pr分支过长，显示时应固定宽度

src/forge/Merge/CreateMerge.js

@@ -367,7 +367,7 @@ class CreateMerge extends Component {
                     value={pull}
                     onSelect={(e) => this.selectBrach('pull', e)}
                     showSearch
-                    className="merge-flex1 flex1"
+                    className="merge-flex1 flex1 matchwidth"
                     dropdownMatchSelectWidth={false}
                   >
                     {this.renderBrances(pullBranches)}
@@ -394,7 +394,7 @@ class CreateMerge extends Component {
                       value={merge}
                       onSelect={(e) => this.selectBrach('merge', e)}
                       showSearch
-                      className="merge-flex1 flex1"
+                      className="merge-flex1 flex1 matchwidth"
                       dropdownMatchSelectWidth={false}
                     >
                       {this.renderBrances(mergeBranches)}

src/forge/Merge/merge.css

@@ -213,4 +213,8 @@ form .ant-cascader-picker, form .ant-select {
 .mergeRequest .folders{
     /* width: 72rem; */
     width: 100%;
-  }
+  }
+
+ .matchwidth .ant-select-selection__rendered{
+   max-width: 200px;
+ }