histedit: drop fallback to empty string from rendertemplate() AFAICT, `cmdutil.rendertemplate()` always returns bytes (never e.g. `None`), so we don't need to fall back to empty (byte-)string. The fallback has been there since the code was added in 11c076786d56 (histedit: add templating support to histedit's rule file generation, 2019-01-29). Differential Revision: https://phab.mercurial-scm.org/D9244

phases: convert registernew users to use revision sets Differential Revision: https://phab.mercurial-scm.org/D9233

phases: allow registration and boundary advancement with revision sets The core internals either use revision sets already or can trivially use them. Use the new interface in cg1unpacker.apply to avoid materializing the list of all new nodes as it is normally just a revision range. This avoids about 67 Bytes / changeset on AMD64 in peak RSS. Differential Revision: https://phab.mercurial-scm.org/D9232

revlog: extend addgroup() with callback for duplicates The addgroup() interface currently doesn't allow the caller to keep track of duplicated nodes except by looking at the returned node list. Add an optional second callback for this purpose and change the return type to a boolean. This allows follow-up changes to use more efficient storage for the node list in places that are memory-sensitive. Differential Revision: https://phab.mercurial-scm.org/D9231

tags: add safety check for len(record) while reading hgtagsfnodescache I am trying to fix a breakage where somehow we end up getting a node of 12 length from `getfnode()`. Understanding the hgtagsfnodescache code, it seems highly unlikely that it can happen unless one of `mctx.readfast().get()` or `ctx.filenode()` is returning a node of 12 length. For safety, I think it's better to add a check to make sure that record which we are parsing is of same length we are expecting otherwise we consider that as invalid record. Differential Revision: https://phab.mercurial-scm.org/D9169

procutil: allow to specify arbitrary stdin bytes to runbgcommand For automatic clonebundles generation I need to pass arbitrary large amount of data to the process (eg: common nodes, target nodes). I am updating the `runbgcommand` to allow for this. Previously not stdin input was possible, now, one can provide raw bytes and they will be feed to the command through an unnamed temporary files. Differential Revision: https://phab.mercurial-scm.org/D9212

clonebundle: move the manifest filename to a constant I am about to add more reference to it, so I would rather have it an explicit constant. This allow to unify various call too. Differential Revision: https://phab.mercurial-scm.org/D9209