diff mercurial/merge.py @ 45518:32ce4cbaec4b

mergedriver: delete it

The merge driver code was added in late 2015. I think
'406a654b::6f045b56 & user("sid0")' is a reasonable revset for finding
the relevant commits, including preparation for it. The code is very
poorly tested, which makes it very hard to maintain. It seems it's
only used by FB and they don't use this code base anymore, so let's
remove the code to make it easier for us to maintain our product.

Differential Revision: https://phab.mercurial-scm.org/D9041

--- a/mercurial/merge.py	Sun Sep 06 10:33:12 2020 +0200
+++ b/mercurial/merge.py	Thu Sep 17 22:34:36 2020 -0700
@@ -355,20 +355,6 @@
         lastfull = f
 
 
-def driverpreprocess(repo, ms, wctx, labels=None):
-    """run the preprocess step of the merge driver, if any
-
-    This is currently not implemented -- it's an extension point."""
-    return True
-
-
-def driverconclude(repo, ms, wctx, labels=None):
-    """run the conclude step of the merge driver, if any
-
-    This is currently not implemented -- it's an extension point."""
-    return True
-
-
 def _filesindirs(repo, manifest, dirs):
     """
     Generator that yields pairs of all the files in the manifest that are found
@@ -1605,27 +1591,6 @@
             mergestatemod.ACTION_DIR_RENAME_MOVE_LOCAL,
         )
     )
-    # the ordering is important here -- ms.mergedriver will raise if the merge
-    # driver has changed, and we want to be able to bypass it when overwrite is
-    # True
-    usemergedriver = not overwrite and mergeactions and ms.mergedriver
-
-    if usemergedriver:
-        ms.commit()
-        proceed = driverpreprocess(repo, ms, wctx, labels=labels)
-        # the driver might leave some files unresolved
-        unresolvedf = set(ms.unresolved())
-        if not proceed:
-            # XXX setting unresolved to at least 1 is a hack to make sure we
-            # error out
-            return updateresult(
-                updated, merged, removed, max(len(unresolvedf), 1)
-            )
-        newactions = []
-        for f, args, msg in mergeactions:
-            if f in unresolvedf:
-                newactions.append((f, args, msg))
-        mergeactions = newactions
 
     try:
         # premerge
@@ -1655,18 +1620,6 @@
 
     unresolved = ms.unresolvedcount()
 
-    if (
-        usemergedriver
-        and not unresolved
-        and ms.mdstate() != mergestatemod.MERGE_DRIVER_STATE_SUCCESS
-    ):
-        if not driverconclude(repo, ms, wctx, labels=labels):
-            # XXX setting unresolved to at least 1 is a hack to make sure we
-            # error out
-            unresolved = max(unresolved, 1)
-
-        ms.commit()
-
     msupdated, msmerged, msremoved = ms.counts()
     updated += msupdated
     merged += msmerged
@@ -1674,9 +1627,6 @@
 
     extraactions = ms.actions()
     if extraactions:
-        mfiles = {
-            a[0] for a in mresult.getactions((mergestatemod.ACTION_MERGE,))
-        }
         for k, acts in pycompat.iteritems(extraactions):
             for a in acts:
                 mresult.addfile(a[0], k, *a[1:])
@@ -1684,27 +1634,6 @@
                 # no filedata until mergestate is updated to provide it
                 for a in acts:
                     getfiledata[a[0]] = None
-            # Remove these files from actions[ACTION_MERGE] as well. This is
-            # important because in recordupdates, files in actions[ACTION_MERGE]
-            # are processed after files in other actions, and the merge driver
-            # might add files to those actions via extraactions above. This can
-            # lead to a file being recorded twice, with poor results. This is
-            # especially problematic for actions[ACTION_REMOVE] (currently only
-            # possible with the merge driver in the initial merge process;
-            # interrupted merges don't go through this flow).
-            #
-            # The real fix here is to have indexes by both file and action so
-            # that when the action for a file is changed it is automatically
-            # reflected in the other action lists. But that involves a more
-            # complex data structure, so this will do for now.
-            #
-            # We don't need to do the same operation for 'dc' and 'cd' because
-            # those lists aren't consulted again.
-            mfiles.difference_update(a[0] for a in acts)
-
-        for a in list(mresult.getactions((mergestatemod.ACTION_MERGE,))):
-            if a[0] not in mfiles:
-                mresult.removefile(a[0])
 
     progress.complete()
     assert len(getfiledata) == (