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Unescaped DELETE control character U+007F fails with "unacceptable character"

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
38/100
Issue type
Bug
Clarity
Mostly clear
Activity status
Stale
Tech stack
python
Domain
api

Research direction

Start by reproducing the reported command, python -m openapi_spec_validator --schema 2.0 openapi-spec.json, with both the literal U+007F and its \u007f form. The payload names no source file or test, so trace where parsing rejects the character and whether the dependency is responsible. Done means the expected behavior is implemented and covered for both inputs, or the dependency limitation is clearly documented.

Written by the indexing model from the issue text.

Description

Note: I am not entirely sure if the source of this issue lies within the scope of this library of any of its dependencies.

Situation

My (openAPI specification) JSON file contains a string with an unescaped DELETE control character, U+007F.

"examples" : {
              "image/png" : ""  # should be U+007F (Github seems to redact this character)
            },

Output of python -m openapi_spec_validator --schema 2.0 openapi-spec.json is:

unacceptable character #x007f: special characters are not allowed
  in "<urllib response>", position 1082

If we replace the character by its encoded equivalent, like this:

"examples" : {
              "image/png" : "\u007f"
            },

the result is: OK

Expected

In my understanding, RFC 7159 (obsolete) RFC 8259 allows this specific control character to appear escaped and unescaped inside JSON strings: https://tools.ietf.org/html/rfc8259#section-7.

Therefore, I expect OK for both Inputs mentioned above.

Dominant language
Python
Stars
409
Forks
73
PR merge metrics
No merged PRs in 30d

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