diff mercurial/cmdutil.py @ 45375:8c466bcb0879

revert: remove dangerous `parents` argument from `cmdutil.revert()`

As we found out the hard way (thanks to spectral@ for figuring it
out!), `cmdutil.revert()`'s `parents` argument must be
`repo.dirstate.parents()` or things may go wrong. We had an extension
that passed in the target commit as the first parent. The `hg split`
command from the evolve extension seems to have made the same mistake,
but I haven't looked carefully.

The problem is that `cmdutil._performrevert()` calls
`dirstate.normal()` on reverted files if the commit to revert to
equals the first parent. So if you pass in `ctx=foo` and
`parents=(foo.node(), nullid)`, then `dirstate.normal()` will be
called for the revert files, even though they might not be clean in
the working copy.

There doesn't seem to be any reason, other than a tiny performance
benefit, to passing the `parents` around instead of looking them up
again in `cmdutil._performrevert()`, so that's what this patch does.

Differential Revision: https://phab.mercurial-scm.org/D8925

--- a/mercurial/cmdutil.py	Mon Aug 10 18:08:15 2020 -0700
+++ b/mercurial/cmdutil.py	Mon Aug 10 21:46:47 2020 -0700
@@ -3493,9 +3493,9 @@
     return repo.status(match=scmutil.match(repo[None], pats, opts))
 
 
-def revert(ui, repo, ctx, parents, *pats, **opts):
+def revert(ui, repo, ctx, *pats, **opts):
     opts = pycompat.byteskwargs(opts)
-    parent, p2 = parents
+    parent, p2 = repo.dirstate.parents()
     node = ctx.node()
 
     mf = ctx.manifest()
@@ -3781,7 +3781,6 @@
             match = scmutil.match(repo[None], pats)
             _performrevert(
                 repo,
-                parents,
                 ctx,
                 names,
                 uipathfn,
@@ -3807,7 +3806,6 @@
 
 def _performrevert(
     repo,
-    parents,
     ctx,
     names,
     uipathfn,
@@ -3823,7 +3821,7 @@
 
     Make sure you have the working directory locked when calling this function.
     """
-    parent, p2 = parents
+    parent, p2 = repo.dirstate.parents()
     node = ctx.node()
     excluded_files = []