support preview mode for mask editor.

* use original file reference instead of loaded frontend blob

bugfix:
* prevent file open dialog when save to load image

server.py

@@ -59,7 +59,7 @@ class PromptServer():
     def __init__(self, loop):
         PromptServer.instance = self
 
-        mimetypes.init(); 
+        mimetypes.init()
         mimetypes.types_map['.js'] = 'application/javascript; charset=utf-8'
         self.prompt_queue = None
         self.loop = loop
@@ -181,18 +181,43 @@ class PromptServer():
             post = await request.post()
             return image_upload(post)
 
+
         @routes.post("/upload/mask")
         async def upload_mask(request):
             post = await request.post()
 
             def image_save_function(image, post, filepath):
-                original_pil = Image.open(post.get("original_image").file).convert('RGBA')
-                mask_pil = Image.open(image.file).convert('RGBA')
+                original_ref = json.loads(post.get("original_ref"))
+                filename, output_dir = folder_paths.annotated_filepath(original_ref['filename'])
 
-                # alpha copy
-                new_alpha = mask_pil.getchannel('A')
-                original_pil.putalpha(new_alpha)
-                original_pil.save(filepath, compress_level=4)
+                # validation for security: prevent accessing arbitrary path
+                if filename[0] == '/' or '..' in filename:
+                    return web.Response(status=400)
+
+                if output_dir is None:
+                    type = original_ref.get("type", "output")
+                    output_dir = folder_paths.get_directory_by_type(type)
+
+                if output_dir is None:
+                    return web.Response(status=400)
+
+                if original_ref.get("subfolder", "") != "":
+                    full_output_dir = os.path.join(output_dir, original_ref["subfolder"])
+                    if os.path.commonpath((os.path.abspath(full_output_dir), output_dir)) != output_dir:
+                        return web.Response(status=403)
+                    output_dir = full_output_dir
+
+                file = os.path.join(output_dir, filename)
+
+                if os.path.isfile(file):
+                    with Image.open(file) as original_pil:
+                        original_pil = original_pil.convert('RGBA')
+                        mask_pil = Image.open(image.file).convert('RGBA')
+
+                        # alpha copy
+                        new_alpha = mask_pil.getchannel('A')
+                        original_pil.putalpha(new_alpha)
+                        original_pil.save(filepath, compress_level=4)
 
             return image_upload(post, image_save_function)
 
@@ -226,7 +251,6 @@ class PromptServer():
                     if 'preview' in request.rel_url.query:
                         with Image.open(file) as img:
                             preview_info = request.rel_url.query['preview'].split(';')
-
                             image_format = preview_info[0]
                             if image_format not in ['webp', 'jpeg']:
                                 image_format = 'webp'

web/extensions/core/maskeditor.js

@@ -346,7 +346,6 @@ class MaskEditorDialog extends ComfyDialog {
 
 		const rgb_url = new URL(ComfyApp.clipspace.imgs[ComfyApp.clipspace['selectedIndex']].src);
 		rgb_url.searchParams.delete('channel');
-		rgb_url.searchParams.delete('preview');
 		rgb_url.searchParams.set('channel', 'rgb');
 		orig_image.src = rgb_url;
 		this.image = orig_image;
@@ -618,10 +617,20 @@ class MaskEditorDialog extends ComfyDialog {
 		const dataURL = this.backupCanvas.toDataURL();
 		const blob = dataURLToBlob(dataURL);
 
-		const original_blob = loadedImageToBlob(this.image);
+		let original_url = new URL(this.image.src);
+
+		const original_ref = { filename: original_url.searchParams.get('filename') };
+
+		let original_subfolder = original_url.searchParams.get("subfolder");
+		if(original_subfolder)
+			original_ref.subfolder = original_subfolder;
+
+		let original_type = original_url.searchParams.get("type");
+		if(original_type)
+			original_ref.type = original_type;
 
 		formData.append('image', blob, filename);
-		formData.append('original_image', original_blob);
+		formData.append('original_ref', JSON.stringify(original_ref));
 		formData.append('type', "input");
 		formData.append('subfolder', "clipspace");
 

web/scripts/app.js

@@ -165,7 +165,7 @@ export class ComfyApp {
 				if(ComfyApp.clipspace.widgets) {
 					ComfyApp.clipspace.widgets.forEach(({ type, name, value }) => {
 						const prop = Object.values(node.widgets).find(obj => obj.type === type && obj.name === name);
-						if (prop && prop.type != 'image') {
+						if (prop && prop.type != 'button') {
 							if(typeof prop.value == "string" && value.filename) {
 								prop.value = (value.subfolder?value.subfolder+'/':'') + value.filename + (value.type?` [${value.type}]`:'');
 							}
@@ -174,10 +174,6 @@ export class ComfyApp {
 								prop.callback(value);
 							}
 						}
-						else if (prop && prop.type != 'button') {
-							prop.value = value;
-							prop.callback(value);
-						}
 					});
 				}
 			}