From 0fe736cd3fbd10d0bb4f510ca897a87774983559 Mon Sep 17 00:00:00 2001
From: Mark Tolmacs <mark@lazycat.hu>
Date: Wed, 19 Mar 2025 13:49:28 +0100
Subject: [PATCH] Fix incorrect elbow arrow geometry

---
 packages/excalidraw/element/binding.ts        | 21 +++++++-----
 packages/excalidraw/element/elbowArrow.ts     | 13 ++++----
 .../excalidraw/element/linearElementEditor.ts | 33 ++++++++++++++++---
 3 files changed, 49 insertions(+), 18 deletions(-)

diff --git a/packages/excalidraw/element/binding.ts b/packages/excalidraw/element/binding.ts
index 38b7d8636..6799d1a6b 100644
--- a/packages/excalidraw/element/binding.ts
+++ b/packages/excalidraw/element/binding.ts
@@ -839,14 +839,19 @@ export const updateBoundElements = (
       }> => update !== null,
     );
 
-    LinearElementEditor.movePoints(element, updates, {
-      ...(changedElement.id === element.startBinding?.elementId
-        ? { startBinding: bindings.startBinding }
-        : {}),
-      ...(changedElement.id === element.endBinding?.elementId
-        ? { endBinding: bindings.endBinding }
-        : {}),
-    });
+    LinearElementEditor.movePoints(
+      element,
+      updates,
+      {
+        ...(changedElement.id === element.startBinding?.elementId
+          ? { startBinding: bindings.startBinding }
+          : {}),
+        ...(changedElement.id === element.endBinding?.elementId
+          ? { endBinding: bindings.endBinding }
+          : {}),
+      },
+      elementsMap as NonDeletedSceneElementsMap,
+    );
 
     const boundText = getBoundTextElement(element, elementsMap);
     if (boundText && !boundText.isDeleted) {
diff --git a/packages/excalidraw/element/elbowArrow.ts b/packages/excalidraw/element/elbowArrow.ts
index 533d2c228..a8c22abcc 100644
--- a/packages/excalidraw/element/elbowArrow.ts
+++ b/packages/excalidraw/element/elbowArrow.ts
@@ -984,7 +984,7 @@ export const updateElbowArrowPoints = (
       : updates.points.slice()
     : arrow.points.slice();
 
-  // 0. During all element replacement in the scene, we just need to renormalize
+  // During all element replacement in the scene, we just need to renormalize
   // the arrow
   // TODO (dwelle,mtolmacs): Remove this once Scene.getScene() is removed
   const {
@@ -1005,11 +1005,12 @@ export const updateElbowArrowPoints = (
     getBindableElementForId(startBinding.elementId, elementsMap);
   const endElement =
     endBinding && getBindableElementForId(endBinding.elementId, elementsMap);
+  const areUpdatedPointsValid = validateElbowPoints(updatedPoints);
 
   if (
-    (startBinding && !startElement) ||
-    (endBinding && !endElement) ||
-    (elementsMap.size === 0 && validateElbowPoints(updatedPoints)) ||
+    (startBinding && !startElement && areUpdatedPointsValid) ||
+    (endBinding && !endElement && areUpdatedPointsValid) ||
+    (elementsMap.size === 0 && areUpdatedPointsValid) ||
     (Object.keys(restOfTheUpdates).length === 0 &&
       (startElement?.id !== startBinding?.elementId ||
         endElement?.id !== endBinding?.elementId))
@@ -1050,7 +1051,7 @@ export const updateElbowArrowPoints = (
   // 0. During all element replacement in the scene, we just need to renormalize
   // the arrow
   // TODO (dwelle,mtolmacs): Remove this once Scene.getScene() is removed
-  if (elementsMap.size === 0 && validateElbowPoints(updatedPoints)) {
+  if (elementsMap.size === 0 && areUpdatedPointsValid) {
     return normalizeArrowElementUpdate(
       updatedPoints.map((p) =>
         pointFrom<GlobalPoint>(arrow.x + p[0], arrow.y + p[1]),
@@ -1083,7 +1084,7 @@ export const updateElbowArrowPoints = (
         arrow.points[i] ?? pointFrom<LocalPoint>(Infinity, Infinity),
       ),
     ) &&
-    validateElbowPoints(updatedPoints)
+    areUpdatedPointsValid
   ) {
     return {};
   }
diff --git a/packages/excalidraw/element/linearElementEditor.ts b/packages/excalidraw/element/linearElementEditor.ts
index 5368ab3d0..7db35801f 100644
--- a/packages/excalidraw/element/linearElementEditor.ts
+++ b/packages/excalidraw/element/linearElementEditor.ts
@@ -25,11 +25,16 @@ import {
 import { getGridPoint } from "../snapping";
 import { invariant, tupleToCoors } from "../utils";
 
+import Scene from "../scene/Scene";
+
 import {
   bindOrUnbindLinearElement,
   getHoveredElementForBinding,
   isBindingEnabled,
 } from "./binding";
+
+import { updateElbowArrowPoints } from "./elbowArrow";
+
 import { getElementPointsCoords, getMinMaxXYFromCurvePathOps } from "./bounds";
 import { headingIsHorizontal, vectorToHeading } from "./heading";
 import { mutateElement } from "./mutateElement";
@@ -57,7 +62,6 @@ import type {
   FixedSegment,
   ExcalidrawElbowArrowElement,
 } from "./types";
-import type Scene from "../scene/Scene";
 import type { Store } from "../store";
 import type {
   AppState,
@@ -67,6 +71,7 @@ import type {
   NullableGridSize,
   Zoom,
 } from "../types";
+
 import type { Mutable } from "../utility-types";
 
 const editorMidPointsCache: {
@@ -1274,6 +1279,7 @@ export class LinearElementEditor {
       startBinding?: PointBinding | null;
       endBinding?: PointBinding | null;
     },
+    sceneElementsMap?: NonDeletedSceneElementsMap,
   ) {
     const { points } = element;
 
@@ -1317,6 +1323,7 @@ export class LinearElementEditor {
             dragging || targetPoint.isDragging === true,
           false,
         ),
+        sceneElementsMap,
       },
     );
   }
@@ -1430,6 +1437,7 @@ export class LinearElementEditor {
     options?: {
       isDragging?: boolean;
       zoom?: AppState["zoom"];
+      sceneElementsMap?: NonDeletedSceneElementsMap;
     },
   ) {
     if (isElbowArrow(element)) {
@@ -1455,9 +1463,26 @@ export class LinearElementEditor {
 
       updates.points = Array.from(nextPoints);
 
-      mutateElement(element, updates, true, {
-        isDragging: options?.isDragging,
-      });
+      if (!options?.sceneElementsMap || Scene.getScene(element)) {
+        mutateElement(element, updates, true, {
+          isDragging: options?.isDragging,
+        });
+      } else {
+        // The element is not in the scene, so we need to use the provided
+        // scene map.
+        Object.assign(element, {
+          ...updates,
+          angle: 0 as Radians,
+          ...updateElbowArrowPoints(
+            element,
+            options.sceneElementsMap,
+            updates,
+            {
+              isDragging: options?.isDragging,
+            },
+          ),
+        });
+      }
     } else {
       const nextCoords = getElementPointsCoords(element, nextPoints);
       const prevCoords = getElementPointsCoords(element, element.points);