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From: worley@compass.com (Dale Worley)
Newsgroups: comp.lang.perl
Subject: this program dumps core
Message-ID: <1991Jan10.162134.24801@uvaarpa.Virginia.EDU>
Date: 10 Jan 91 16:21:34 GMT
Sender: mmdf@uvaarpa.Virginia.EDU (Uvaarpa Mail System)
Reply-To: worley@compass.com
Organization: The Internet
Lines: 51


   From: ruba@molbio.ethz.ch (Rudolf Baumann)

   #!/usr/bin/perl
   #
   format STDOUT =
   [etc.]
   . 

I cut out the program and ran it, and discovered a funny thing:
Mailers sometimes turn lines that consist of '.' alone into '. ', but
Perl doesn't accept trailing whitespace on the '.' that terminates a
format!  The patch below fixes this.  (Whitespace is still not allowed
*before* the '.', but that's visible.)

Also, if you want advice on finding a bug, you should include the
input that crashes the program.  In this case, the record that the
program is processing when it crashes isn't shown in the article!

*** toke.c.orig	Thu Jan 10 10:39:27 1991
--- toke.c	Thu Jan 10 10:44:59 1991
***************
*** 2356,2364 ****
  	    str_nset(tmpstr, s, eol-s);
  	    astore(stab_xarray(curcmd->c_filestab), (int)curcmd->c_line,tmpstr);
  	}
! 	if (strnEQ(s,".\n",2)) {
! 	    bufptr = s;
! 	    return froot.f_next;
  	}
  	if (*s == '#') {
  	    s = eol;
--- 2356,2368 ----
  	    str_nset(tmpstr, s, eol-s);
  	    astore(stab_xarray(curcmd->c_filestab), (int)curcmd->c_line,tmpstr);
  	}
! 	if (*s == '.') {
! 	    for (t = s+1; *t == ' ' || *t == '\t'; t++)
! 		/* empty */ ;
! 	    if (strnEQ(t,"\n",1)) {
! 		bufptr = s;
! 		return froot.f_next;
! 	    }
  	}
  	if (*s == '#') {
  	    s = eol;

Dale Worley		Compass, Inc.			worley@compass.com
--
Democracy attempts to upset nothing, but only to facilitate the
potential upset of anything.