Infinite loop when loading masterfile with INCLUDE directive

When loading a zonefile, eg via ./named-compilezone -d -i full -o /dev/null x input we can enter another endless loop, when the file just contains $INCLUDE ..

The loop happens via:

#0  load_text (lctx=0x7ffff1a54300) at master.c:1083
#1  0x00007ffff78042f6 in dns_master_loadfile (master_file=<optimized out>, top=<optimized out>, origin=<optimized out>, zclass=<optimized out>, options=<optimized out>, resign=<optimized out>, callbacks=<optimized out>, 
    include_cb=<optimized out>, include_arg=<optimized out>, mctx=<optimized out>, format=<optimized out>, maxttl=<optimized out>) at master.c:2637
#2  0x00007ffff7bbd66b in zone_startload (db=0x7ffff1a18800, zone=<optimized out>, zone@entry=0x7ffff1a90000, loadtime=...) at zone.c:2641
#3  0x00007ffff7b6e362 in zone_load (zone=<optimized out>, flags=<optimized out>, locked=<optimized out>) at zone.c:2315
#4  0x000055555563cd3d in load_zone (mctx=<optimized out>, zonename=<optimized out>, filename=<optimized out>, fileformat=<optimized out>, classname=<optimized out>, maxttl=<optimized out>, zonep=<optimized out>)
    at check-tool.c:639
#5  0x000055555563afb0 in main (argc=<optimized out>, argv=<optimized out>) at named-checkzone.c:546

In load_text()there is an infinite loop:

        while (true) {
...

                        } else if (strcasecmp(DNS_AS_STR(token), "$INCLUDE") ==
                                   0)
                        {
                                COMMITALL;
...
                                GETTOKEN(lctx->lex, ISC_LEXOPT_QSTRING, &token,
                                         false); 
                                if (include_file != NULL) {
                                        isc_mem_free(mctx, include_file);
                                }

...
        next_line:;
        }

Since gettoken() returns ISC_R_NOTFILE the jump to next_line is taken and the parser ends up in an infinite loop. Catching ISC_R_NOTFILE with ISC_R_UNEXPECTED solves the issue.

#define GETTOKENERR(lexer, options, token, eol, err)                      \
        do {                                                              \
                result = gettoken(lexer, options, token, eol, callbacks); \
                switch (result) {                                         \
                case ISC_R_SUCCESS:                                       \
                        break;                                            \
                case ISC_R_UNEXPECTED:                                    \
                        goto insist_and_cleanup;                          \
                default:                                                  \
                        if (MANYERRS(lctx, result)) {                     \
                                SETRESULT(lctx, result);                  \
                                LOGIT(result);                            \
                                read_till_eol = true;                     \
                                err goto next_line;                       \
...
        } while (0)
#define GETTOKEN(lexer, options, token, eol) \
        GETTOKENERR(lexer, options, token, eol, {})