Set content-disposition header for single file download in repository

app/controllers/projects/raw_controller.rb

@@ -10,7 +10,6 @@ class Projects::RawController < Projects::ApplicationController
 
   def show
     @blob = @repository.blob_at(@commit.id, @path)
-
     if @blob
       headers['X-Content-Type-Options'] = 'nosniff'
 
@@ -19,7 +18,7 @@ class Projects::RawController < Projects::ApplicationController
       if @blob.stored_externally?
         send_lfs_object
       else
-        send_git_blob @repository, @blob
+        send_git_blob @repository, @blob, params[:inline]
       end
     else
       render_404

app/helpers/blob_helper.rb

@@ -114,7 +114,7 @@ module BlobHelper
     icon("#{file_type_icon_class('file', mode, name)} fw")
   end
 
-  def blob_raw_url(only_path: false)
+  def blob_raw_url(only_path: false, inline: nil)
     if @build && @entry
       raw_project_job_artifacts_url(@project, @build, path: @entry.path, only_path: only_path)
     elsif @snippet
@@ -124,7 +124,7 @@ module BlobHelper
         raw_snippet_url(@snippet, only_path: only_path)
       end
     elsif @blob
-      project_raw_url(@project, @id, only_path: only_path)
+      project_raw_url(@project, @id, only_path: only_path, inline: inline)
     end
   end
 
@@ -226,16 +226,16 @@ module BlobHelper
 
   def open_raw_blob_button(blob)
     return if blob.empty?
-    icon = icon('file-code-o')
-    title = 'Open raw'
-    link_to icon, blob_raw_path, class: 'btn btn-sm has-tooltip', target: '_blank', rel: 'noopener noreferrer', title: title, data: { container: 'body' }
+    unless blob.raw_binary? || blob.stored_externally?
+      title = 'Open raw'
+      link_to icon('file-code-o'), blob_raw_url(:inline => true), class: 'btn btn-sm has-tooltip', target: '_blank', rel: 'noopener noreferrer', title: title, data: { container: 'body' }
+    end 
   end
 
-  def download_button(blob)
+  def download_blob_button(blob)
     return if blob.empty?
-    icon = sprite_icon('download')
     title = 'Download'
-    link_to icon, blob_raw_path, download: '', class: 'btn btn-sm has-tooltip', target: '_blank', rel: 'noopener noreferrer', title: title, data: { container: 'body' }
+    link_to sprite_icon('download'), blob_raw_url, download: @path, class: 'btn btn-sm has-tooltip', target: '_blank', rel: 'noopener noreferrer', title: title, data: { container: 'body' }
   end
 
   def blob_render_error_reason(viewer)

app/helpers/workhorse_helper.rb

@@ -2,9 +2,9 @@
 # Workhorse will also serve files when using `send_file`.
 module WorkhorseHelper
   # Send a Git blob through Workhorse
-  def send_git_blob(repository, blob)
+  def send_git_blob(repository, blob, inline)
     headers.store(*Gitlab::Workhorse.send_git_blob(repository, blob))
-    headers['Content-Disposition'] = 'inline'
+    inline ? (headers['Content-Disposition'] = 'inline') : (headers['Content-Disposition'] = 'attachment')
     headers['Content-Type'] = safe_content_type(blob)
     render plain: ""
   end

app/views/projects/blob/_header.html.haml

@@ -7,9 +7,8 @@
 
     .btn-group{ role: "group" }<
       = copy_blob_source_button(blob) unless blame
-      - if !(blob.raw_binary? || blob.stored_externally?)
-        = open_raw_blob_button(blob)
-      = download_button(blob)
+      = open_raw_blob_button(blob)
+      = download_blob_button(blob)
       = view_on_environment_button(@commit.sha, @path, @environment) if @environment
     .btn-group{ role: "group" }<
       = render_if_exists 'projects/blob/header_file_locks_link'