cmake: fix parsing WOLFSSL_DEFINITIONS

[oltolm]

Description

There is a bug in the CMake code that parses WOLFSSL_DEFINITIONS at line 2336 in CMakeLists.txt. It uses

    if (DEFINED CMAKE_MATCH_4)

to check for a subgroup match. It stops working if there was a previous a previous regex match like this

string(REGEX MATCH "^(-D)?([^=]+)(=(.*))?$" outvar "-DVAR=VALUE")

which defines CMAKE_MATCH_4. The problem is that the next regex match does not undefine CMAKE_MATCH_4, it just sets it to the empty string.

To test it, insert

string(REGEX MATCH "^(-D)?([^=]+)(=(.*))?$" outvar "-DVAR=VALUE")

somewhere before the code and enable logging in lines 2340 and 2343.

[wolfSSL-Bot]

Can one of the admins verify this patch?

[dgarske]

Okay to test - note we are having some GitHub CI issues

[dgarske]

Please rebase to latest master to resolve GitHub CI issues. Contributor agreement on file. Let me know if you need help rebasing (I can do it from this side).