unshelve: disable unshelve during merge (issue5123) As stated in the issue5123, unshelve can destroy the second parent of the context when tried to unshelve with an uncommitted merge. This patch makes unshelve to abort when called with an uncommitted merge. See how shelve.mergefiles works. Commit structure looks like this: ``` ... -> pctx -> tmpwctx -> shelvectx / / second merge parent pctx = parent before merging working context(first merge parent) tmpwctx = commited working directory after merge(with two parents) shelvectx = shelved context ``` shelve.mergefiles first updates to pctx then it reverts shelvectx to pctx with: ``` cmdutil.revert(ui, repo, shelvectx, repo.dirstate.parents(), *pathtofiles(repo, files), **{'no_backup': True}) ``` Reverting tmpwctx files that were merged from second parent to pctx makes them added because they are not in pctx. Changing this revert operation is crucial to restore parents after unshelve. This is a complicated issue as this is not fixing a regression. Thus, for the time being, unshelve during an uncommitted merge can be aborted. (Details taken from http://mercurial.808500.n3.nabble.com/PATCH-V3-shelve-restore-parents-after-unshelve-issue5123-tt4036858.html#a4037408) Differential Revision: https://phab.mercurial-scm.org/D6169

wix: add functionality to inject additional Features into installer This is the last bit required to be able to glue extra configs etc into the installer. Differential Revision: https://phab.mercurial-scm.org/D6180

wix: add support for additional wxs files As with my previous change for an --extra-prebuiild-script, I'm assuming this is predominantly useful in an enterprise environment and am only adding this to wix and not also to inno install scripts. Differential Revision: https://phab.mercurial-scm.org/D6179

wix: add a hook for a prebuild script to inject extra libraries I need this to build packages for Google so we can bundle some extensions in the installed image. My assumption is that this is most interesting for the .msi images so I only wired it up there. I'm not thrilled with the interface this provides, but it was an easy way to retain debug messages on Windows while also having enough structure to know what lines are actually module names for py2exe. Still pending on my end: I need to bundle a couple of config files, and at least one data file. I'm open to advice on how to do those things, and how to do this better. Differential Revision: https://phab.mercurial-scm.org/D6164

compression: introduce an official `format.revlog-compression` option This option supersedes the `experiment.format.compression` option. The value currently supported are zlib (default) and zstd (if Mercurial was compiled with zstd support). The option gained an explicit reference to `revlog` since this is the target usage here. Different storage methods might require different compression strategies. In our tests, using zstd give a significant CPU usage improvement (both compression and decompressing) while keeping similar repository size. Zstd as other interresting mode (dictionnary, pre-text, etc…) that are probably worth exploring. However, just plain switching from zlib to zstd provide a large benefit.

compression: display compression level in debugformat Now that we have options to control the compression level, we teach `hg debugformat` about them. This is a useful information when comparing repositories. Note that we have no trace of the compression level used to store existing deltas. Actually, it would even varies from one delta to another. So we display the currently set value.