cell_duplicate_far() fix length issue

src/lib/internal.h

@@ -385,9 +385,9 @@ static inline char*
 pool_egc_copy(const egcpool* e, const cell* c){
   char* ret;
   if(cell_simple_p(c)){
-    if( (ret = (char*)malloc(2)) ){
-      ret[0] = c->gcluster;
-      ret[1] = '\0';
+    if( (ret = (char*)malloc(sizeof(c->gcluster) + 1)) ){
+      memset(ret, 0, sizeof(c->gcluster) + 1);
+      memcpy(ret, &c->gcluster, sizeof(c->gcluster));
     }
   }else{
     ret = strdup(egcpool_extended_gcluster(e, c));
@@ -599,7 +599,7 @@ cell_duplicate_far(egcpool* tpool, cell* targ, const ncplane* splane, const cell
   targ->channels = c->channels;
   if(cell_simple_p(c)){
     targ->gcluster = c->gcluster;
-    return !!c->gcluster;
+    return strnlen((char*)&c->gcluster, sizeof(c->gcluster));
   }
   assert(splane);
   const char* egc = extended_gcluster(splane, c);

tests/wide.cpp

@@ -418,8 +418,10 @@ TEST_CASE("Wide") {
     free(egc);
     cell cl = CELL_TRIVIAL_INITIALIZER, cr = CELL_TRIVIAL_INITIALIZER;
     CHECK(3 == ncplane_at_yx_cell(n_, 1, 1, &cl));
-    REQUIRE(cell_extended_gcluster(n_, &cl));
-    CHECK(0 == strcmp("六", extended_gcluster(n_, &cl)));
+    egc = cell_strdup(n_, &cl);
+    REQUIRE(nullptr != egc);
+    CHECK(0 == strcmp("六", egc));
+    free(egc);
     CHECK(0 == ncplane_at_yx_cell(n_, 1, 2, &cr));
     REQUIRE(cell_simple_p(&cr));
     CHECK(0 == cr.gcluster);