comparison hgext/fix.py @ 40570:ad71c792a8d8

fix: add extra field to fixed revisions to avoid creating obsolescence cycles

The extra field prevents sequential invocations of fix from producing the same
hash twice. Previously, this could cause problems because it would create an
obsolescence cycle instead of the expected new successor.

This change also adds an explicit check for whether a new revision should be
committed. Until now, the code relied on memctx.commit() to quietly do nothing
if the node already exists. Because of the new extra field, this no longer
covers the case where we don't want to replace an unchanged node.

Differential Revision: https://phab.mercurial-scm.org/D5245

40569:19e1c26213f1

    p1rev, p2rev = repo.changelog.parentrevs(ctx.rev())
    p1ctx, p2ctx = repo[p1rev], repo[p2rev]
    newp1node = replacements.get(p1ctx.node(), p1ctx.node())
    newp2node = replacements.get(p2ctx.node(), p2ctx.node())

    def filectxfn(repo, memctx, path):
        if path not in ctx:
            return None
        fctx = ctx[path]
        copied = fctx.renamed()

            data=filedata.get(path, fctx.data()),
            islink=fctx.islink(),
            isexec=fctx.isexec(),
            copied=copied)

    memctx = context.memctx(
        repo,
        parents=(newp1node, newp2node),
        text=ctx.description(),
        files=set(ctx.files()) | set(filedata.keys()),
        filectxfn=filectxfn,
        user=ctx.user(),
        date=ctx.date(),
        extra=ctx.extra(),
        branch=ctx.branch(),
        editor=None)
    sucnode = memctx.commit()
    prenode = ctx.node()
    if prenode == sucnode:

40570:ad71c792a8d8

    p1rev, p2rev = repo.changelog.parentrevs(ctx.rev())
    p1ctx, p2ctx = repo[p1rev], repo[p2rev]
    newp1node = replacements.get(p1ctx.node(), p1ctx.node())
    newp2node = replacements.get(p2ctx.node(), p2ctx.node())

    # We don't want to create a revision that has no changes from the original,
    # but we should if the original revision's parent has been replaced.
    # Otherwise, we would produce an orphan that needs no actual human
    # intervention to evolve. We can't rely on commit() to avoid creating the
    # un-needed revision because the extra field added below produces a new hash
    # regardless of file content changes.
    if (not filedata and
        p1ctx.node() not in replacements and
        p2ctx.node() not in replacements):
        return

    def filectxfn(repo, memctx, path):
        if path not in ctx:
            return None
        fctx = ctx[path]
        copied = fctx.renamed()

            data=filedata.get(path, fctx.data()),
            islink=fctx.islink(),
            isexec=fctx.isexec(),
            copied=copied)

    extra = ctx.extra().copy()
    extra['fix_source'] = ctx.hex()

    memctx = context.memctx(
        repo,
        parents=(newp1node, newp2node),
        text=ctx.description(),
        files=set(ctx.files()) | set(filedata.keys()),
        filectxfn=filectxfn,
        user=ctx.user(),
        date=ctx.date(),
        extra=extra,
        branch=ctx.branch(),
        editor=None)
    sucnode = memctx.commit()
    prenode = ctx.node()
    if prenode == sucnode: