Fix #9174: pad bottom of navbar collapsed content and clear floated contents

dist/css/bootstrap.css

@@ -2869,6 +2869,30 @@ button.close {
   margin-bottom: 0;
 }
 
+.nav-collapse {
+  padding-bottom: 15px;
+}
+
+.nav-collapse:before,
+.nav-collapse:after {
+  display: table;
+  content: " ";
+}
+
+.nav-collapse:after {
+  clear: both;
+}
+
+.nav-collapse:before,
+.nav-collapse:after {
+  display: table;
+  content: " ";
+}
+
+.nav-collapse:after {
+  clear: both;
+}
+
 @media (max-width: 768px) {
   .nav-collapse-scrollable {
     max-height: 360px;
@@ -3103,6 +3127,7 @@ button.close {
   .nav-collapse.collapse {
     display: block !important;
     height: auto !important;
+    padding-bottom: 0;
     overflow: visible !important;
   }
 }

less/navbar.less

@@ -82,14 +82,18 @@
 }
 .navbar-fixed-top {
   top: 0;
-  .nav-collapse {
-  }
 }
 .navbar-fixed-bottom {
   bottom: 0;
   margin-bottom: 0; // override .navbar defaults
 }
 
+.nav-collapse {
+  // Space out collapsed contents within the mobile navbar
+  padding-bottom: @navbar-padding-vertical;
+  // Clear floated elements and prevent collapsing of padding
+  .clearfix();
+}
 
 // Scrollable navbar navigation
 //
@@ -353,6 +357,7 @@
   .nav-collapse.collapse {
     display: block !important;
     height: auto !important;
+    padding-bottom: 0; // Override default setting
     overflow: visible !important;
   }