shelve: let cmdutil.revert() take care of backing up untracked files cmdutil.revert() backs up untracked files, so I don't see a reason to do it shelve.mergefiles(). We have tests for this and they still pass. Differential Revision: https://phab.mercurial-scm.org/D6174

shelve: stop passing list of files to revert It seems to work just fine to not specify any files here. I suspect it looked the way it did for historical reasons. It apparently used to use merge instead of rebase until 1d7a36ff2615 (shelve: use rebase instead of merge (issue4068), 2013-10-23) and it makes sense to want to restrict the set of files then. I noticed this because of the files.extend(shelvectx.p1().files()). If the working copy was clean before, then shelvectx.p1() will be the working copy parent and that ended up adding all the files in that set. In our Google-internal Mercurial setup (including a FUSE) that was very noticeably slow when the working copy parent happened to have many files in large directories. This patch doesn't yet remove the call to shelvectx.p1().files(). We also use that set for deciding what to back up. I'm pretty sure it's safe to back up only the set of files we already back even if we no longer restrict the set of files to revert, so this patch should be safe on its own. Regardless, the next patch will delegate the backing-up to cmdutil.revert(). Incidentally, this also gets rid of a repo.pathto() that I had earlier wanted to get rid of. Differential Revision: https://phab.mercurial-scm.org/D6173

remotefilelog: prefetch files in deterministic order I have been troubleshooting some slowness in this area (it's unclear if it's the client or server that's to blame, but that's beside the point) and it's a lot easier to do troubleshoot if the files are prefetched in the same order each time. Differential Revision: https://phab.mercurial-scm.org/D6172

debugdiscovery: display time elapsed during the discovery step This is a useful information. Now that we perform more analysing after the discovery is done, it is worth have a more precise measurement. For serious timing analysis use `hg perfdiscovery`.

debugdiscovery: only list common heads on verbose The list of common heads is only part of the useful information. In addition on repository with many heads, the information is very not helpful (just fill a couple of screen with hash). As a result we hide it behind a --verbose flag.

debugdiscovery: drop duplicated information The old line informing about the local being a superset or subset of the remote is redundant with the newly introduced data. So we drop it.

debugdiscovery: display more statistic about the common set We display a lot more information now. Especially, we display the overlap between the common heads and the local/remote heads. There are various optimization geared toward heads, as a result, the less common the heads the more complex the discovery. Having this information easily accessible help when working on discovery.

debugdiscovery: small internal refactoring The part of the code displaying statistic is made independant from the one running the discovery. In the same do, the declaration of the discovery function is a bit simplified.

debugdiscovery: allow to select random seed during debugdiscovery run The randomness can lead to large timing difference, controling it is important.

discovery: move cl.hasnode outside of the for-loop IIUC, resolving attributes for changelog can lead to some overhead. So this patch moves that to outside of a for-loop. Differential Revision: https://phab.mercurial-scm.org/D6147

discovery: prevent deleting items from a dictionary Removing elements from Python dictionary is expensive. So let's prevent adding them instead. I added a newline to make code look a bit better. Differential Revision: https://phab.mercurial-scm.org/D6146

discovery: drop some unused sets Differential Revision: https://phab.mercurial-scm.org/D6145

discovery: prevent recomputing info about server and outgoing changesets We already iterate over the outgoing.missing above and lookup repo for them. So let's reuse info calculated at that time instead of recomputing that again. Also we calculate the set of remotebranches by doing set(remotemap), so let's reuse that again. Upcoming patches will clean things a bit more. Differential Revision: https://phab.mercurial-scm.org/D6144

crecord: draw on the whole screen When starting crecord, one can see that it has a small gap on the rightmost column which doesn't get used. This is in contrast to other interactive curses frontends such as chistedit. Disabling the displaying of the cursor allows drawing on the whole availabe area and thus some hacky code in align() could be removed. Differential Revision: https://phab.mercurial-scm.org/D6171

automation: perform tasks on remote machines Sometimes you don't have access to a machine in order to do something. For example, you may not have access to a Windows machine required to build Windows binaries or run tests on that platform. This commit introduces a pile of code intended to help "automate" common tasks, like building release artifacts. In its current form, the automation code provides functionality for performing tasks on Windows EC2 instances. The hgautomation.aws module provides functionality for integrating with AWS. It manages EC2 resources such as IAM roles, EC2 security groups, AMIs, and instances. The hgautomation.windows module provides a higher-level interface for performing tasks on remote Windows machines. The hgautomation.cli module provides a command-line interface to these higher-level primitives. I attempted to structure Windows remote machine interaction around Windows Remoting / PowerShell. This is kinda/sorta like SSH + shell, but for Windows. In theory, most of the functionality is cloud provider agnostic, as we should be able to use any established WinRM connection to interact with a remote. In reality, we're tightly coupled to AWS at the moment because I didn't want to prematurely add abstractions for a 2nd cloud provider. (1 was hard enough to implement.) In the aws module is code for creating an image with a fully functional Mercurial development environment. It contains VC9, VC2017, msys, and other dependencies. The image is fully capable of building all the existing Mercurial release artifacts and running tests. There are a few things that don't work. For example, running Windows tests with Python 3. But building the Windows release artifacts does work. And that was an impetus for this work. (Although we don't yet support code signing.) Getting this functionality to work was extremely time consuming. It took hours debugging permissions failures and other wonky behavior due to PowerShell Remoting. (The permissions model for PowerShell is crazy and you brush up against all kinds of issues because of the user/privileges of the user running the PowerShell and the permissions of the PowerShell session itself.) The functionality around AWS resource management could use some improving. In theory we support shared tenancy via resource name prefixing. In reality, we don't offer a way to configure this. Speaking of AWS resource management, I thought about using a tool like Terraform to manage resources. But at our scale, writing a few dozen lines of code to manage resources seemed acceptable. Maybe we should reconsider this if things grow out of control. Time will tell. Currently, emphasis is placed on Windows. But I only started there because it was likely to be the most difficult to implement. It should be relatively trivial to automate tasks on remote Linux machines. In fact, I have a ~1 year old script to run tests on a remote EC2 instance. I will likely be porting that to this new "framework" in the near future. # no-check-commit because foo_bar functions Differential Revision: https://phab.mercurial-scm.org/D6142

contrib: PowerShell script to install development dependencies Configuring a Windows machine to hack on Mercurial is a bit of work and it isn't documented very well. This commit introduces a PowerShell script to automate going from a fresh Windows install to an environment suitable for building Mercurial, its installers, and running tests. Differential Revision: https://phab.mercurial-scm.org/D6141