 0.187000
2015-11-27 00:56:15 CoinControlDialog::viewItemChanged() - Time elapsed: 0.187000

2015-11-27 00:56:15 CoinControlDialog::updateLabels() - Time elapsed: 0.186000
2015-11-27 00:56:15 CoinControlDialog::viewItemChanged() - Time elapsed: 0.187000

2015-11-27 00:56:15 CoinControlDialog::updateLabels() - Time elapsed: 0.185000
2015-11-27 00:56:15 CoinControlDialog::viewItemChanged() - Time elapsed: 0.186000

2015-11-27 00:56:15 CoinControlDialog::updateLabels() - Time elapsed: 0.185000
2015-11-27 00:56:15 CoinControlDialog::viewItemChanged() - Time elapsed: 0.185000

2015-11-27 00:56:15 CoinControlDialog::updateLabels() - Time elapsed: 0.189000
2015-11-27 00:56:15 CoinControlDialog::viewItemChanged() - Time elapsed: 0.190000

2015-11-27 00:56:16 CoinControlDialog::updateLabels() - Time elapsed: 0.186000
2015-11-27 00:56:16 CoinControlDialog::viewItemChanged() - Time elapsed: 0.186000

2015-11-27 00:56:16 CoinControlDialog::updateLabels() - Time elapsed: 0.189000
2015-11-27 00:56:16 CoinControlDialog::viewItemChanged() - Time elapsed: 0.189000

2015-11-27 00:56:16 CoinControlDialog::updateLabels() - Time elapsed: 0.187000
2015-11-27 00:56:16 CoinControlDialog::viewItemChanged() - Time elapsed: 0.188000

2015-11-27 00:56:16 CoinControlDialog::updateLabels() - Time elapsed: 0.186000
2015-11-27 00:56:16 CoinControlDialog::viewItemChanged() - Time elapsed: 0.186000

2015-11-27 00:56:16 CoinControlDialog::viewItemChanged() - Time elapsed: 0.000000

2015-11-27 00:56:16 CoinControlDialog::viewItemChanged() - Time elapsed: 57.793000

scroll up to the top of the pastebin where the loop started. 2015-11-27 00:54:49 CoinControlDialog::updateLabels() - Time elapsed: 0.001000 2015-11-27 00:54:49 CoinControlDialog::viewItemChanged() - Time elapsed: 0.001000 also when the number of inputs hits 500+ the delay starts to increase again. I'll create another pastebin for reference, that is a bit better displayed. with a total of 1679 tx's. once it finally completes... EDIT: http://pastebin.com/9M5h1c6n

Is this still an issue with a recent version of Bitcoin Core? If yes, what are the steps to reproduce?

I tried with 3000 inputs and it took 3 seconds.