Fix tab input value updating for BS4 dropdowns (#3412)

* Fix tab input value updating for BS4 dropdowns

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Co-authored-by: Barret Schloerke <[email protected]>
Co-authored-by: schloerke <[email protected]>
Co-authored-by: cpsievert <[email protected]>

Author: cpsievert

inst/www/shared/shiny.js

@@ -5958,10 +5958,11 @@ function main(): void {
     },
     getValue: function (el) {
       // prettier-ignore
+      // The BS4+ selectors may not work as is for dropdowns within dropdowns, but BS3+ dropped support for those anyway
       let anchor = isBS3()
         ? $(el).find("li:not(.dropdown).active > a")
         : $(el).find(
-          ".nav-link:not(.dropdown-toggle).active, .dropdown-menu > .dropdown-item.active"
+          ".nav-link:not(.dropdown-toggle).active, .dropdown-menu .dropdown-item.active"
         );
 
       if (anchor.length === 1) return this._getTabName(anchor);
@@ -5974,10 +5975,11 @@ function main(): void {
 
       if (value) {
         // prettier-ignore
+        // The BS4+ selectors may not work as is for dropdowns within dropdowns, but BS3+ dropped support for those anyway
         let anchors = isBS3()
           ? $(el).find("li:not(.dropdown) > a")
           : $(el).find(
-            ".nav-link:not(.dropdown-toggle), .dropdown-menu > .dropdown-item"
+            ".nav-link:not(.dropdown-toggle), .dropdown-menu .dropdown-item"
           );
 
         anchors.each(function () {