working on undo/redo

1 files changed, 11 insertions, 9 deletions

diff --git a/src/client/views/InkStrokeProperties.ts b/src/client/views/InkStrokeProperties.ts
index 02288bbb5..58d2992e0 100644
--- a/src/client/views/InkStrokeProperties.ts
+++ b/src/client/views/InkStrokeProperties.ts
@@ -356,16 +356,18 @@ export class InkStrokeProperties {
             const oldHandlePoint = ink[handleIndex];
             const oppositeHandlePoint = ink[oppositeHandleIndex];
             const controlPoint = ink[controlIndex];
-            const newHandlePoint = { X: ink[handleIndex].X - deltaX / xScale, Y: ink[handleIndex].Y - deltaY / yScale };
             const inkCopy = ink.slice();
-            inkCopy[handleIndex] = newHandlePoint;
-            const brokenIndices = Cast(doc.brokenInkIndices, listSpec("number"));
-            const equivIndex = closed ? (controlIndex === 0 ? ink.length - 1 : controlIndex === ink.length - 1 ? 0 : -1) : -1;
-            // Rotate opposite handle if user hasn't held 'Alt' key or not first/final control (which have only 1 handle).
-            if ((!brokenIndices || (!brokenIndices?.includes(controlIndex) && !brokenIndices?.includes(equivIndex))) &&
-                (closed || (handleIndex !== 1 && handleIndex !== ink.length - 2))) {
-                const angle = this.angleChange(oldHandlePoint, newHandlePoint, controlPoint);
-                inkCopy[oppositeHandleIndex] = this.rotatePoint(oppositeHandlePoint, controlPoint, angle);
+            if (!Number.isNaN(deltaX / xScale) && !Number.isNaN(deltaY / yScale)) {
+                const newHandlePoint = { X: ink[handleIndex].X - deltaX / xScale, Y: ink[handleIndex].Y - deltaY / yScale };
+                inkCopy[handleIndex] = newHandlePoint;
+                const brokenIndices = Cast(doc.brokenInkIndices, listSpec("number"));
+                const equivIndex = closed ? (controlIndex === 0 ? ink.length - 1 : controlIndex === ink.length - 1 ? 0 : -1) : -1;
+                // Rotate opposite handle if user hasn't held 'Alt' key or not first/final control (which have only 1 handle).
+                if ((!brokenIndices || (!brokenIndices?.includes(controlIndex) && !brokenIndices?.includes(equivIndex))) &&
+                    (closed || (handleIndex !== 1 && handleIndex !== ink.length - 2))) {
+                    const angle = this.angleChange(oldHandlePoint, newHandlePoint, controlPoint);
+                    inkCopy[oppositeHandleIndex] = this.rotatePoint(oppositeHandlePoint, controlPoint, angle);
+                }
             }
             return inkCopy;
         })