Lower `CJSON_NESTING_LIMIT` from upstream default 1000 to 64 via
`SWITCH_AM_CFLAGS` / `SWITCH_AM_CXXFLAGS`. The mutually recursive
`parse_value`/`parse_array`/`parse_object` chain in cJSON consumes
~2 stack frames per nesting level, which can overflow worker
threads running on `SWITCH_THREAD_STACKSIZE` (240 KB).
SWITCH_AM_CPPFLAGS="-I${switch_srcdir}/src/include -I${switch_builddir}/src/include -I${switch_srcdir}/libs/libteletone/src"
SWITCH_AM_LDFLAGS="-lm"
+# Cap cJSON parser recursion depth. Default upstream limit (1000) can overflow
+# small thread stacks; both vendored cJSON copies (src/ and libs/esl/) honor this.
+APR_ADDTO(SWITCH_AM_CFLAGS, [-DCJSON_NESTING_LIMIT=64])
+APR_ADDTO(SWITCH_AM_CXXFLAGS, [-DCJSON_NESTING_LIMIT=64])
+
#set SOLINK variable based on compiler and host
if test "x${ax_cv_c_compiler_vendor}" = "xsun" ; then
SOLINK="-Bdynamic -dy -G"