[MegaLinter][valid] C code: missing NULL checks after malloc/calloc, sprintf usage, and needs a clang-format pass

From the 2026-07-24 Analyze run, covering the only 2 C files in the repo: actions/instrument/job/forward.c and src/usr/share/opentelemetry_shell/agent.instrumentation.http/agent.injection.http_header.c. All classified as valid findings (bucket 1).

cppcheck: real robustness bugs (2 findings)

Missing NULL checks after allocation, each with a genuine null-pointer-dereference path if the allocation fails:

• forward.c:19 — original_command = malloc(total_length) (line 18) not checked before use at line 19
• forward.c:39,47,49 — new_argv = calloc(...) (line 37) not checked before use
• agent.injection.http_header.c:238-242 — my_key = calloc(...) (line 236) and my_value = calloc(...) (line 237) not checked before use

cpplint: mostly real, two rules worth reconsidering

Findings across both files: sprintf → snprintf (3 occurrences, genuine buffer-overflow-avoidance suggestion — the C equivalent of a real security nit), line length > 80 chars (~15 occurrences), trailing whitespace, comment spacing, if-body-on-separate-line style.

Two sub-rules are Google-C++-style-guide-specific and may not be worth keeping for this project specifically:

• legal/copyright — wants a // Copyright [year] <Owner> header in every file; this repo already has a top-level LICENSE, so per-file headers may be considered redundant
• readability/todo — wants // TODO(username): ... format

If you don't want those two, cpplint supports C_CPPLINT_ARGUMENTS: ["--filter=-legal/copyright,-readability/todo"] in .mega-linter.yml. Left as-is for now since it's a minor call either way.

clang-format: needs a pass (190 findings, both files)

Every line in both files is flagged — reads like clang-format has simply never been run on this code. clang-format -i actions/instrument/job/forward.c src/usr/share/opentelemetry_shell/agent.instrumentation.http/agent.injection.http_header.c should resolve the bulk of it in one shot.