wscalls: unflatten payload when calling webservice (#66916)

tests/workflow/test_wscall.py

@@ -591,12 +591,12 @@ def test_webservice_with_unflattened_payload_keys(http_requests, pub):
 
     item = WebserviceCallStatusItem()
     item.url = 'http://remote.example.net'
-    item.post_data = {'foo/0': 'first', 'foo/1': 'second', 'bar': 'example'}
+    item.post_data = {'foo/0': 'first', 'foo/1': 'second', 'bar': 'example', 'random//field': 'value'}
     item.perform(formdata)
     assert http_requests.get_last('url') == 'http://remote.example.net/'
     assert http_requests.get_last('method') == 'POST'
     payload = json.loads(http_requests.get_last('body'))
-    assert payload == {'foo': ['first', 'second'], 'bar': 'example'}
+    assert payload == {'foo': ['first', 'second'], 'bar': 'example', 'random/field': 'value'}
     assert http_requests.count() == 1
 
     http_requests.empty()

wcs/wscalls.py

@@ -17,6 +17,7 @@
 import collections
 import hashlib
 import json
+import re
 import urllib.parse
 import xml.etree.ElementTree as ET
 
@@ -72,10 +73,11 @@ def unflatten_keys(d):
             if misc.is_ascii_digit(x):
                 return int(x)
             elif isinstance(x, str):
+                # allow / char escaping
                 return x.replace('//', '/')
             return x
 
-        return [map_key(x) for x in key.split('/')]
+        return [map_key(x) for x in re.split(r'(?<!/)/(?!/)', key)]
 
     keys = [(split_key(key), key) for key in d]
     try: