Regex problems with directories that include two +s (tragic naming but unavoidable)

[StephenThornquist]

Bug report

Required Info:

• Operating System:
  Windows 10
• Installation type:
  Source

Steps to reproduce issue

Using rosidl_generate_interfaces in a directory that contains multiple + characters in the name results in a build failure that I can't figure out how to escape (I've tried using string(REPLACE "+" "\\+" CMAKE_SOURCE_DIR ${CMAKE_SOURCE_DIR}) and similar with no such luck. Sadly I can't change the path names -- this is inside of another piece of software that itself runs in MATLAB (I know, I know...) and that uses + in path names to packages and subpackages. There's also not an issue if there's only one +, which I also don't understand.

Rooting around online it seems like this issue is pretty common in CMake because of the regex parsing used, but install(TARGETS ..) has worked just fine; it's only the rosidl_generate_interfaces call that creates issues. I'm just not knowledgeable enough about CMake to know why or when this should fail, but it would make my life way easier if there were a nice way to just escape the + characters.