view-demo: do both a jpeg and png test

src/demo/view.c

@@ -6,24 +6,48 @@ int view_demo(struct notcurses* nc){
   int dimy, dimx;
   ncplane_dim_yx(ncp, &dimy, &dimx);
   int averr;
-  struct ncvisual* ncv = ncplane_visual_open(ncp, "../tests/dsscaw-purp.png", &averr);
+  struct ncvisual* ncv = ncplane_visual_open(ncp, "../tests/PurpleDrank.jpg", &averr);
   if(ncv == NULL){
     return -1;
   }
-  struct AVFrame* frame = ncvisual_decode(ncv, &averr);
-  if(frame == NULL){
+  struct ncvisual* ncv2 = ncplane_visual_open(ncp, "../tests/dsscaw-purp.png", &averr);
+  if(ncv2 == NULL){
     ncvisual_destroy(ncv);
     return -1;
   }
+  if(ncvisual_decode(ncv, &averr) == NULL){
+    ncvisual_destroy(ncv);
+    ncvisual_destroy(ncv2);
+    return -1;
+  }
+  if(ncvisual_decode(ncv2, &averr) == NULL){
+    ncvisual_destroy(ncv);
+    ncvisual_destroy(ncv2);
+    return -1;;
+  }
   if(ncvisual_render(ncv)){
     ncvisual_destroy(ncv);
+    ncvisual_destroy(ncv2);
     return -1;
   }
   if(notcurses_render(nc)){
     ncvisual_destroy(ncv);
+    ncvisual_destroy(ncv2);
+    return -1;
+  }
+  nanosleep(&demodelay, NULL);
+  if(ncvisual_render(ncv2)){
+    ncvisual_destroy(ncv);
+    ncvisual_destroy(ncv2);
     return -1;
   }
   ncvisual_destroy(ncv);
+  ncvisual_destroy(ncv2);
+  if(notcurses_render(nc)){
+    ncvisual_destroy(ncv);
+    ncvisual_destroy(ncv2);
+    return -1;
+  }
   nanosleep(&demodelay, NULL);
   return 0;
 }