fix a bug in c code

cbits/bytestring.c

@@ -342,7 +342,7 @@ igraph_strvector_t* bsvector_to_strvector(bsvector_t* from) {
   igraph_strvector_t *str;
   size_t i;
   igraph_strvector_init(str, from->len);
-  for (i = 0; i++; i < from->len) {
+  for (i = 0; i < from->len; i++) {
     igraph_strvector_set(str, i, bytestring_to_char(from->data[i]));
   }
   return str;
@@ -352,8 +352,8 @@ bsvector_t* strvector_to_bsvector(igraph_strvector_t* from) {
   bsvector_t *str;
   size_t i;
   bsvector_init(str, from->len);
-  for (i = 0; i++; i < from->len) {
+  for (i = 0; i < from->len; i++) {
     bsvector_set(str, i, char_to_bytestring(from->data[i]));
   }
   return str;
-}
+}
\ No newline at end of file

cbits/haskell_attributes.c

@@ -466,8 +466,6 @@ int igraph_haskell_attribute_add_edges(igraph_t *graph, const igraph_vector_t *e
       }
       if (oldrec->type == IGRAPH_ATTRIBUTE_STRING) {
 				if (ne != bsvector_size(newstr)) {
-					printf("number of edges: %d\n", ne);
-					printf("number of attributes: %d\n", bsvector_size(newstr));
 					IGRAPH_ERROR("Invalid string attribute length", IGRAPH_EINVAL);
 				}
 				IGRAPH_CHECK(bsvector_append(oldstr, newstr));