Optional padding Base64Variant still throws exception on missing padding character

[Vity01]

Consider this code (2.14.1):

ObjectMapper jsonMapper = new ObjectMapper()
               .setBase64Variant(Base64Variants.MIME_NO_LINEFEEDS.withReadPadding(Base64Variant.PaddingReadBehaviour.PADDING_ALLOWED));
final Output output = jsonMapper.readValue("""
                {
                "diff": "1sPEAASBOGM6XGFwYWNoZV9yb290X2Rldlx0bXBcX3N0YXBsZXJcNHEydHJhY3ZcYXZhc3RfZnJlZV9hbnRpdmlydXNfc2V0dXBfb25saW5lLmV4ZS8vYzpcYXBhY2hlX3Jvb3RfZGV2XHN0b3JhZ2VcY1w3XDFcYzcxZmViMTA2NDA5MTE4NzIwOGI4MGNkM2Q0NWE0YThcYXZhc3RfZnJlZV9hbnRpdmlydXNfc2V0dXBfb25saW5lLmV4ZS8FkK0pAKA2kLFgAJsXgyyBZfkKWXg6OZiYBgBYCQCASAAAgAMAAAC4AACABgEAgAoAAABYCACADgAAAJgIAIAQAAAA2AgAgBgAAAAYCWgAAIDJAAAAkHgJAwAqDwCoAAAAqBgDAIwOAAUAAQAAAPAAAIACAUABAIAEAQCABQEIAQAAOCcDAEAhADABAAB4SAMAKFgBAACgigMAqCUAAQAASLADAKgBAADwwAMAaAQAFQA"
                }
                """.stripIndent(), Output.class);
record Output(byte[] diff) {}

The diff content is missing '=' padding character, but even the used Base64Variant does not require for reading (as implemented #646), it throws MissingPadding exception.
The problem is ReaderBasedJsonParser still uses old method usesPadding() and not the new one requiresPaddingOnRead() as implemented since 2.12.

[cowtowncoder]

Thank you for reporting this, @Vity01. It does sound like a bug. I think test can be modified not to require ObjectMapper (just so it can remain here, along with fix).
I hope to tackle this in near future but if anyone else has time a PR would be much appreciated!
PR should probably go against 2.14 branch as this seems like a safe fix (could even go to 2.13 but it's not certain there will be more 2.13 patch releases).

[Vity01]

Thank you for such a quick fix. Good job!

[cowtowncoder]

Thank you for detailed report @Vity01, made it easy to fix!