ncplane_at_cursor_cell: rewrite with ncplane_at_yx_cell()

include/notcurses/notcurses.h

@@ -1336,16 +1336,7 @@ API char* ncplane_at_cursor(struct ncplane* n, uint16_t* stylemask, uint64_t* ch
 
 // Retrieve the current contents of the cell under the cursor into 'c'. This
 // cell is invalidated if the associated plane is destroyed.
-static inline int
-ncplane_at_cursor_cell(struct ncplane* n, nccell* c){
-  char* egc = ncplane_at_cursor(n, &c->stylemask, &c->channels);
-  if(!egc){
-    return -1;
-  }
-  int r = cell_load(n, c, egc);
-  free(egc);
-  return r;
-}
+API int ncplane_at_cursor_cell(struct ncplane* n, nccell* c);
 
 // Retrieve the current contents of the specified cell. The EGC is returned, or
 // NULL on error. This EGC must be free()d by the caller. The stylemask and

src/lib/notcurses.c

@@ -219,25 +219,30 @@ cursor_invalid_p(const ncplane* n){
 }
 
 char* ncplane_at_cursor(ncplane* n, uint16_t* stylemask, uint64_t* channels){
-  if(cursor_invalid_p(n)){
-    return NULL;
-  }
-  return cell_extract(n, &n->fb[nfbcellidx(n, n->y, n->x)], stylemask, channels);
+  return ncplane_at_yx(n, n->y, n->x, stylemask, channels);
 }
 
 char* ncplane_at_yx(const ncplane* n, int y, int x, uint16_t* stylemask, uint64_t* channels){
-  char* ret = NULL;
   if(y < n->leny && x < n->lenx){
     if(y >= 0 && x >= 0){
-      ret = cell_extract(n, &n->fb[nfbcellidx(n, y, x)], stylemask, channels);
+      return cell_extract(n, &n->fb[nfbcellidx(n, y, x)], stylemask, channels);
     }
   }
-  return ret;
+  return NULL;
 }
 
-int ncplane_at_yx_cell(struct ncplane* n, int y, int x, nccell* c){
-  nccell* targ = ncplane_cell_ref_yx(n, y, x);
-  return cell_duplicate(n, c, targ);
+int ncplane_at_cursor_cell(ncplane* n, nccell* c){
+  return ncplane_at_yx_cell(n, n->y, n->x, c);
+}
+
+int ncplane_at_yx_cell(ncplane* n, int y, int x, nccell* c){
+  if(y < n->leny && x < n->lenx){
+    if(y >= 0 && x >= 0){
+      nccell* targ = ncplane_cell_ref_yx(n, y, x);
+      return cell_duplicate(n, c, targ);
+    }
+  }
+  return -1;
 }
 
 void ncplane_dim_yx(const ncplane* n, int* rows, int* cols){