revlog: introduce an explicit `format_version` member in the index struct This will allow for cleaner check than assuming each version has a different size. Unsurprisingly I am planning to use this to introduce more format variant. Differential Revision: https://phab.mercurial-scm.org/D10567

revlog: rename `hdrsize` to `entry_size` in the C code This is the size of and index entry, so lets make it clearer. Differential Revision: https://phab.mercurial-scm.org/D10566

revlog: split the `version` attribute into its two components The `revlog.version` attribute contained an integer coding 2 different informations: * the revlog version number * a bit field defining some specific feature of the revlog We now explicitly store the two components independently. This avoid exposing the implementation details all around the code and prepare for future revlog version that would encode the information in a different way. In the process we drop the `version` attribute from the interface. It was flagged for removal when that interface was created. Differential Revision: https://phab.mercurial-scm.org/D10565

verify: pass a revlog to `_checkrevlog` in `_verifymanifest` Since `manifestrevlog` is not a `revlog`, we are passing strange thing to `_checkrevlog`. We fix this to avoid breakage during future change. Differential Revision: https://phab.mercurial-scm.org/D10564

revlog: replace flag check related to generaldelta with attribute check Same logic as the previous changesets. Differential Revision: https://phab.mercurial-scm.org/D10563

revlog: replace REVLOGV2 check related to sidedata with `hassidedata` checks This is more flexible and semantically more correct. The associated revlog's attribute exist since 827cb4fe62a3, so well we start linking sidedata to revlogv2. Differential Revision: https://phab.mercurial-scm.org/D10562

revlog: explicitely pass the "indexfile" parameter Most of this was already done when introducing the `target` parameter, but some remained. Having "indexfile" passed explicitely will help us to change the way we address a revlog later in the stack. With the introduction of more generic `docket`, the entry point will not necessarly be `xxx.i` file, and the actual index files will have a variable name. Differential Revision: https://phab.mercurial-scm.org/D10561

revlog: highlight current incompatibility in `rewrite_sidedata` See comment for details. We will need to fix the test coverage when this incompatibility is lifted. Differential Revision: https://phab.mercurial-scm.org/D10544

revlog: adjust rewrite_sidedata code to not delete existing revlog content The "w+" file mode is deleting all the content of the opened file. Which is bad… This is not caught by the test because the test only check for a full, initial pull where not pre-existing content exists. So we need to fix our test coverage here. However they are another issue that prevent "incremental" pull to work here. See next changeset for details. Differential Revision: https://phab.mercurial-scm.org/D10543

status: Add tests for some more edge cases * Size-preserving file contents modification * Filtering output to a deleted or removed file Differential Revision: https://phab.mercurial-scm.org/D10701