Frequently after one pull request is merged, multiple other pull requests follow to clean up a problem created by the first PR
Recent example: https://github.com/bitcoin/bitcoin/pull/7957
https://github.com/bitcoin/bitcoin/pull/8164 https://github.com/bitcoin/bitcoin/pull/8171
Normally no real harm is done. Is this no big deal or a sign that more testing should be done before Bitcoin pull requests are merged?