Bug in trie fixed (issue 277)

When there were both '0' and '255' subnodes in (mtrie)
the removal of the node resulted in an infinite loop.
Fixed.
Signed-off-by: Martin Sustrik <sustrik@250bpm.com>

src/mtrie.cpp

@@ -171,7 +171,7 @@ void zmq::mtrie_t::rm_helper (pipe_t *pipe_, unsigned char **buff_,
     }
 
     //  If there are multiple subnodes.
-    for (unsigned char c = 0; c != count; c++) {
+    for (unsigned short c = 0; c != count; c++) {
         (*buff_) [buffsize_] = min + c;
         if (next.table [c])
             next.table [c]->rm_helper (pipe_, buff_, buffsize_ + 1,

src/trie.cpp

@@ -219,7 +219,7 @@ void zmq::trie_t::apply_helper (
     }
 
     //  If there are multiple subnodes.
-    for (unsigned char c = 0; c != count; c++) {
+    for (unsigned short c = 0; c != count; c++) {
         (*buff_) [buffsize_] = min + c;
         if (next.table [c])
             next.table [c]->apply_helper (buff_, buffsize_ + 1, maxbuffsize_,