Beagle SCM

JS-007 MED: main() script load — wrong file, ftell -1 → malloc(0) OOB, ignored fread

main() opens argv[1] instead of the parsed script_file, trusts ftell unchecked, and ignores the fread count. Method: Issues.

Input

Context

• main.cpp:212-222 opens argv[1] instead of the parsed script_file → wrong

  file with --eval X file.js.

• ftell can return -1 → malloc(0) then script[-1] OOB.
• The fread return is ignored → a short read leaves uninitialised script bytes

  before the NUL.

• WITH_JS-gated WIP.

Goals

• The parsed script_file is loaded; a failed ftell / short fread is detected,

  not silently mis-handled.

Constraints

• Use script_file; check len >= 0; check the fread count.

WIP

Design decisions

• (open) Replace argv[1] with script_file; guard ftell and fread.

TODOs

• Repro-first: --eval X file.js runs file.js; an empty/unreadable file does

  not crash.

• Apply the three guards.

Blockers

• None.

Outcome

• LANDED 24f890ed (2026-06-16): main() opens the parsed script_file

  (not argv[1]), errors on ftell < 0, checks malloc, and NUL-terminates at the actual fread count; new JABCscriptFile ctest (test/run-007.sh) is red-before/green-after on the wrong-file open.