ZSTD_initStaticCDict does not set level and it results in use of uninit value

[danlark1]

Describe the bug

ZSTD_initStaticCDict does not set compression level

To Reproduce

While running under msan, we found an error

==9312==WARNING: MemorySanitizer: use-of-uninitialized-value
    #0 0x7f4749a338a5 in ZSTD_compressBegin_usingCDict_internal zstd/compress/zstd_compress.c:5503:9
    #1 0x7f4749a339e3 in ZSTD_compress_usingCDict_internal zstd/compress/zstd_compress.c:5548:5
    #2 0x7f4749a339e3 in ZSTD_compress_usingCDict zstd/compress/zstd_compress.c:5574:12
    #3 0x7f474a860012 in basicUnitTests zstd/tests/fuzzer.c:2596:29
    #4 0x7f474a8505b2 in main zstd/tests/fuzzer.c:4734:18

This is the error

ZSTD_CCtxParams_init_internal(&cctxParams, &params, cdict->compressionLevel);

cdict->compressionLevel was not set during initialization

Expected behavior

No msan error

Desktop (please complete the following information):

• OS: Linux
• Compiler: clang

Additional context
Should be easy to fix

[yoniko]

Thank you for reporting @danlark1.

cdict->compressionLevel is indeed not set in all cases which should be fixed.
After experimentation I managed to reproduce by compiling with -O0, so I believe the reason we haven't caught it before is because the compiler is inlining / optimizing things away.

I'll add initialization and verify that we cover this case in CI.

[yoniko]

Fixed in #3257.
@danlark1 - please verify fix works for you.

[danlark1]

It works, thanks!