fix(button): shrink abnormally in certain scenarios when using the circle prop (#1562)

CHANGELOG.en-US.md

@@ -5,6 +5,7 @@
 ### Fixes
 
 - Fix `n-grid` suffix NGridItem does not set right span when collapsed, closes [#1530](https://github.com/TuSimple/naive-ui/issues/1530).
+- Fix `n-button` to shrink abnormally in certain scenarios when using the `circle` prop, closes [#1557](https://github.com/TuSimple/naive-ui/issues/1557).
 
 ### Feats
 

CHANGELOG.zh-CN.md

@@ -5,6 +5,7 @@
 ### Fixes
 
 - 修复 `n-grid` 收缩时后缀 girdItem 设置的 span 不起作用，关闭 [#1530](https://github.com/TuSimple/naive-ui/issues/1530)
+- 修复 `n-button` 使用 `circle` 属性时在特定场景异常收缩的问题，关闭 [#1557](https://github.com/TuSimple/naive-ui/issues/1557)
 
 ### Feats
 

src/button/src/styles/button.cssr.ts

@@ -53,6 +53,7 @@ export default c([
     border: none;
     display: inline-flex;
     flex-wrap: nowrap;
+    flex-shrink: 0;
     align-items: center;
     justify-content: center;
     user-select: none;