eigs_json_lint_allow_for is a seventh lenient JSON parse root and never clears g_json_parse_err, silently emptying the lint allow-list

[Nitjsefnie]

Describe the bug

eigs_json_lint_allow_for (src/lint.c:3228) calls eigs_json_parse_value directly without clearing g_json_parse_err first, so it is a seventh lenient JSON parse root beyond the six named in #777. When the flag is already set from an earlier parse in the same thread, the lint allow-list document decodes to an empty dict and warning suppression silently stops applying — the lint then emits warnings the allow-list was configured to suppress.

Surfaced while doing #777, whose fix routes the six entry points you named through eigs_json_parse_root. That leaves this one unmigrated; it neither caused nor fixes this.

Scope, stated up front because it matters: this is not reachable through any shipped binary. --lint handles one file per process with no JSON parse before it, and the LSP path goes through lint_collect rather than this function. It affects embedders and in-process callers that use the public C API and parse JSON before linting in the same thread. Line resolved against main @ e17f936.

To reproduce

There is no .eigs-level reproducer, for the scope reason above — the trigger requires two parses in one process, which the CLI never does. From an embedder over the public C API:

1. Lint a file with an allow-list that suppresses a warning, and confirm it reports no issues found (rc=0).
2. In the same thread, call the public eigs_json_parse_value on a malformed document, leaving g_json_parse_err set.
3. Lint the same file again with the same allow-list.

Expected behavior

Step 3 behaves identically to step 1 — the allow-list still decodes and still suppresses, because a fresh parse should not inherit error state from an unrelated earlier one.

Actual behavior

Step 3 emits warning[W001] and exits rc=1. The well-formed allow-list document decodes to an empty dict, so every entry in it is silently dropped.

Environment

• OS: Debian 13 (x86_64)
• GCC version: 14
• EigenScript version: 0.34.0 (main @ e17f936)