glr-parser hands me the wrong token

this is all from the README.txt along with sample code that demonstrates
the problem i put up on
https://github.com/GorillaSapiens/bison_glr_bug

=3D=3D=3D=3D

# bison_glr_bug

######## the bug

essentially, i believe the Bison glr-parser is handing me the wrong
yylloc and yytext under some circumstances.

in my code...

language.ypp:
805 iconst         : YYINTEGER
806                   {
807                      $$ =3D 0;
808 printf("=3D=3D=3D> %s:%d source %d:%d '%s'\n", __FILE__, __LINE__, yyli=
neno,
yylloc.first_column, yytext);
809                      assert(yytext[0] !=3D ',');
810                   }
811                ;

language.l:
 35 I_ZERO      ([0])
 36 I_NONZERO   ([1-9][0-9]*)
 37 INTEGER     {I_ZERO}|{I_NONZERO}
[...]
 92 {INTEGER}         {=E2=8F=8E
 93                      flexdebug(__LINE__, yytext, (int) YYINTEGER,
yylineno, yylloc.first_column);=E2=8F=8E
 94                      return YYINTEGER;=E2=8F=8E
 95                   }=E2=8F=8E

As you can see, the yytext for an YYINTEGER should **NEVER** contain a ','.
But yet, i'm seeing this happen (see below).

######## how to reproduce

$ git clone https://github.com/GorillaSapiens/bison_glr_bug.git
[...]

$ make
[...]

$ ./language program.txt
.l line 88, 'b', 258, source 1:1
.l line 108, '=3D', 61, source 1:3
.l line 88, 'a', 258, source 1:5
.l line 108, '<', 60, source 1:6
.l line 93, '1', 299, source 1:7
.l line 108, ',', 44, source 1:8
=3D=3D=3D> language.ypp:808 source 1:0 ','
language: language.ypp:809: YYRESULTTAG yyuserAction(yyRuleNum, int,
yyGLRStackItem*, yyGLRStack*, long int, YYSTYPE*, YYLTYPE*): Assertion
`yytext[0] !=3D ','' failed.
Aborted (core dumped)