never trust the client

extension/ui/pages/options.html

@@ -28,7 +28,7 @@
 			<h4>Page content</h4>
 			<div class="option">
 				<label for="maxResourceSizeInput">maximum size of embedded resources (Mb)</label>
-				<input type="number" id="maxResourceSizeInput">
+				<input type="number" id="maxResourceSizeInput" min="0">
 			</div>
 			<div class="option">
 				<label for="lazyLoadImagesInput">load lazy loaded images</label>