Fix content-type POST conditions

POST conditions seem to be exclusive, so all conditions have to
match not only one of them. Therefore we need to remove the
condition if multiple content types are expected.

Author: codingjoe

s3file/forms.py

@@ -54,15 +54,12 @@ def get_conditions(self, accept):
             ["starts-with", "$key", self.upload_folder],
             {"success_action_status": "201"},
         ]
-        if accept:
-            accept = accept.replace(' ', '')  # remove whitespaces
-            mime_types = accept.split(',') if accept else []  # catch empty string
-            for mime_type in mime_types:
-                top_type, sub_type = mime_type.split('/', 1)
-                if sub_type == '*':
-                    conditions.append(["starts-with", "$Content-Type", "%s/" % top_type])
-                else:
-                    conditions.append({"Content-Type": mime_type})
+        if accept and ',' not in accept:
+            top_type, sub_type = accept.split('/', 1)
+            if sub_type == '*':
+                conditions.append(["starts-with", "$Content-Type", "%s/" % top_type])
+            else:
+                conditions.append({"Content-Type": accept})
         else:
             conditions.append(["starts-with", "$Content-Type", ""])
 

tests/test_forms.py

@@ -119,17 +119,11 @@ def test_accept(self):
 
         widget = ClearableFileInput(attrs={'accept': 'application/pdf,image/*'})
         assert 'accept="application/pdf,image/*"' in widget.render(name='file', value='test.jpg')
-        assert ["starts-with", "$Content-Type", "image/"] in widget.get_conditions(
+        assert ["starts-with", "$Content-Type", ""] in widget.get_conditions(
             'application/pdf,image/*')
-        assert {"Content-Type": 'application/pdf'} in widget.get_conditions(
+        assert {"Content-Type": 'application/pdf'} not in widget.get_conditions(
             'application/pdf,image/*')
 
-        widget = ClearableFileInput(attrs={'accept': 'application/pdf, image/*'})
-        assert 'accept="application/pdf, image/*"' in widget.render(name='file', value='test.jpg')
-        assert ["starts-with", "$Content-Type", "image/"] in widget.get_conditions(
-            'application/pdf, image/*')
-        assert {"Content-Type": 'application/pdf'} in widget.get_conditions(
-            'application/pdf, image/*')
 
     def test_no_js_error(self, driver, live_server):
         driver.get(live_server + self.url)