manifestv2: disable fastdelta optimization We may add support for the fastdelta optimization for manifest v2 at a later point, but let's disable it for now, so we don't have to implement it right away.

manifestv2: add (unused) config option With tree manifests, hashes will change anyway, so now is a good time to also take up the old plans of a new manifest format. While there should be little or no reason to use tree manifests with the current manifest format (v1) once the new format (v2) is supported, we'll try to keep the two dimensions (flat/tree and v1/v2) separate. In preparation for adding a the new format, let's add configuration for it and propagate that configuration to the manifest revlog subclass. The new configuration ("experimental.manifestv2") says in what format to write the manifest data. We may later add other configuration to choose how to hash it, either keeping the v1 hash for BC or hashing the v2 content. See http://mercurial.selenic.com/wiki/ManifestV2Plan for more details.

manifest: extract method for creating manifest text Similar to the previous change, this one extracts a method for producing a manifest text from an iterator over (path, node, flags) tuples.

manifest: extract method for parsing manifest By extracting a method that generates (path, node, flags) tuples, we can reuse the code for parsing a manifest without doing it via a _lazymanifest like treemanifest currently does. It also prepares for parsing the new manifest format. Note that this makes parsing into treemanifest slower, since the parsing is now always done in pure Python. Since treemanifests will be expected (or even forced) to be used only with the new manifest format, parsing via _lazymanifest was not an option anyway.

dirstate._walkexplicit: don't bother normalizing '.' The overwhelmingly common case is running commands like 'hg diff' with no arguments. Therefore the only file that'll be listed is the root directory. Normalizing that's just a waste of time. This means that for a plain 'hg diff' we'll never need to construct the foldmap, saving us a significant chunk of time. On case-insensitive HFS+ on OS X, for a large repository with over 200,000 files, this brings down 'hg diff' from 2.97 seconds to 2.36.

dirstate._walkexplicit: drop normpath calls The paths the matcher returns are normalized already.

dirstate._walkexplicit: indicate root as '.', not '' '.' is the canonical way to represent the root, and it's apparently the only transformation that normpath makes.

phases: add killswitch for native implementation

phases: move pure phase computation in a function

revset: add hook after tree parsing This will be useful to execute actions after the tree is parsed and before the revset returns a match. Finding symbols in the parse tree will later allow hashes of hidden revisions to work on the command line without the --hidden flag.