Form: set response content type when called directly

Form.__call__ replaces page template call, so it is also responsible
to set the content type in response.

With Page Templates, ZopePageTemplate._exec (called by
Shared.DC.Scripts.Bindings.__call__ and _bindAndExec) sets the
response content type and calls pt_render. Form.__call__ also calls
pt_render, so to behave like page template, it should also sets the
response content type.

In erp5_xhtml_style, we don't notice this, because global_definitions
contains a setHeader call to set content type to html.

bt5/erp5_core_test/TestTemplateItem/portal_components/test.erp5.testERP5Form.py

@@ -74,6 +74,11 @@ class TestERP5Form(ERP5TypeTestCase):
     self.assertTrue(self.form.formUnProxify())
     self.assertTrue(self.form.formShowRelatedProxyFields())
 
+  def test_publish_set_content_type(self):
+    resp = self.publish(self.form.getPath())
+    self.assertIn(b"test string field", resp.getBody())
+    self.assertEqual(resp.getHeader('Content-Type'), 'text/html; charset=utf-8')
+
 
 class TestProxify(ERP5TypeTestCase):
 

product/ERP5Form/Form.py

@@ -49,7 +49,7 @@ from AccessControl import Unauthorized, ClassSecurityInfo
 from DateTime import DateTime
 from ZODB.POSException import ConflictError
 from zExceptions import Redirect
-from Acquisition import aq_base
+from Acquisition import aq_base, aq_get
 from Products.PageTemplates.Expressions import SecureModuleImporter
 from zExceptions import Forbidden
 
@@ -676,7 +676,13 @@ class ERP5Form(Base, ZMIForm, ZopePageTemplate):
             raise AccessControl_Unauthorized('This document is not authorized for view.')
         else:
           container = None
-        pt = getattr(self,self.pt)
+        pt = getattr(self, self.pt)
+        request = aq_get(self, 'REQUEST', None)
+        if request is not None:
+            response = request.response
+            if 'content-type' not in response.headers:
+                response.setHeader('content-type', self.content_type)
+
         extra_context = dict( container=container,
                               template=self,
                               form=self,