diff --git a/mercurial/filemerge.py b/mercurial/filemerge.py
--- a/mercurial/filemerge.py
+++ b/mercurial/filemerge.py
@@ -341,7 +341,8 @@
                 labels = _defaultconflictlabels
             if len(labels) < 3:
                 labels.append('base')
-        r = simplemerge.simplemerge(ui, a, b, c, quiet=True, label=labels)
+        r = simplemerge.simplemerge(ui, a, b, c, fcd, fca, fco,
+                                    quiet=True, label=labels, repo=repo)
         if not r:
             ui.debug(" premerge successful\n")
             return 0
@@ -371,7 +372,8 @@
 
     ui = repo.ui
 
-    r = simplemerge.simplemerge(ui, a, b, c, label=labels, mode=mode)
+    r = simplemerge.simplemerge(ui, a, b, c, fcd, fca, fco,
+                                label=labels, mode=mode, repo=repo)
     return True, r, False
 
 @internaltool('union', fullmerge,
@@ -423,8 +425,9 @@
     assert localorother is not None
     tool, toolpath, binary, symlink = toolconf
     a, b, c, back = files
-    r = simplemerge.simplemerge(repo.ui, a, b, c, label=labels,
-                                localorother=localorother)
+    r = simplemerge.simplemerge(repo.ui, a, b, c, fcd, fca, fco,
+                                label=labels, localorother=localorother,
+                                repo=repo)
     return True, r
 
 @internaltool('merge-local', mergeonly, precheck=_mergecheck)