I noticed machines with a description that contains one apostrophe (') were
neither displayed in the Windows network neighbourhood nor smbclient -L //PDC
listed them anymore since I updated to samba 3.  

I analyzed the problem.

It traced down to the following change from samba 2.2.x to 3.0 in
lib/util_str.c:next_token():

-               if (*s == '\"') {
+               if (*s == '\"' || *s == '\'') {
                        quoted = !quoted;
                } else {
                        len++;
                        *pbuf++ = *s;
                }

This function is used in lanman.c:get_server_info(), to
tokenize lines from browse.dat.  My browse.dat contained:

"KANGAROO"                40011003 "Peter's Workstation"         "MAIN"

This caused the line to be tokenized incorrectly into <KANGAROO> <40011003> 
<Peters> <Workstation         MAIN> instead of <KANGAROO> <40011003> <Peter's
Workstation> <MAIN>.  This caused !strequal(domain, s->domain) (ie
!strequal("MAIN", "Workstation         MAIN")) in lanman.c:get_server_info() to
be true, so it set ok = False, which finally caused the entry to be omitted from
the server list.

This bug might cause other severe problems in code that uses next_token().

Suggestion:

a) investigate if ' is really required as a quote char.
b) if yes, make sure ' is only balanced by another ', not ", and " only
by ", not ', for example (code has not been tested):

-       BOOL quoted;	
+       int qchar = 0;

        ...


-               if (*s == '\"' || *s == '\'') {
-                       quoted = !quoted;
+               if ((*s == '\"' || *s == '\'') && (!qchar || qchar == *s)) {
+                       qchar = !qchar ? *s : 0;
                } else {
                        len++;
                        *pbuf++ = *s;
                }

c) if no, revert back to 2.2 code:

-               if (*s == '\"' || *s == '\'') {
+               if (*s == '\"') {
                        quoted = !quoted;
                } else {
                        len++;
                        *pbuf++ = *s;
                }

The workaround is, of course, to remove ' characters from machine descriptions.