commit a2b3f56b347c1897454eac1b5bdfe9d228302b80
Author: Jehan <jehan@girinstud.io>
Date:   Sat Jan 26 12:50:31 2019 +0100

    Boolean #define-s removed from json-c in 2017.
    
    We don't need to #undef TRUE and FALSE before including json.h as this
    redefinition has been removed in upstream json-c.
    See json-c commit 0992aac61f8b087efd7094e9ac2b84fa9c040fcd.
    
    Note that it still works even if using an older json-c since the
    original code was alreadying #undef-ing these 2 values before redefining
    them. So that was anyway useless code and this change should work both
    with old or new json-c.
    
    Note: the previous code was still working fine when building on Linux,
    but not when cross-compiling on Windows. But this is the correct fix
    anyway.
    
    (cherry picked from commit f4fd97445d3b6843af57ff8ba5f02cbdeb3942e9)

diff --git a/brushlib/mypaint-brush.c b/mypaint-brush.c
index 4759d11..7a1380c 100644
--- a/brushlib/mypaint-brush.c
+++ b/brushlib/mypaint-brush.c
@@ -35,9 +35,6 @@
 #include "rng-double.h"
 
 #ifdef HAVE_JSON_C
-// Allow the C99 define from json.h
-#undef TRUE
-#undef FALSE
 #include <json.h>
 #endif // HAVE_JSON_C