Handle out-of-range array index in nested JSON syntax

[ATOM00blue]

Summary

Using a very large array index in the nested JSON request item syntax makes HTTPie crash with an unhandled exception instead of reporting a syntax error.

$ http --offline --print=B pie.dev/post 'item[99999999999999999999999]:=1'
...
  File ".../httpie/cli/nested_json/interpret.py", line 87, in interpret
    cursor.extend([None] * (path.accessor - len(cursor) + 1))
OverflowError: cannot fit 'int' into an index-sized integer

A slightly smaller (but still huge) index hits MemoryError instead:

$ http --offline --print=B pie.dev/post 'item[1000000000000000000]:=1'
...
MemoryError

The root cause is that the index is used to eagerly pre-fill a list with index + 1 elements, which either overflows the platform index size or tries to allocate an enormous list.

Fix

Wrap the list expansion and turn OverflowError/MemoryError into a NestedJSONSyntaxError, mirroring the existing handling of negative indexes. The user now gets a clear message pointing at the offending value:

$ http --offline --print=B pie.dev/post 'item[99999999999999999999999]:=1'
HTTPie Value Error: The index is too large.
item[99999999999999999999999]
     ^^^^^^^^^^^^^^^^^^^^^^^

Valid sparse arrays (e.g. item[100]:=1) are unaffected.

Test plan

• Added two cases to test_nested_json_errors covering both the overflow and the large-allocation paths; they fail before the change and pass after.
• pytest tests/test_json.py passes (296 passed).
• flake8 httpie/ tests/ is clean on the changed files.

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

This PR prevents crashes in nested JSON parsing when users provide extremely large array indexes, replacing them with a user-friendly syntax error.

Changes:

• Catch OverflowError/MemoryError when expanding arrays for large indexes and raise NestedJSONSyntaxError instead.
• Add regression tests for very large index inputs and expected error rendering.
• Document the fix in the changelog under the unreleased section.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
tests/test_json.py	Adds regression cases asserting a clear error for out-of-range nested JSON array indexes.
httpie/cli/nested_json/interpret.py	Wraps array extension to convert OverflowError/MemoryError into NestedJSONSyntaxError.
CHANGELOG.md	Documents the crash fix and resulting improved error reporting.

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