filemerge: stop returning always-`True` value

Now that we've removed some more leftovers from "merge driver", it's
clear that the first element of `filemerge()`'s return value is always
`True`.

Differential Revision: https://phab.mercurial-scm.org/D11885

hgext/largefiles/overrides.py

@@ -695,7 +695,7 b' def overridefilemerge('
         )
     ):
         repo.wwrite(fcd.path(), fco.data(), fco.flags())
-    return True, 0, False
+    return 0, False
 
 
 @eh.wrapfunction(copiesmod, b'pathcopies')

mercurial/filemerge.py

@@ -1031,7 +1031,7 b' def filemerge(repo, wctx, mynode, orig, '
     a boolean indicating whether the file was deleted from disk."""
 
     if not fco.cmp(fcd):  # files identical?
-        return True, None, False
+        return None, False
 
     ui = repo.ui
     fd = fcd.path()
@@ -1089,8 +1089,7 b' def filemerge(repo, wctx, mynode, orig, '
     toolconf = tool, toolpath, binary, symlink, scriptfn
 
     if mergetype == nomerge:
-        r, deleted = func(repo, mynode, fcd, fco, fca, toolconf, labels)
-        return True, r, deleted
+        return func(repo, mynode, fcd, fco, fca, toolconf, labels)
 
     if orig != fco.path():
         ui.status(
@@ -1109,7 +1108,7 b' def filemerge(repo, wctx, mynode, orig, '
                     b'in-memory merge does not support merge conflicts'
                 )
             ui.warn(onfailure % fduipath)
-        return True, 1, False
+        return 1, False
 
     backup = _makebackup(repo, ui, wctx, fcd)
     r = 1
@@ -1150,7 +1149,7 b' def filemerge(repo, wctx, mynode, orig, '
             )
             # we're done if premerge was successful (r is 0)
             if not r:
-                return not r, r, False
+                return r, False
 
         needcheck, r, deleted = func(
             repo,
@@ -1177,7 +1176,7 b' def filemerge(repo, wctx, mynode, orig, '
                 ui.warn(onfailure % fduipath)
             _onfilemergefailure(ui)
 
-        return True, r, deleted
+        return r, deleted
     finally:
         if not r and backup is not None:
             backup.remove()

mercurial/mergestate.py

@@ -354,7 +354,7 b' class _mergestate_base(object):'
             self._restore_backup(wctx[dfile], localkey, flags)
         else:
             wctx[dfile].remove(ignoremissing=True)
-        complete, merge_ret, deleted = filemerge.filemerge(
+        merge_ret, deleted = filemerge.filemerge(
             self._repo,
             wctx,
             self._local,
@@ -371,7 +371,6 b' class _mergestate_base(object):'
         elif not merge_ret:
             self.mark(dfile, MERGE_RECORD_RESOLVED)
 
-        if complete:
             action = None
             if deleted:
                 if fcd.isabsent():