diff -r 058bb3dc685f -r 0b59724cb3f2 cubicweb/misc/scripts/repair_file_1-9_migration.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/misc/scripts/repair_file_1-9_migration.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,52 @@
+"""execute this script if you've migration to file >= 1.9.0 with cubicweb <= 3.9.2
+
+FYI, this migration occurred :
+* on our intranet on July 07 2010
+* on our extranet on July 16 2010
+"""
+from __future__ import print_function
+
+try:
+    backupinstance, = __args__
+except ValueError:
+    print('USAGE: cubicweb-ctl shell <instance> repair_file_1-9_migration.py -- <backup instance id>')
+    print()
+    print('you should restored the backup on a new instance, accessible through pyro')
+
+from cubicweb import cwconfig, dbapi
+from cubicweb.server.session import hooks_control
+
+defaultadmin = repo.config.default_admin_config
+backupcfg = cwconfig.instance_configuration(backupinstance)
+backupcfg.repairing = True
+backuprepo, backupcnx = dbapi.in_memory_repo_cnx(backupcfg, defaultadmin['login'],
+                                                 password=defaultadmin['password'],
+                                                 host='localhost')
+backupcu = backupcnx.cursor()
+
+with hooks_control(session, session.HOOKS_DENY_ALL):
+    rql('SET X is Y WHERE X is File, Y name "File", NOT X is Y')
+    rql('SET X is_instance_of Y WHERE X is File, Y name "File", NOT X is_instance_of Y')
+    for rtype, in backupcu.execute('DISTINCT Any RTN WHERE X relation_type RT, RT name RTN,'
+                                   'X from_entity Y, Y name "Image", X is CWRelation, '
+                                   'EXISTS(XX is CWRelation, XX relation_type RT, '
+                                   'XX from_entity YY, YY name "File")'):
+        if rtype in ('is', 'is_instance_of'):
+            continue
+        print(rtype)
+        for feid, xeid in backupcu.execute('Any F,X WHERE F %s X, F is IN (File,Image)' % rtype):
+            print('restoring relation %s between file %s and %s' % (rtype, feid, xeid), end=' ')
+            print(rql('SET F %s X WHERE F eid %%(f)s, X eid %%(x)s, NOT F %s X' % (rtype, rtype),
+                      {'f': feid, 'x': xeid}))
+
+    for rtype, in backupcu.execute('DISTINCT Any RTN WHERE X relation_type RT, RT name RTN,'
+                                   'X to_entity Y, Y name "Image", X is CWRelation, '
+                                   'EXISTS(XX is CWRelation, XX relation_type RT, '
+                                   'XX to_entity YY, YY name "File")'):
+        print(rtype)
+        for feid, xeid in backupcu.execute('Any F,X WHERE X %s F, F is IN (File,Image)' % rtype):
+            print('restoring relation %s between %s and file %s' % (rtype, xeid, feid), end=' ')
+            print(rql('SET X %s F WHERE F eid %%(f)s, X eid %%(x)s, NOT X %s F' % (rtype, rtype),
+                      {'f': feid, 'x': xeid}))
+
+commit()