fix exact str check (#469)

pallets · Oct 8, 2024 · 54bb00b · 54bb00b
2 parents b529164 + 7add29c
commit 54bb00b
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diff --git a/CHANGES.rst b/CHANGES.rst
@@ -4,6 +4,7 @@ Version 3.0.1
 Unreleased
 
 -   Address compiler warnings that became errors in GCC 14. :issue:`466`
+-   Fix compatibility with proxy objects. :issue:`467`
 
 
 Version 3.0.0

diff --git a/src/markupsafe/__init__.py b/src/markupsafe/__init__.py
@@ -34,7 +34,9 @@ def escape(s: t.Any, /) -> Markup:
     """
     # If the object is already a plain string, skip __html__ check and string
     # conversion. This is the most common use case.
-    if s.__class__ is str:
+    # Use type(s) instead of s.__class__ because a proxy object may be reporting
+    # the __class__ of the proxied value.
+    if type(s) is str:
         return Markup(_escape_inner(s))
 
     if hasattr(s, "__html__"):