Merge pull request #19735 from MatthewRayfield/v4-custom-select-disabled-styling

Add disabled styling for .custom-select

diff --cc scss/_custom-forms.scss
index 8222a65b0f6de528de7204a0bb57919730e1d059,a15aa947466d7166107881b00c386b1718e7b4d9..a5f0bdfc48935f69ea4516eae4a62310723efef6
--- 1/scss/_custom-forms.scss
--- 2/scss/_custom-forms.scss
+++ b/scss/_custom-forms.scss
@@@ -159,18 -159,14 +159,24 @@@
      border-color: $custom-select-focus-border-color;
      outline: none;
      @include box-shadow($custom-select-focus-box-shadow);
 +
 +    &::-ms-value {
 +      // For visual consistency with other platforms/browsers,
 +      // supress the default white text on blue background highlight given to
 +      // the selected option text when the (still closed) <select> receives focus
 +      // in IE and (under certain conditions) Edge.
 +      // See https://github.com/twbs/bootstrap/issues/19398.
 +      color: $input-color;
 +      background-color: $input-bg;
 +    }
    }
  
+   &:disabled {
+     color: $custom-select-disabled-color;
+     cursor: $cursor-disabled;
+     background-color: $custom-select-disabled-bg;
+   }
+ 
    // Hides the default caret in IE11
    &::-ms-expand {
      opacity: 0;

diff --cc scss/_variables.scss
Simple merge