Path: utzoo!attcan!uunet!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!kate.mita.keio.ac.jp!kaz
From: kaz@kate.mita.keio.ac.jp (Kazuhiro Kitagawa)
Newsgroups: comp.soft-sys.andrew
Subject: difference of strlen
Message-ID: <AZCPBvS56zsL8jC0NS@kate.mita>
Date: 16 Oct 89 10:54:51 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 42

The   bush program  runs RT-PC correctly, but
it does not run on Sun 3 sometime in paticular case.
 On Sun 3, it dumps core  with Segment violation when
searching the files with unknown uid.

---------bush.c ---------------
static void
AllocNameSpace( target, source )
    char	    **target, *source;
{
    if(!target) return;
    if(*target) free(*target);
    if(*target = malloc(strlen(source)+1)) 
	strcpy(*target,source);
}
------------------------------------------

The follwoing code includes  bug.
On RT-PC, strlen()  dose not dumps core, if source is NULL,
On Sun 3, strlen dumps core. 
Sometime  AllocNameSpace   is called as second arguement being NULL.

Because of, on RT-PC users can read address 0 and it value is NULL,
but, on Sun 3 we can not read address 0.



This  program(bush) should include   the follwoing code at first line.
static void
AllocNameSpace( target, source )
    char	    **target, *source;
{
    if(!source)return
    if(!target) return;
    if(*target) free(*target);
    if(*target = malloc(strlen(source)+1)) 
	strcpy(*target,source);
}


    Kaz. Kitagawa Phd. Candidate
    KEIO Univ. Dept of math.