9 files changed, 50 insertions, 12 deletions
diff --git a/app/assets/stylesheets/framework/dropdowns.scss b/app/assets/stylesheets/framework/dropdowns.scss
index 6397757bf88..cc74cb72795 100644
--- a/app/assets/stylesheets/framework/dropdowns.scss
+++ b/app/assets/stylesheets/framework/dropdowns.scss
@@ -622,7 +622,7 @@
 }
 
 .dropdown-content {
-  max-height: $dropdown-max-height;
+  max-height: 252px;
   overflow-y: auto;
 }
 
@@ -699,6 +699,31 @@
   border-radius: $border-radius-base;
 }
 
+.git-revision-dropdown {
+  .dropdown-content {
+    max-height: 215px;
+  }
+}
+
+.sidebar-move-issue-dropdown {
+  .dropdown-content {
+    max-height: 160px;
+  }
+}
+
+.dropdown-menu-author {
+  .dropdown-content {
+    max-height: 215px;
+  }
+}
+
+.dropdown-menu-labels {
+  .dropdown-content {
+    max-height: 128px;
+  }
+}
+
+
 .dropdown-menu-due-date {
   .dropdown-content {
     max-height: 230px;
diff --git a/app/assets/stylesheets/framework/sidebar.scss b/app/assets/stylesheets/framework/sidebar.scss
index d1d98270ad9..3dd4a613789 100644
--- a/app/assets/stylesheets/framework/sidebar.scss
+++ b/app/assets/stylesheets/framework/sidebar.scss
@@ -152,3 +152,4 @@
 .sidebar-collapsed-icon .sidebar-collapsed-value {
   font-size: 12px;
 }
+
diff --git a/app/assets/stylesheets/pages/boards.scss b/app/assets/stylesheets/pages/boards.scss
index c03d4c2eebf..318d3ddaece 100644
--- a/app/assets/stylesheets/pages/boards.scss
+++ b/app/assets/stylesheets/pages/boards.scss
@@ -31,8 +31,12 @@
 .dropdown-menu-issues-board-new {
   width: 320px;
 
+  .open & {
+    max-height: 400px;
+  }
+
   .dropdown-content {
-    max-height: 150px;
+    max-height: 162px;
   }
 }
 
diff --git a/app/assets/stylesheets/pages/events.scss b/app/assets/stylesheets/pages/events.scss
index 8871a069d5d..d9267f5cdf3 100644
--- a/app/assets/stylesheets/pages/events.scss
+++ b/app/assets/stylesheets/pages/events.scss
@@ -162,17 +162,14 @@
  * Last push widget
  */
 .event-last-push {
-  overflow: auto;
   width: 100%;
+  display: flex;
+  align-items: center;
 
   .event-last-push-text {
     @include str-truncated(100%);
-    padding: 4px 0;
     font-size: 13px;
-    float: left;
-    margin-right: -150px;
-    padding-right: 150px;
-    line-height: 20px;
+    margin-right: $gl-padding;
   }
 }
 
diff --git a/app/assets/stylesheets/pages/labels.scss b/app/assets/stylesheets/pages/labels.scss
index 0f49d15203b..b0852adb459 100644
--- a/app/assets/stylesheets/pages/labels.scss
+++ b/app/assets/stylesheets/pages/labels.scss
@@ -26,9 +26,15 @@
   }
 }
 
+.dropdown-menu-labels {
+  .dropdown-content {
+    max-height: 135px;
+  }
+}
+
 .dropdown-new-label {
   .dropdown-content {
-    max-height: 260px;
+    max-height: 136px;
   }
 }
 
diff --git a/app/assets/stylesheets/pages/search.scss b/app/assets/stylesheets/pages/search.scss
index c9363188505..dbde0720993 100644
--- a/app/assets/stylesheets/pages/search.scss
+++ b/app/assets/stylesheets/pages/search.scss
@@ -112,7 +112,7 @@ input[type="checkbox"]:hover {
     }
 
     .dropdown-content {
-      max-height: 350px;
+      max-height: 302px;
     }
   }
 
diff --git a/app/views/projects/_last_push.html.haml b/app/views/projects/_last_push.html.haml
index 6f5eb828902..6a1035d2dc7 100644
--- a/app/views/projects/_last_push.html.haml
+++ b/app/views/projects/_last_push.html.haml
@@ -13,6 +13,6 @@
 
         #{time_ago_with_tooltip(event.created_at)}
 
-      .pull-right
+      .flex-right
         = link_to new_mr_path_from_push_event(event), title: _("New merge request"), class: "btn btn-info btn-sm qa-create-merge-request" do
           #{ _('Create merge request') }
diff --git a/changelogs/unreleased/44382-ui-breakdown-for-create-merge-request.yml b/changelogs/unreleased/44382-ui-breakdown-for-create-merge-request.yml
new file mode 100644
index 00000000000..dd8c0b19d5f
--- /dev/null
+++ b/changelogs/unreleased/44382-ui-breakdown-for-create-merge-request.yml
@@ -0,0 +1,5 @@
+---
+title: Fix UI breakdown for Create merge request button
+merge_request: 17821
+author: Takuya Noguchi
+type: fixed
diff --git a/config/application.rb b/config/application.rb
index 0ff95e33a9c..13501d4bdb5 100644
--- a/config/application.rb
+++ b/config/application.rb
@@ -170,7 +170,7 @@ module Gitlab
     ENV['GIT_TERMINAL_PROMPT'] = '0'
 
     # Gitlab Read-only middleware support
-    config.middleware.insert_after ActionDispatch::Flash, 'Gitlab::Middleware::ReadOnly'
+    config.middleware.insert_after ActionDispatch::Flash, '::Gitlab::Middleware::ReadOnly'
 
     config.generators do |g|
       g.factory_bot false