--- a/hgext/largefiles/overrides.py	Sun Oct 16 02:26:38 2016 +0200
+++ b/hgext/largefiles/overrides.py	Sun Oct 16 02:29:45 2016 +0200
@@ -1390,7 +1390,8 @@
         lfdirstate = lfutil.openlfdirstate(repo.ui, repo)
         unsure, s = lfdirstate.status(matchmod.always(repo.root,
                                                     repo.getcwd()),
-                                      [], False, False, False)
+                                      [], False, True, False)
+        oldclean = set(s.clean)
         pctx = repo['.']
         for lfile in unsure + s.modified:
             lfileabs = repo.wvfs.join(lfile)
@@ -1402,9 +1403,13 @@
                                 lfutil.getexecutable(lfileabs))
             if (standin in pctx and
                 lfhash == lfutil.readstandin(repo, lfile, '.')):
-                lfdirstate.normal(lfile)
+                oldclean.add(lfile)
         for lfile in s.added:
             lfutil.updatestandin(repo, lfutil.standin(lfile))
+        # mark all clean largefiles as dirty, just in case the update gets
+        # interrupted before largefiles and lfdirstate are synchronized
+        for lfile in oldclean:
+            lfdirstate.normallookup(lfile)
         lfdirstate.write()
 
         oldstandins = lfutil.getstandinsstate(repo)
@@ -1413,6 +1418,13 @@
 
         newstandins = lfutil.getstandinsstate(repo)
         filelist = lfutil.getlfilestoupdate(oldstandins, newstandins)
+
+        # to avoid leaving all largefiles as dirty and thus rehash them, mark
+        # all the ones that didn't change as clean
+        for lfile in oldclean.difference(filelist):
+            lfdirstate.normal(lfile)
+        lfdirstate.write()
+
         if branchmerge or force or partial:
             filelist.extend(s.deleted + s.removed)
 

--- a/tests/test-largefiles-update.t	Sun Oct 16 02:26:38 2016 +0200
+++ b/tests/test-largefiles-update.t	Sun Oct 16 02:29:45 2016 +0200
@@ -732,16 +732,16 @@
 
 #endif
 
-Test a fatal error interrupting an update. lfdirstate doesn't realize that
-.hglf has been updated while the largefile hasn't. Status thus shows a clean
-state ... but rebuilding lfdirstate and checking all hashes reveals it isn't
-clean.
+Test a fatal error interrupting an update. Verify that status report dirty
+files correctly after an interrupted update. Also verify that checking all
+hashes reveals it isn't clean.
 
 Start with clean dirstates:
   $ hg up -qcr "8^"
   $ sleep 1
   $ hg st
-Update standins without updating largefiles:
+Update standins without updating largefiles - large1 is modified and largeX is
+added:
   $ cat << EOF > ../crashupdatelfiles.py
   > import hgext.largefiles.lfutil
   > def getlfilestoupdate(oldstandins, newstandins):
@@ -750,29 +750,31 @@
   > EOF
   $ hg up -Cr "8" --config extensions.crashupdatelfiles=../crashupdatelfiles.py
   [7]
-Check large1 content and status:
-BUG: largeX is R and large1 is not M and update does nothing
+Check large1 content and status ... and that update will undo modifications:
+BUG: large is R
   $ cat large1
   large1 in #3
   $ hg st
+  M large1
   R largeX
   $ hg up -Cr .
-  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  getting changed largefiles
+  1 largefiles updated, 0 removed
+  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cat large1
+  manually modified before 'hg transplant --continue'
   $ hg st
   R largeX
-Force largefiles rehashing and check again - revealing modifications that
-update now can remove:
+Force largefiles rehashing and check again - which makes it realize that largeX
+not has been removed but just doesn't exist:
   $ rm .hg/largefiles/dirstate
   $ hg st
-  M large1
   ! largeX
   $ hg up -Cr .
   getting changed largefiles
-  2 largefiles updated, 0 removed
-  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  1 largefiles updated, 0 removed
+  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg st
-  $ cat large1
-  manually modified before 'hg transplant --continue'
 
   $ cd ..