Set pattern ID type in AhoCorasickPlus::addPattern

Else there's potential for invalid memory accesses, e.g. if the memory
for pattern ID type happens to be equal to the "string" ID type and then
it accesses the associated union field which hasn't been initialized.

src/ahocorasick/AhoCorasickPlus.cpp

@@ -19,6 +19,7 @@
     along with multifast.  If not, see <http://www.gnu.org/licenses/>.
 
  * Modified by Jon Siwek: add "copy" flag to addPattern() methods
+ * Modified by Jon Siwek: fix addPattern() to set pattern ID type to "number"
 */
 
 #include "ahocorasick.h"
@@ -48,6 +49,7 @@ AhoCorasickPlus::EnumReturnStatus AhoCorasickPlus::addPattern
     patt.ptext.astring = (AC_ALPHABET_t*) pattern.data();
     patt.ptext.length = pattern.size();
     patt.id.u.number = id;
+    patt.id.type = AC_PATTID_TYPE_NUMBER;
     patt.rtext.astring = NULL;
     patt.rtext.length = 0;