fix dynamic regex definitions for schema validation with colander>=2 …

…that modifies URL_REGEX pattern (relates to Pylons/colander#352)

CHANGES.rst

@@ -16,7 +16,8 @@ Changes:
 
 Fixes:
 ------
-- No change.
+- Fix dynamic regex definitions for schema validation with ``colander>=2`` that modifies ``URL_REGEX`` pattern
+  (relates to `Pylons/colander#352 <https://github.com/Pylons/colander/pull/352>`_).
 
 .. _changes_4.28.0:
 

weaver/wps_restapi/colander_extras.py

@@ -354,7 +354,9 @@ def __init__(self, schemes=None, path_pattern=None, msg=None, flags=re.IGNORECAS
         if path_pattern:
             if isinstance(path_pattern, RegexPattern):
                 path_pattern = path_pattern.pattern
-            regex = f"{regex[:-1] + path_pattern}$"
+            # depending colander version: $ end-of-line, \Z end-of-string (before \n if any), or \z end-of-string (\0)
+            index = -2 if regex.lower().endswith(r"\z") else -1 if regex.endswith("$") else 0
+            regex = rf"{regex[:index] + path_pattern}\Z"
         super(SchemeURL, self).__init__(regex, msg=msg, flags=flags)