[CLCK0622]

Compiling a schema with const and detailed_exceptions=False raises KeyError('definition_rule') before a validator is created. Read and escape the current rule value inside the compact exception branch and pass it to both compact exception paths. This avoids resolving references or traversing annotation data in that mode, while leaving the detailed exception branch unchanged. The regression tests cover draft-06/07, both exception modes, both fast_fail values, eight constant types, matching and nonmatching inputs, executable compile_to_code output, and annotation data containing an unresolved $ref.

Reproducer (Python 3.10+):

python3 - <<'PY'
import fastjsonschema

schema = {'$schema': 'http://json-schema.org/draft-07/schema#', 'const': 1}
try:
    validate = fastjsonschema.compile(schema, detailed_exceptions=False)
except Exception as exc:
    print(type(exc).__name__ + ': ' + str(exc))
else:
    print('match:', validate(1))
    try:
        validate(2)
    except fastjsonschema.JsonSchemaValueException as exc:
        print(type(exc).__name__ + ': ' + exc.message)
PY

Before:

KeyError: 'definition_rule'

After:

match: 1
JsonSchemaValueException: data must be same as const definition: 1

Validation on Python 3.12.13: python -m pytest -m 'not benchmark' reports 4675 passed (4539 before), with the same 435 xfailed and 950 xpassed. The added regression cases fail 66 times on the original implementation. python -m pylint fastjsonschema reports the same nine existing diagnostics and 9.90/10 before and after.

AI disclosure: Codex assisted with part of the code and this description.

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