From bd4eaf9f8f95939e6781fd21792feec6af044e44 Mon Sep 17 00:00:00 2001
From: Dante <duanjl.china@gmail.com>
Date: Wed, 24 Mar 2021 07:56:15 +0800
Subject: [PATCH] fix: corrected horizontal slip judgment (#8387)

---
 src/mixins/touch.js |  3 ++-
 test/event.ts       | 18 +++++++++++++++---
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/src/mixins/touch.js b/src/mixins/touch.js
index 45f9190da..2ca378138 100644
--- a/src/mixins/touch.js
+++ b/src/mixins/touch.js
@@ -28,7 +28,8 @@ export const TouchMixin = {
 
     touchMove(event) {
       const touch = event.touches[0];
-      this.deltaX = touch.clientX - this.startX;
+      // Fix: Safari back will set clientX to negative number
+      this.deltaX = touch.clientX < 0 ? 0 : touch.clientX - this.startX;
       this.deltaY = touch.clientY - this.startY;
       this.offsetX = Math.abs(this.deltaX);
       this.offsetY = Math.abs(this.deltaY);
diff --git a/test/event.ts b/test/event.ts
index 458523f9a..1fba3c324 100644
--- a/test/event.ts
+++ b/test/event.ts
@@ -48,10 +48,22 @@ export function trigger(
 // simulate drag gesture
 export function triggerDrag(
   el: Wrapper<Vue> | HTMLElement,
-  x = 0,
-  y = 0
+  relativeX = 0,
+  relativeY = 0
 ): void {
-  trigger(el, 'touchstart', 0, 0);
+  let x = relativeX;
+  let y = relativeY;
+  let startX = 0;
+  let startY = 0;
+  if (relativeX < 0) {
+    startX = Math.abs(relativeX);
+    x = 0;
+  }
+  if (relativeY < 0) {
+    startY = Math.abs(relativeY);
+    y = 0;
+  }
+  trigger(el, 'touchstart', startX, startY);
   trigger(el, 'touchmove', x / 4, y / 4);
   trigger(el, 'touchmove', x / 3, y / 3);
   trigger(el, 'touchmove', x / 2, y / 2);