diff --git a/mercurial/transaction.py b/mercurial/transaction.py
--- a/mercurial/transaction.py
+++ b/mercurial/transaction.py
@@ -414,6 +414,11 @@ class transaction(util.transactional):
         if vfs.exists(file):
             filepath = vfs.join(file)
             backuppath = vfs.join(backupfile)
+            # store encoding may result in different directory here.
+            # so we have to ensure the destination directory exist
+            final_dir_name = os.path.dirname(backuppath)
+            util.makedirs(final_dir_name, mode=vfs.createmode, notindexed=True)
+            # then we can copy the backup
             util.copyfile(filepath, backuppath, hardlink=hardlink)
         else:
             backupfile = b''
diff --git a/tests/test-transaction-rollback-on-revlog-split.t b/tests/test-transaction-rollback-on-revlog-split.t
--- a/tests/test-transaction-rollback-on-revlog-split.t
+++ b/tests/test-transaction-rollback-on-revlog-split.t
@@ -1,6 +1,9 @@
 Test correctness of revlog inline -> non-inline transition
 ----------------------------------------------------------
 
+We test various file length and naming pattern as this created issue in the
+past.
+
 Helper extension to intercept renames and kill process
 
   $ cat > $TESTTMP/intercept_before_rename.py << EOF
@@ -80,6 +83,7 @@ setup a repository for tests
   > file
   > Directory_With,Special%Char/Complex_File.babar
   > foo/bar/babar_celeste/foo
+  > 1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/1234567890/f
   > "
   $ for f in $files; do
   >     mkdir -p `dirname $f`
@@ -179,7 +183,7 @@ recover is rolling the split back, the f
   $ f -s .hg/store/data/file*
   .hg/store/data/file.i: size=1174
   $ hg tip
-  changeset:   1:272bd31be9b8
+  changeset:   1:cc8dfb126534
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
@@ -249,7 +253,7 @@ recover is rolling the split back, the f
   $ f -s .hg/store/data/file*
   .hg/store/data/file.i: size=1174
   $ hg tip
-  changeset:   1:272bd31be9b8
+  changeset:   1:cc8dfb126534
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
@@ -313,7 +317,7 @@ recover is rolling the split back, the f
   $ f -s .hg/store/data/file*
   .hg/store/data/file.i: size=1174
   $ hg tip
-  changeset:   1:272bd31be9b8
+  changeset:   1:cc8dfb126534
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
@@ -353,7 +357,7 @@ The split was rollback
 
 
   $ hg tip
-  changeset:   1:272bd31be9b8
+  changeset:   1:cc8dfb126534
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000