Show tooltip when trying to edit file when not on branch

app/helpers/blob_helper.rb

@@ -30,26 +30,24 @@ module BlobHelper
         nil
       end
 
-    if blob_viewable?(blob)
+    return unless blob && blob_editable?(blob)
+
     text = 'Edit'
     after = options[:after] || ''
     from_mr = options[:from_merge_request_id]
     link_opts = {}
     link_opts[:from_merge_request_id] = from_mr if from_mr
     cls = 'btn btn-small'
-      if allowed_tree_edit?(project, ref)
     link_to(text,
             namespace_project_edit_blob_path(project.namespace, project,
                                              tree_join(ref, path),
                                              link_opts),
             class: cls
-               )
-      else
-        content_tag :span, text, class: cls + ' disabled'
-      end + after.html_safe
-    else
-      ''
+           ) + after.html_safe
   end
+
+  def blob_editable?(blob, project = @project, ref = @ref)
+    allowed_tree_edit?(project, ref) && !blob.lfs_pointer?
   end
 
   def leave_edit_message

app/helpers/tree_helper.rb

@@ -46,13 +46,20 @@ module TreeHelper
     File.join(*args)
   end
 
+  def on_top_of_branch?(project = @project, ref = @ref)
+    project.repository.branch_names.include?(ref)
+  end
+
   def allowed_tree_edit?(project = nil, ref = nil)
     project ||= @project
+    ref ||= @ref
+    return false unless on_top_of_branch?(project, ref)
+
     can?(current_user, :push_code, project)
   end
 
   def tree_edit_branch(project = @project, ref = @ref)
-    if allowed_tree_edit?
+    if allowed_tree_edit?(project, ref)
       if can_push_branch?(project, ref)
         ref
       else
@@ -61,10 +68,6 @@ module TreeHelper
     end
   end
 
-  def can_delete_or_replace?(blob)
-    allowed_tree_edit? && !blob.lfs_pointer?
-  end
-
   def tree_breadcrumbs(tree, max_links = 2)
     if @path.present?
       part_path = ""

app/services/files/base_service.rb

@@ -53,7 +53,7 @@ module Files
 
       unless project.empty_repo?
         unless repository.branch_names.include?(@current_branch)
-          raise_error("You can only create files if you are on top of a branch")
+          raise_error("You can only create or edit files when you are on top of a branch")
         end
 
         if @current_branch != @target_branch

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

 .btn-group.tree-btn-group
-  = edit_blob_link(@project, @ref, @path)
   = link_to 'Raw', namespace_project_raw_path(@project.namespace, @project, @id),
       class: 'btn btn-sm', target: '_blank'
   -# only show normal/blame view links for text files
@@ -12,11 +11,16 @@
           class: 'btn btn-sm' unless @blob.empty?
   = link_to 'History', namespace_project_commits_path(@project.namespace, @project, @id),
       class: 'btn btn-sm'
-  - if @ref != @commit.sha
   = link_to 'Permalink', namespace_project_blob_path(@project.namespace, @project,
       tree_join(@commit.sha, @path)), class: 'btn btn-sm'
 
-- if can_delete_or_replace?(@blob)
+- if blob_editable?(@blob)
   .btn-group{ role: "group" }
+    = edit_blob_link(@project, @ref, @path)
     %button.btn.btn-default{ 'data-target' => '#modal-upload-blob', 'data-toggle' => 'modal' } Replace
     %button.btn.btn-remove{ 'data-target' => '#modal-remove-blob', 'data-toggle' => 'modal' } Delete
+- elsif !on_top_of_branch?
+  .btn-group{ role: "group" }
+    %button.btn.btn-default.disabled.has_tooltip{title: "You can only edit files when you are on top of a branch.", data: {container: 'body'}} Edit
+    %button.btn.btn-default.disabled.has_tooltip{title: "You can only replace files when you are on top of a branch.", data: {container: 'body'}} Replace
+    %button.btn.btn-remove.disabled.has_tooltip{title: "You can only delete files when you are on top of a branch.", data: {container: 'body'}} Delete

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

@@ -6,7 +6,7 @@
 %div#tree-holder.tree-holder
   = render 'blob', blob: @blob
 
-- if can_delete_or_replace?(@blob)
+- if blob_editable?(@blob)
   = render 'projects/blob/remove'
 
   - title = "Replace #{@blob.name}"

app/views/projects/tree/_tree_header.html.haml

@@ -30,3 +30,7 @@
             = link_to '#modal-create-new-dir', { 'data-target' => '#modal-create-new-dir', 'data-toggle' => 'modal'} do
               = icon('folder fw')
               New directory
+  - elsif !on_top_of_branch?
+    %li
+      %span.btn.add-to-tree.disabled.has_tooltip{href: '#', title: "You can only add files when you are on top of a branch.", data: {container: 'body'}}
+        = icon('plus')