Unicode Specials block bug

[manoe]

Libyang/yanglint cannot match characters of Unicode Specials block.

The function ly_pat_compile_xmlschema_chblocks_xmlschema2perl() responsible to translate Yang patterns containing Unicode blocks to PCRE2-compatible Perl-based regular expressions with character ranges assumes that each range literal is 19 char long. However, the Specials Unicode block is "special". It contains the disjoint U+FEFF character, and the range U+FFF0-U+FFFD. The original implementation only copies the first 19 chars of the literal, that is \x{FEFF}|\x{FFF0}. The expression is valid unfortunately, however only matches U+FEFF and U+FFF0.

The correction changes the ublock2urange two dimensional char array to a struct array, which is populated during compilation time also with the individual literal lengths to preserve performance (assuming, that the original intention for hard-coding URANGE_LEN was to avoid strlen calls).

Corresponding unit and component tests are also submitted.

[michalvasko]

Okay, thanks, seems this should be fixed but no need to add the length into the struct, a few strlen() calls do not make any difference so please adjust it.

[manoe]

CIFuzz keeps failing, however, based on the logs I cannot tell what went wrong. Can I get a little bit help with fuzzing?

[manoe]

I've rebased my branch/PR to devel, but the CIFuzz keeps failing. Apparently, the binary exits Failed to create context. Could you take a look whats wrong? I would appreciate your input.

[michalvasko]

Never mind the fuzz test, its failures are caused by recent changes of mine but please correctly rebase your branch to devel, my commits must not be part of your PR.

[manoe]

Hi, I managed (with much help) to remove your commits from my PR.