We're currently using crucible but are evaluating stash, when a merge results in conflicts we upload the conflict resolution as a pre-commit generated by git show -m --no-prefix -w -U20 {merge-commit} -- {list of conflicted files}.
We use -m so that we can review whether or not the merger kept the correct conflicting version (by default git show / git diff excludes conflicts where one of the conflicting versions was kept without other alterations).
How does stash deal with or avoid this situation in a pull request?