CJSON discovery fails even if WITH_CJSON=OFF

[madhat1]

When building using cmake, and providing -DWITH_CJSON=OFF the cJson discovery process is still running and failing if I don't have cJson installed.

A simple fix in the main CMakeLists.txt will do the trick, surround the following block:

FIND_PACKAGE(cJSON)
if (CJSON_FOUND)
message(STATUS ${CJSON_FOUND})
else (CJSON_FOUND)
message(STATUS "Optional dependency cJSON not found. Some features will be disabled.")
endif(CJSON_FOUND)

with an :

if (WITH_CJSON)
...
endif()

That's all!

[ralight]

It feels like the whole point of FIND_PACKAGE(cJSON) is to deal with this... but ok, if it works I'm happy.

[madhat1]

You're right, but logically if WITH_CJSON=OFF was provided it's not correct to perform the discovery to begin with and show the 'missing cJson' warning, in this case the user explicitly wants to not use cJson.
FIND_PACKAGE(cJSON) may fail if the build environment contains a misconfigured or otherwise irrelevant cJson (for a different architecture for example).
Anyway, the fix solves all potential errors and avoids performing discovery if WITH_CJSON=OFF was provided thus adhering to the developers wishes to 'not use cJson'.