kill some signed-vs-unsigneds

src/demo/box.c

@@ -223,7 +223,7 @@ int box_demo(struct notcurses* nc, uint64_t startns){
   int y = 1, x = 0;
   ncplane_dim_yx(n, &ylen, &xlen);
   --ylen;
-  while(ylen - y >= targy && xlen - x >= targx){
+  while((int)ylen - y >= targy && (int)xlen - x >= targx){
     if(ncplane_cursor_move_yx(n, y, x)){
       return -1;
     }
@@ -255,7 +255,7 @@ int box_demo(struct notcurses* nc, uint64_t startns){
     ncplane_dim_yx(n, &ylen, &xlen);
     --ylen;
     move_ships(nc, ships, sizeof(ships) / sizeof(*ships));
-    while(ylen - y >= targy && xlen - x >= targx){
+    while((int)ylen - y >= targy && (int)xlen - x >= targx){
       if(ncplane_cursor_move_yx(n, y, x)){
         return -1;
       }

src/demo/demo.c

@@ -13,8 +13,8 @@
 #include "demo.h"
 
 // (non-)ansi terminal definition-4-life
-static const int MIN_SUPPORTED_ROWS = 24;
-static const int MIN_SUPPORTED_COLS = 76; // allow a bit of margin, sigh
+static const unsigned MIN_SUPPORTED_ROWS = 24;
+static const unsigned MIN_SUPPORTED_COLS = 76; // allow a bit of margin, sigh
 
 static char *datadir;
 static int democount;