Bug#31691: apt ftp bug fix

[nascheme@acs.ucalgary.ca]

Here is my humble patch...

--- ftplib.cc.dist	Thu Jul 30 23:57:02 1998
+++ ftplib.cc	Mon Jan 11 00:51:50 1999
@@ -405,7 +405,11 @@
     sin.sin_family = AF_INET;
     lhost = strdup(host);
     pnum = strchr(lhost,':');
-    if (pnum == NULL)
+    if (pnum != NULL)
+    {
+	*pnum = '\0';
+    }
+    if (pnum == NULL || pnum[1] == '\0')
     {
 #if defined(VMS)
     	sin.sin_port = htons(21);
@@ -420,12 +424,16 @@
     }
     else
     {
-	*pnum++ = '\0';
+	pnum++;
 	if (isdigit(*pnum))
 	    sin.sin_port = htons(atoi(pnum));
 	else
 	{
-	    pse = getservbyname(pnum,"tcp");
+	    if ((pse = getservbyname(pnum,"tcp")) == NULL)
+	    {
+		if(ftplib_debug > 1) perror("getservbyname");
+		return 0;
+	    }
 	    sin.sin_port = pse->s_port;
 	}
     }