BUG: etags segfaults

[Daniel Bergström]

Hello!

 In Emacs 21.3 the etags utility seg. faults. To recreate the error you 
need to do the following steps:

   * create a file named t.erl and add the following two lines:

       -module(t).
       -define().

   * Then we execute the etags command:

       etags -o TAGS t.erl

This results in a segfault and a core dumped. The reason to the segfault 
was that in the routine erlang_attribute() it calculates the length of 
the string between ( and ) to be -1. The if statement only checks if the 
value isn't 0 to continue working with the string, while it should only 
continue if its a possitive value greather then 0.

The patch attached should correct this problem.

Cheers,
Daniel

--- emacs-21.3/lib-src/etags.c.org      Wed Mar 26 17:08:34 2003
+++ emacs-21.3/lib-src/etags.c  Wed Mar 26 17:09:43 2003
@@ -4969,7 +4969,7 @@
        {
          pos = skip_spaces (s + pos) - s;
          len = erlang_atom (s, pos);
-         if (len != 0)
+         if (len > 0)
            pfnote (savenstr (& s[pos], len), TRUE,
                    s, pos + len, lineno, linecharno);
        }