Fixes #10370: Improved and deprecated dropdown menu alignment options

* Removes an old pair of selectors that didn’t properly target the
right-aligned navbar alignment of dropdown menus.
* Deprecates the `.pull-right` alignment in favor of a more specific
and unique class name.
* Adds `.dropdown-menu-right` as the new alignment class. This is then
mixin-ed into the `.navbar-right.navbar-nav` dropdown menus for
auto-alignment.
* To override that auto-alignment, use `.dropdown-menu-left` as needed.

1 files changed, 12 insertions, 5 deletions

diff --git a/dist/css/bootstrap.css b/dist/css/bootstrap.css
index 45f868ca56..ef2293133d 100644
--- a/dist/css/bootstrap.css
+++ b/dist/css/bootstrap.css
@@ -2965,6 +2965,14 @@ input[type="button"].btn-block {
 .open > a {
   outline: 0;
 }
+.dropdown-menu-right {
+  right: 0;
+  left: auto;
+}
+.dropdown-menu-left {
+  right: auto;
+  left: 0;
+}
 .dropdown-header {
   display: block;
   padding: 3px 20px;
@@ -3001,6 +3009,10 @@ input[type="button"].btn-block {
     right: 0;
     left: auto;
   }
+  .navbar-right .dropdown-menu-left {
+    right: auto;
+    left: 0;
+  }
 }
 .btn-group,
 .btn-group-vertical {
@@ -3776,11 +3788,6 @@ textarea.input-group-sm > .input-group-btn > .btn {
   border-bottom-right-radius: 0;
   border-bottom-left-radius: 0;
 }
-.navbar-nav.pull-right > li > .dropdown-menu,
-.navbar-nav > li > .dropdown-menu.pull-right {
-  right: 0;
-  left: auto;
-}
 .navbar-btn {
   margin-top: 8px;
   margin-bottom: 8px;