allglyph: don't print UTF-16 surrogate characters #740

src/demo/all.c

@@ -24,15 +24,19 @@ allglyphs(struct notcurses* nc, struct ncplane* column, int legendy){
     for(long int c = 0 ; c < 0x10000l ; ++c){
       const char32_t wc = *plane * 0x10000l + c;
       wchar_t w[2] = { wc, L'\0', };
+      // surrogates are meaningful only for UTF-16
+      if(wc >= 0xd800 && wc <= 0xdfff){
+        continue;
+      }
       if(wcwidth(w[0]) >= 1){
         int x;
         if(ncplane_putwegc(column, w, NULL) < 0){
           return -1;
         }
-        ncplane_cursor_yx(column, NULL, &x);
         if(ncplane_printf_aligned(std, legendy, NCALIGN_CENTER, "0x%06x", wc) < 0){
           return -1;
         }
+        ncplane_cursor_yx(column, NULL, &x);
         if(x >= dimx){
           DEMO_RENDER(nc);
           ncplane_set_fg_rgb(column,
@@ -64,6 +68,8 @@ int allglyphs_demo(struct notcurses* nc){
   if(ncplane_highgradient(n, tl, tr, bl, br, dimy - 1, dimx - 1) < 0){
     return -1;
   }
+  ncplane_set_fg(n, 0xf0f0a0);
+  ncplane_set_bg(n, 0);
   int width = 40;
   if(width > dimx - 8){
     if((width = dimx - 8) <= 0){