From d4e782efab8b8d70cd92fec6cea9578c80b0a73e Mon Sep 17 00:00:00 2001
From: Martijn Cuppens <martijn.cuppens@gmail.com>
Date: Sun, 3 Feb 2019 22:07:16 +0100
Subject: [PATCH] Fix dropdown radius if `$dropdown-padding-y` is not 0
 (#28127)

---
 scss/_dropdown.scss | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/scss/_dropdown.scss b/scss/_dropdown.scss
index b82eb1655a..5e975c242b 100644
--- a/scss/_dropdown.scss
+++ b/scss/_dropdown.scss
@@ -132,12 +132,16 @@
   background-color: transparent; // For `<button>`s
   border: 0; // For `<button>`s
 
-  &:first-child {
-    @include border-top-radius($dropdown-inner-border-radius);
-  }
+  // Prevent dropdown overflow if there's no padding
+  // See https://github.com/twbs/bootstrap/pull/27703
+  @if $dropdown-padding-y == 0 {
+    &:first-child {
+      @include border-top-radius($dropdown-inner-border-radius);
+    }
 
-  &:last-child {
-    @include border-bottom-radius($dropdown-inner-border-radius);
+    &:last-child {
+      @include border-bottom-radius($dropdown-inner-border-radius);
+    }
   }
 
   @include hover-focus {