diff -r 9bd60ec60601 -r 14b3dbfa4eeb mercurial/sparse.py
--- a/mercurial/sparse.py	Fri Jun 19 13:27:46 2020 +0200
+++ b/mercurial/sparse.py	Mon Sep 14 13:51:39 2020 +0530
@@ -399,7 +399,7 @@
             temporaryfiles.append(file)
             prunedactions[file] = action
         elif branchmerge:
-            if type != mergestatemod.ACTION_KEEP:
+            if type not in mergemod.mergeresult.NO_OP_ACTIONS:
                 temporaryfiles.append(file)
                 prunedactions[file] = action
         elif type == mergestatemod.ACTION_FORGET: