fix: 2182 - Heap OOB Read in switch_to_next_file()

[carbonFibreCode]

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---

fixes #2182

I moved the empty string filter before allocating the C array. Now, string_to_c_chars() only receives the exact number of valid paths, ensuring the memory allocation size perfectly matches the num_input_files limit given to the C codebase.

[cfsmp3]

Fix looks correct, but the format_rust CI check is failing. Please run cargo fmt on your changes.

[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 90128d8...:

Report Name	Tests Passed
Broken	10/13
CEA-708	2/14
DVB	4/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	79/86
Teletext	20/21
WTV	13/13
XDS	34/34

Your PR breaks these cases:

• ccextractor --out=srt --latin1 --autoprogram 73d9313d64...
• ccextractor --out=ttxt --latin1 001dd8cdf7...
• ccextractor --out=srt --latin1 4d4e938ef6...
• ccextractor --service 1 --out=txt --no-bom --no-rollup ea83ff7bcb...
• ccextractor --service 1 --out=txt f17524b53f...
• ccextractor --service 1 --out=txt 80848c45f8...
• ccextractor --service 1 --out=txt --no-bom --no-rollup b5d6aad89f...
• ccextractor --service 1[EUC-KR] --out=txt --no-rollup b5d6aad89f...
• ccextractor --service 1 --out=srt da904de35d...
• ccextractor --service 1 --out=sami da904de35d...
• ccextractor --service 1[EUC-KR] b5d6aad89f...
• ccextractor --service 1[EUC-KR] --no-rollup b5d6aad89f...
• ccextractor --service all da904de35d...
• ccextractor --service all[EUC-KR] b5d6aad89f...
• ccextractor --service 1,2[UTF-8],3[EUC-KR],54 --out=txt da904de35d...
• ccextractor --autoprogram --out=srt --latin1 d41b53b504...
• ccextractor --stdout --quiet --no-fontcolor 79a51f3500...
• ccextractor --stdout --quiet --no-fontcolor 767b546f96...
• ccextractor --service 1 c83f765c66...
• ccextractor --myth c83f765c66...
• ccextractor --in=raw fb79021542...
• ccextractor --mp4vidtrack 5df914ce77...
• ccextractor --startcreditsnotafter 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9...
• ccextractor --xmltv=3 --out=null 96efd279cf...
• ccextractor --datapid 2310 --autoprogram --out=srt --latin1 e639e54550...

NOTE: The following tests have been failing on the master branch as well as the PR:

• ccextractor --startcreditsforatmost 2 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed:

  Test 8730

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 --parsePAT --out=srt 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 --startcreditsforatleast 1 --startcreditstext "CCextractor Start crdit Testing" c4dd893cb9..., Last passed: Never
• ccextractor --endcreditsforatleast 3 --endcreditstext "CCextractor Ends crdit Testing" addf5e2fc9..., Last passed: Never

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 e4bcade...:

Report Name	Tests Passed
Broken	10/13
CEA-708	2/14
DVB	4/7
DVD	3/3
DVR-MS	2/2
General	27/27
Hardsubx	1/1
Hauppage	3/3
MP4	3/3
NoCC	10/10
Options	81/86
Teletext	20/21
WTV	13/13
XDS	34/34

NOTE: The following tests have been failing on the master branch as well as the PR:

• ccextractor --out=srt --latin1 --autoprogram 73d9313d64..., Last passed:

  Test 8611

• ccextractor --out=ttxt --latin1 001dd8cdf7..., Last passed:

  Test 8611

• ccextractor --out=srt --latin1 4d4e938ef6..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt --no-bom --no-rollup ea83ff7bcb..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt f17524b53f..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt 80848c45f8..., Last passed:

  Test 8611

• ccextractor --service 1 --out=txt --no-bom --no-rollup b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1[EUC-KR] --out=txt --no-rollup b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1 --out=srt da904de35d..., Last passed:

  Test 8611

• ccextractor --service 1 --out=sami da904de35d..., Last passed:

  Test 8611

• ccextractor --service 1[EUC-KR] b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1[EUC-KR] --no-rollup b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service all da904de35d..., Last passed:

  Test 8611

• ccextractor --service all[EUC-KR] b5d6aad89f..., Last passed:

  Test 8611

• ccextractor --service 1,2[UTF-8],3[EUC-KR],54 --out=txt da904de35d..., Last passed:

  Test 8611

• ccextractor --autoprogram --out=srt --latin1 d41b53b504..., Last passed:

  Test 8611

• ccextractor --stdout --quiet --no-fontcolor 79a51f3500..., Last passed:

  Test 8611

• ccextractor --stdout --quiet --no-fontcolor 767b546f96..., Last passed:

  Test 8611

• ccextractor --service 1 c83f765c66..., Last passed:

  Test 8611

• ccextractor --myth c83f765c66..., Last passed:

  Test 8611

• ccextractor --in=raw fb79021542..., Last passed:

  Test 8611

• ccextractor --mp4vidtrack 5df914ce77..., Last passed:

  Test 8611

• ccextractor --xmltv=3 --out=null 96efd279cf..., Last passed:

  Test 8611

• ccextractor --datapid 2310 --autoprogram --out=srt --latin1 e639e54550..., Last passed:

  Test 8611

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

This PR does not introduce any new test failures. However, some tests are failing on both master and this PR (see above).

Check the result page for more info.