failure. The function +json_error_string()+ maps error codes to
explanatory messages.
-When an error is returned and the end pointer argument
-is non-null, it is filled with the value of the buffer
-pointer at the time the error was thrown.
+When an error is returned and the end pointer (third) argument is
+non-null, it is filled with the value of the buffer pointer at the
+time the error was thrown.
+
== BUGS ==
A backslash escape of "\0000" in a string value will drop a NUL in the
string that is likely to confuse C code looking at the storage. In