texture:: undo clears pixels_to_draw; the number of pixels_to_draw displayed in the editor

mapeditor.cpp

@@ -1060,6 +1060,8 @@ namespace mapeditor {
       displaymm('d', 8, 8+fs*7, 2, vid.fsize, XLAT("d = draw"), 0);
       displaymm('l', 8, 8+fs*8, 2, vid.fsize, XLAT("l = line"), 0);
       displaymm('c', 8, 8+fs*9, 2, vid.fsize, XLAT("c = circle"), 0);
+      int s = size(texture::config.data.pixels_to_draw);
+      if(s) displaymm(0, 8, 8+fs*11, 2, vid.fsize, its(s), 0);
       }
 #endif
     else {

textures.cpp

@@ -1269,6 +1269,7 @@ void fillpixel(int x, int y, unsigned col) {
   }
 
 void texture_data::undo() {
+  texture::config.data.pixels_to_draw.clear();
   while(!undos.empty()) {
     auto p = undos.back();
     undos.pop_back();