Mercurial uses hg backout to start a new commit that backs out a previous commit, hg rollback to undo the previous transaction (without a separate commit), and hg revert does undoes the uncommitted changes in your working directory, very similar to MS Word's (now defunct) and Photoshop's (still active) File > Revert command.
To me, revert means "revert all my changes to the last saved version", which is exactly what Hg does.
I had another sentence in my post that I edited out that was a caveat to Mercurial: at least it's possible to get the 'git revert' behavior with hg without implementing it yourself from a patch-series dump.
To me, revert means "stage a new commit that reverts this commit in the history as if it never existed".
When I first used svn, I really expected 'revert' to mean "revert this commit". I also 'intuitively' expected it to have something like git's index, and ended up just working around that by just laboriously creating my own set of patches to feed it in another checkout. Not everyone's mental models line up — we are both free to consider one another as a moron (see also: politics, religion).
Mercurial uses hg backout to start a new commit that backs out a previous commit, hg rollback to undo the previous transaction (without a separate commit), and hg revert does undoes the uncommitted changes in your working directory, very similar to MS Word's (now defunct) and Photoshop's (still active) File > Revert command.
To me, revert means "revert all my changes to the last saved version", which is exactly what Hg does.