support lcov files without TN

[Cheekie25]

Some lcov files don't have a TN: field.
The parser currently crashes in this case.
Just set current_test_name to empty at the beginning to handle this case.

The documentation
https://manpages.ubuntu.com/manpages/noble/man1/geninfo.1.html
seems to say that the testname is indeed optional:

If available, a tracefile begins with the testname which is stored in the following format:

         TN:<test name>

[RPGillespie6]

Thanks for this, do you mind adding a test case for this to run_all.sh?

You can just add a test1.no_tn.info to https://github.com/RPGillespie6/fastcov/tree/master/test/functional/expected_results

And then add a test case here:
https://github.com/RPGillespie6/fastcov/blob/master/test/functional/run_all.sh#L131

# Combine operation - Missing TN
coverage run -a ${TEST_DIR}/fastcov.py -C ${TEST_DIR}/expected_results/test1.no_tn.info --lcov -o test1.no_tn.actual.info
cmp test1.no_tn.actual.json ${TEST_DIR}/expected_results/combine5.expected.info

If not I can merge and do the test case myself

[RPGillespie6]

Looks good, thanks for adding the test.

[Cheekie25]

Looks good, thanks for adding the test.

Thank you.
Would you mind releasing a new version with those two changes ?

[RPGillespie6]

Done