From 31ff9f2f9ac07664086ca5c911c436fc42e638ef Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20P=C3=A9ters?= <fpeters@entrouvert.com>
Date: Mon, 24 Aug 2020 13:33:43 +0200
Subject: [PATCH] api: include first value for a repeated varname (#42468)

---
 tests/test_api.py | 65 +++++++++++++++++++++++++++++++++++++++++++++++
 wcs/formdata.py   |  7 +++++
 2 files changed, 72 insertions(+)

diff --git a/tests/test_api.py b/tests/test_api.py
index 8e1dd3cb8..d53e37883 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -1259,6 +1259,71 @@ def test_formdata_backoffice_fields(pub, local_user):
     assert resp.json['workflow']['fields']['backoffice_blah'] == 'Hello world'
 
 
+def test_formdata_duplicated_varnames(pub, local_user):
+    Role.wipe()
+    role = Role(name='test')
+    role.id = '123'
+    role.store()
+    another_role = Role(name='another')
+    another_role.id = '321'
+    another_role.store()
+    FormDef.wipe()
+    formdef = FormDef()
+    formdef.geolocations = {'base': 'blah'}
+    formdef.name = 'test'
+    formdef.fields = [
+        fields.StringField(id='0', label='foobar', varname='foobar'),
+        fields.StringField(id='1', label='foobar2', varname='foobar'),
+    ]
+    workflow = Workflow.get_default_workflow()
+    workflow.roles['_foobar'] = 'Foobar'
+    workflow.id = '2'
+    workflow.store()
+    formdef.workflow_id = workflow.id
+    formdef.workflow_roles = {'_receiver': role.id,
+                              '_foobar': another_role.id}
+    formdef.store()
+
+    formdef.data_class().wipe()
+    formdata = formdef.data_class()()
+    formdata.data = {
+        '0': 'foo',
+        '1': 'bar',
+    }
+    formdata.user_id = local_user.id
+    formdata.just_created()
+    formdata.status = 'wf-new'
+    formdata.evolution[-1].status = 'wf-new'
+    formdata.store()
+
+    local_user.roles = [role.id]
+    local_user.store()
+    resp = get_app(pub).get(
+            sign_uri('/api/forms/test/%s/' % formdata.id, user=local_user),
+            status=200)
+    assert resp.json['fields'] == {'foobar': 'foo'}
+
+    formdata.data = {
+        '0': 'foo',
+        '1': '',
+    }
+    formdata.store()
+    resp = get_app(pub).get(
+            sign_uri('/api/forms/test/%s/' % formdata.id, user=local_user),
+            status=200)
+    assert resp.json['fields'] == {'foobar': 'foo'}
+
+    formdata.data = {
+        '0': '',
+        '1': 'foo',
+    }
+    formdata.store()
+    resp = get_app(pub).get(
+            sign_uri('/api/forms/test/%s/' % formdata.id, user=local_user),
+            status=200)
+    assert resp.json['fields'] == {'foobar': 'foo'}
+
+
 def test_formdata_edit(pub, local_user):
     test_formdata(pub, local_user)
     formdef = FormDef.select()[0]
diff --git a/wcs/formdata.py b/wcs/formdata.py
index 17c35d341..f240af288 100644
--- a/wcs/formdata.py
+++ b/wcs/formdata.py
@@ -1025,17 +1025,24 @@ class FormData(StorableObject):
 
     def get_json_dict(self, fields, include_files=True, anonymise=False):
         new_data = {}
+        seen = set()
         for field in fields:
             if anonymise and field.anonymise:
                 continue
             if not field.varname:  # exports only named fields
                 continue
+            if field.varname in seen:
+                # skip fields with a varname that is used by another non-empty
+                # field.
+                continue
             if self.data is not None:
                 value = self.data.get(field.id)
                 if value and hasattr(field, 'get_json_value'):
                     value = field.get_json_value(value, formdata=self, include_file_content=include_files)
             else:
                 value = None
+            if value:
+                seen.add(field.varname)
             if field.store_display_value:
                 new_data[field.varname + '_raw'] = value
                 new_data[field.varname] = self.data.get('%s_display' % field.id)