workflows: make sure model filenames are unique (#14096)

tests/test_workflow_import.py

@@ -211,6 +211,7 @@ def test_display_form_action():
 
 def test_export_to_model_action():
     wf = Workflow(name='status')
+    wf.store()
     st1 = wf.add_status('Status1', 'st1')
 
     from quixote.http_request import Upload
@@ -247,6 +248,16 @@ def test_export_to_model_action():
     wf2 = assert_import_export_works(wf)
     assert wf2.possible_status[0].items[0].model_file.get_file().read() == file_content
 
+    wf2 = assert_import_export_works(wf, include_id=True)
+    wf3 = assert_import_export_works(wf2, include_id=True)
+    assert wf2.possible_status[0].items[0].model_file.filename == \
+            wf3.possible_status[0].items[0].model_file.filename
+
+    wf3 = assert_import_export_works(wf2, include_id=False)
+    assert wf2.possible_status[0].items[0].model_file.filename != \
+            wf3.possible_status[0].items[0].model_file.filename
+
+
 def test_export_roles():
     wf = Workflow(name='roles')
     wf.roles = {'foo': 'Bar'}

wcs/wf/export_to_model.py

@@ -19,6 +19,7 @@ import collections
 from StringIO import StringIO
 from xml.etree import ElementTree as ET
 import zipfile
+import random
 import subprocess
 import tempfile
 import shutil
@@ -458,7 +459,11 @@ class ExportToModel(WorkflowStatusItem):
         if elem.find('content') is not None:
             content = elem.find('content').text
 
-        ids = (self.parent.parent.id, self.parent.id, self.id)
+        if self.parent.parent.id:
+            ids = (self.parent.parent.id, self.parent.id, self.id)
+        else:
+            # hopefully this will be random enough.
+            ids = ('i%i' % random.randint(0, 1000000), self.parent.id, self.id)
         filename = 'export_to_model-%s-%s-%s.upload' % ids
 
         upload = Upload(base_filename, content_type)