From: HcySunYang <HcySunYang@outlook.com>
Date: Sun, 30 May 2021 00:42:13 +0000 (+0800)
Subject: fix(runtime-dom/v-model): only set selectedIndex when the value changes (#3845)
X-Git-Tag: v3.1.0-beta.7~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ecd97ee6e465ec5c841d58d96833fece4e899785;p=thirdparty%2Fvuejs%2Fcore.git

fix(runtime-dom/v-model): only set selectedIndex when the value changes (#3845)
---

diff --git a/packages/runtime-dom/src/directives/vModel.ts b/packages/runtime-dom/src/directives/vModel.ts
index a90c4466a1..f63f909b3c 100644
--- a/packages/runtime-dom/src/directives/vModel.ts
+++ b/packages/runtime-dom/src/directives/vModel.ts
@@ -224,12 +224,12 @@ function setSelected(el: HTMLSelectElement, value: any) {
       }
     } else {
       if (looseEqual(getValue(option), value)) {
-        el.selectedIndex = i
+        if (el.selectedIndex !== i) el.selectedIndex = i
         return
       }
     }
   }
-  if (!isMultiple) {
+  if (!isMultiple && el.selectedIndex !== -1) {
     el.selectedIndex = -1
   }
 }