gh-135069: Fix exception message in encodings.idna module (#135071)

diff --git a/Lib/encodings/idna.py b/Lib/encodings/idna.py
index 60a8d5eb227f8221652f81914c798eef05aa1172..0c90b4c9fe18fad8e2fa6f0dbb7ae39edb0726a3 100644 (file)
--- a/Lib/encodings/idna.py
+++ b/Lib/encodings/idna.py
@@ -316,7 +316,7 @@ class IncrementalEncoder(codecs.BufferedIncrementalEncoder):
 class IncrementalDecoder(codecs.BufferedIncrementalDecoder):
     def _buffer_decode(self, input, errors, final):
         if errors != 'strict':
-            raise UnicodeError("Unsupported error handling: {errors}")
+            raise UnicodeError(f"Unsupported error handling: {errors}")
 
         if not input:
             return ("", 0)

diff --git a/Misc/NEWS.d/next/Library/2025-06-03-12-59-17.gh-issue-135069.xop30V.rst b/Misc/NEWS.d/next/Library/2025-06-03-12-59-17.gh-issue-135069.xop30V.rst
new file mode 100644 (file)
index 0000000..1affb5e
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-06-03-12-59-17.gh-issue-135069.xop30V.rst
@@ -0,0 +1,3 @@
+Fix the "Invalid error handling" exception in
+:class:`!encodings.idna.IncrementalDecoder` to correctly replace the
+'errors' parameter.