[fix] Fix link deletion from middle button when connected to reroute nodes deletes wrong link (#4928)

Co-authored-by: github-actions <github-actions@github.com>

browser_tests/assets/reroute/single-native-reroute-default-workflow.json

@@ -0,0 +1,259 @@
+{
+  "id": "dec788c2-9829-4a5d-a1ee-d6f0a678b42a",
+  "revision": 0,
+  "last_node_id": 9,
+  "last_link_id": 9,
+  "nodes": [
+    {
+      "id": 7,
+      "type": "CLIPTextEncode",
+      "pos": [413, 389],
+      "size": [425.27801513671875, 180.6060791015625],
+      "flags": {},
+      "order": 3,
+      "mode": 0,
+      "inputs": [
+        {
+          "name": "clip",
+          "type": "CLIP",
+          "link": 5
+        }
+      ],
+      "outputs": [
+        {
+          "name": "CONDITIONING",
+          "type": "CONDITIONING",
+          "slot_index": 0,
+          "links": [6]
+        }
+      ],
+      "properties": {
+        "Node name for S&R": "CLIPTextEncode"
+      },
+      "widgets_values": ["text, watermark"]
+    },
+    {
+      "id": 6,
+      "type": "CLIPTextEncode",
+      "pos": [415, 186],
+      "size": [422.84503173828125, 164.31304931640625],
+      "flags": {},
+      "order": 2,
+      "mode": 0,
+      "inputs": [
+        {
+          "name": "clip",
+          "type": "CLIP",
+          "link": 3
+        }
+      ],
+      "outputs": [
+        {
+          "name": "CONDITIONING",
+          "type": "CONDITIONING",
+          "slot_index": 0,
+          "links": [4]
+        }
+      ],
+      "properties": {
+        "Node name for S&R": "CLIPTextEncode"
+      },
+      "widgets_values": [
+        "beautiful scenery nature glass bottle landscape, , purple galaxy bottle,"
+      ]
+    },
+    {
+      "id": 5,
+      "type": "EmptyLatentImage",
+      "pos": [473, 609],
+      "size": [315, 106],
+      "flags": {},
+      "order": 0,
+      "mode": 0,
+      "inputs": [],
+      "outputs": [
+        {
+          "name": "LATENT",
+          "type": "LATENT",
+          "slot_index": 0,
+          "links": [2]
+        }
+      ],
+      "properties": {
+        "Node name for S&R": "EmptyLatentImage"
+      },
+      "widgets_values": [512, 512, 1]
+    },
+    {
+      "id": 3,
+      "type": "KSampler",
+      "pos": [863, 186],
+      "size": [315, 262],
+      "flags": {},
+      "order": 4,
+      "mode": 0,
+      "inputs": [
+        {
+          "name": "model",
+          "type": "MODEL",
+          "link": 1
+        },
+        {
+          "name": "positive",
+          "type": "CONDITIONING",
+          "link": 4
+        },
+        {
+          "name": "negative",
+          "type": "CONDITIONING",
+          "link": 6
+        },
+        {
+          "name": "latent_image",
+          "type": "LATENT",
+          "link": 2
+        }
+      ],
+      "outputs": [
+        {
+          "name": "LATENT",
+          "type": "LATENT",
+          "slot_index": 0,
+          "links": [7]
+        }
+      ],
+      "properties": {
+        "Node name for S&R": "KSampler"
+      },
+      "widgets_values": [
+        156680208700286,
+        "randomize",
+        20,
+        8,
+        "euler",
+        "normal",
+        1
+      ]
+    },
+    {
+      "id": 8,
+      "type": "VAEDecode",
+      "pos": [1209, 188],
+      "size": [210, 46],
+      "flags": {},
+      "order": 5,
+      "mode": 0,
+      "inputs": [
+        {
+          "name": "samples",
+          "type": "LATENT",
+          "link": 7
+        },
+        {
+          "name": "vae",
+          "type": "VAE",
+          "link": 8
+        }
+      ],
+      "outputs": [
+        {
+          "name": "IMAGE",
+          "type": "IMAGE",
+          "slot_index": 0,
+          "links": [9]
+        }
+      ],
+      "properties": {
+        "Node name for S&R": "VAEDecode"
+      },
+      "widgets_values": []
+    },
+    {
+      "id": 9,
+      "type": "SaveImage",
+      "pos": [1451, 189],
+      "size": [210, 58],
+      "flags": {},
+      "order": 6,
+      "mode": 0,
+      "inputs": [
+        {
+          "name": "images",
+          "type": "IMAGE",
+          "link": 9
+        }
+      ],
+      "outputs": [],
+      "properties": {},
+      "widgets_values": ["ComfyUI"]
+    },
+    {
+      "id": 4,
+      "type": "CheckpointLoaderSimple",
+      "pos": [26, 474],
+      "size": [315, 98],
+      "flags": {},
+      "order": 1,
+      "mode": 0,
+      "inputs": [],
+      "outputs": [
+        {
+          "name": "MODEL",
+          "type": "MODEL",
+          "slot_index": 0,
+          "links": [1]
+        },
+        {
+          "name": "CLIP",
+          "type": "CLIP",
+          "slot_index": 1,
+          "links": [3, 5]
+        },
+        {
+          "name": "VAE",
+          "type": "VAE",
+          "slot_index": 2,
+          "links": [8]
+        }
+      ],
+      "properties": {
+        "Node name for S&R": "CheckpointLoaderSimple"
+      },
+      "widgets_values": ["v1-5-pruned-emaonly-fp16.safetensors"]
+    }
+  ],
+  "links": [
+    [1, 4, 0, 3, 0, "MODEL"],
+    [2, 5, 0, 3, 3, "LATENT"],
+    [3, 4, 1, 6, 0, "CLIP"],
+    [4, 6, 0, 3, 1, "CONDITIONING"],
+    [5, 4, 1, 7, 0, "CLIP"],
+    [6, 7, 0, 3, 2, "CONDITIONING"],
+    [7, 3, 0, 8, 0, "LATENT"],
+    [8, 4, 2, 8, 1, "VAE"],
+    [9, 8, 0, 9, 0, "IMAGE"]
+  ],
+  "groups": [],
+  "config": {},
+  "extra": {
+    "ds": {
+      "offset": [0, 0],
+      "scale": 1
+    },
+    "reroutes": [
+      {
+        "id": 1,
+        "pos": [372.66668701171875, 415.33331298828125],
+        "linkIds": [3]
+      }
+    ],
+    "linkExtensions": [
+      {
+        "id": 3,
+        "parentId": 1
+      }
+    ],
+    "frontendVersion": "1.26.1"
+  },
+  "version": 0.4
+}

