feat: added Lua5.5 support

[airween]

what

This PR adds Lua5.5 support.

Steps of implementation:

• I added Lua5.5 as possible version in build/lua.m4
• in lua.cc I had to add this version as an exception
  • note, that probably we should change this build logic in the future, eg. if a new Lua version will be released or Lua 5.1 will be unsupported
• I had to align the test/test-cases/data/match-getvars.lua which is used in one of the regression test with operator @inspectFile. Lua5.5 does not allow to change the iterator variable's value, so we need to create a local variable.

why

Lua5.5 was released and added to macOS, where we also run regression tests. Tests were failed there because Lua5.5 wasn't supported in libmodsecurity3.

references

Closes #3523

[Copilot]

Pull request overview

Adds build/runtime accommodations for Lua 5.5 so libmodsecurity3 can compile and pass regression tests on platforms that ship Lua 5.5 (e.g., macOS).

Changes:

• Extend build/lua.m4 to detect/link Lua 5.5 and define WITH_LUA_5_5.
• Update Lua engine error-handling to avoid referencing LUA_ERRGCMM when building against Lua 5.5.
• Adjust a Lua regression-test helper script to avoid mutating generic-for iterator variables (Lua 5.5 behavior).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
build/lua.m4	Adds Lua 5.5 library candidates + version detection/defines.
src/engine/lua.cc	Excludes LUA_ERRGCMM switch case when compiling with Lua 5.5.
test/test-cases/data/match-getvars.lua	Updates table-dump helper to avoid mutating loop iterator variables.

Comments suppressed due to low confidence (1)

build/lua.m4:47

• The Lua version compile tests have a logic bug for Lua 5.5: _msc_lua_ver is set to 505 by the 5.5 check, but the subsequent 5.4 AC_COMPILE_IFELSE runs unconditionally and will fail on 5.5, resetting _msc_lua_ver to empty and preventing detection. Gate the 5.4 (and subsequent) checks behind if test -z "$_msc_lua_ver"; then ... fi or rewrite these as an if/elif chain so a successful match isn’t overwritten.

        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[ #include <lua.h> ]],
            [[ #if (LUA_VERSION_NUM == 504)
               return 0;
               #else
               #error not 5.4

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud