potential bug in ddd/hostname.C

[Neil Horman]

Hello-
	I think I've found a bug in hostname.C.  I've included the patch that I used to 
fix the problem.  I'm afraid I don't have the .log file handy to submit to you 
to, sorry.  Anywho, in version 3.3 (and probably 3.3.1) of ddd, in the hostname 
file, there is a call to gethostbyname, the return data of which is interrogated 
for the systems hostname and aliases.  On line 165 the h_aliases array is 
parsed, starting at entry zero.  Accroding to the gethostbyname man page, the 
h_aliases value points to a null terminated list of aliases for the supplied 
host. It appears that if there are no aliases for a given host (such as in our 
environment here), this pointer is simply NULL.  the aforementiond array parsing 
on 165 resutls in a segfault in this case.  The included patch fixes that.  If 
you have any questions, or need information regarding our environment, please 
don't hesitate to write.  Thanks a bunch!

Regards,
Neil Horman

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*Neil Horman
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--- hostname.C  Mon Dec 11 07:21:48 2000
+++ /home/nhorman/hostname.C    Fri Jun 21 08:43:33 2002
@@ -160,9 +160,12 @@
            most_qualified_host = (char *)h->h_name;
 
        // Try aliases
-       for (int i = 0; h->h_aliases[i] != 0; i++)
-           if (dots(h->h_aliases[i]) > dots(most_qualified_host))
-               most_qualified_host = h->h_aliases[i];
+        if(h->aliases)
+        { 
+           for (int i = 0; h->h_aliases[i] != 0; i++)
+               if (dots(h->h_aliases[i]) > dots(most_qualified_host))
+                   most_qualified_host = h->h_aliases[i];
+        }
 
        if (dots(most_qualified_host) == 0)
        {