browser_tests/tests/rerouteNode.spec.ts

@@ -100,4 +100,29 @@ test.describe('LiteGraph Native Reroute Node', () => {
       'native_reroute_context_menu.png'
     )
   })
+
+  test('Can delete link that is connected to two reroutes', async ({
+    comfyPage
+  }) => {
+    // https://github.com/Comfy-Org/ComfyUI_frontend/issues/4695
+    await comfyPage.loadWorkflow(
+      'reroute/single-native-reroute-default-workflow'
+    )
+
+    // To find the clickable midpoint button, we use the hardcoded value from the browser logs
+    // since the link is a bezier curve and not a straight line.
+    const middlePoint = { x: 359.4188232421875, y: 468.7716979980469 }
+
+    // Click the middle point of the link to open the context menu.
+    await comfyPage.page.mouse.click(middlePoint.x, middlePoint.y)
+
+    // Click the "Delete" context menu option.
+    await comfyPage.page
+      .locator('.litecontextmenu .litemenu-entry', { hasText: 'Delete' })
+      .click()
+
+    await expect(comfyPage.canvas).toHaveScreenshot(
+      'native_reroute_delete_from_midpoint_context_menu.png'
+    )
+  })
 })

src/lib/litegraph/src/LGraphCanvas.ts

@@ -6234,9 +6234,17 @@ export class LGraphCanvas
           break
         }
 
-        case 'Delete':
-          graph.removeLink(segment.id)
+        case 'Delete': {
+          // segment can be a Reroute object, in which case segment.id is the reroute id
+          const linkId =
+            segment instanceof Reroute
+              ? segment.linkIds.values().next().value
+              : segment.id
+          if (linkId !== undefined) {
+            graph.removeLink(linkId)
+          }
           break
+        }
         default:
       }
     }