Improve change logic

ecs/src/world.rs

@@ -341,7 +341,7 @@ impl World {
         Ok(())
     }
 
-    pub fn commit_entity_changes(&mut self) -> Result<bool> {
+    pub fn commit_entity_changes(&mut self) -> Result<()> {
         #[cfg(debug_assertions)]
         {
             if !self.entities_to_remove.is_empty() {
@@ -361,7 +361,7 @@ impl World {
             && self.entities_to_add.is_empty()
             && self.entities_updates.is_empty()
         {
-            return Ok(false);
+            return Ok(());
         }
 
         for entity in core::mem::take(&mut self.entities_to_remove) {
@@ -409,7 +409,8 @@ impl World {
             }
         }
 
-        Ok(true)
+        self.had_entity_changes = true;
+        Ok(())
     }
 }
 
@@ -431,13 +432,16 @@ impl World {
                 self.updates.update(w)?;
             }
 
-            self.had_entity_changes = self.commit_entity_changes()?;
+            self.commit_entity_changes()?;
 
             for system in systems.iter() {
                 if !system(self)? {
                     return Ok(());
                 }
             }
+
+            // reset flag
+            self.had_entity_changes = false;
         }
     }
 }