Port hex_string_to_int from C to Rust

[Anayo-Anyafulu]

[IMPROVEMENT] Port hex_string_to_int from C to Rust

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Clean port of hex_string_to_int from C to Rust, following the same pattern as #2139.

Changes

• src/rust/lib_ccxr/src/util/hex.rs — Rust implementation reusing hex_char_to_val
• src/rust/src/libccxr_exports/util.rs — FFI export with added null check
• src/lib_ccx/utility.c — #ifndef DISABLE_RUST guard added

Note: The Rust version now accepts uppercase hex (A-F), which is an intentional improvement over the original C version that only accepted lowercase (a-f).

Testing

All 48 Rust unit tests passing locally.

[Anayo-Anyafulu]

The DVB, General, and Options test failures are pre-existing and unrelated to this change. These same categories fail on master. All build checks and format checks are passing

[cfsmp3]

Thanks for the port — the implementation is correct and tests pass. A few things to fix before merging:

1. Null check needed: ccxr_hex_string_to_int calls CStr::from_ptr() without checking if the pointer is null first. Please add a null guard.

2. Squash commits: 7 commits is too many for this change. Please squash into 1-2 meaningful commits.

3. Unrelated change: There's a blank line removal in utility.c that's not related to this PR. Please revert it.

4. Uppercase hex: The new Rust version accepts uppercase (A-F) while the C version only accepts lowercase (a-f). This is fine as an improvement, but please mention it in the PR description so it's documented as an intentional behavior change.

Once these are addressed this is ready to merge. Also note: #2139 will be closed in favor of this PR.

[Anayo-Anyafulu]

@cfsmp3

Thanks for the review! I'll address all four points — adding the null guard, squashing the commits, reverting the unrelated blank line in utility.c, and updating the PR description to document the uppercase hex behavior change. Will push the fixes shortly.

[ccextractor-bot]

CCExtractor CI platform finished running the test files on linux. Below is a summary of the test results, when compared to test for commit c3c5d9c...:

Report Name	Tests Passed
Broken	13/13
CEA-708	14/14
DVB	6/7
DVD	3/3
DVR-MS	2/2
General	25/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	80/86
Teletext	21/21
WTV	13/13
XDS	34/34

Your PR breaks these cases:

• ccextractor --autoprogram --out=srt --latin1 --quant 0 85271be4d2...
• ccextractor --autoprogram --out=ttxt --latin1 --ucla dab1c1bd65...
• ccextractor --out=srt --latin1 --autoprogram 29e5ffd34b...
• ccextractor --out=spupng c83f765c66...
• ccextractor --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9...
• ccextractor --startcreditsnotbefore 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9...
• ccextractor --startcreditsnotafter 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9...
• ccextractor --startcreditsforatleast 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9...
• ccextractor --startcreditsforatmost 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9...

It seems that not all tests were passed completely. This is an indication that the output of some files is not as expected (but might be according to you).

Check the result page for more info.

[ccextractor-bot]

CCExtractor CI platform finished running the test files on windows. Below is a summary of the test results, when compared to test for commit 8de778a...:

Report Name	Tests Passed
Broken	13/13
CEA-708	14/14
DVB	7/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	86/86
Teletext	21/21
WTV	13/13
XDS	34/34

Congratulations: Merging this PR would fix the following tests:

• ccextractor --autoprogram --out=srt --latin1 --quant 0 85271be4d2..., Last passed: Never
• ccextractor --autoprogram --out=ttxt --latin1 --ucla dab1c1bd65..., Last passed: Never
• ccextractor --out=srt --latin1 --autoprogram 29e5ffd34b..., Last passed: Never
• ccextractor --out=spupng c83f765c66..., Last passed: Never
• ccextractor --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsnotbefore 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsnotafter 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsforatleast 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --startcreditsforatmost 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never

All tests passed completely.

Check the result page for more info.