Use different approval icon if current user approved

changelogs/unreleased/approval-by-me-icon.yml

+---
+title: Use different approval icon if current user approved
+merge_request: 28290
+author: Steffen Köhler
+type: changed

ee/app/views/projects/merge_requests/_approvals_count.html.haml

 - if merge_request.approval_needed?
-  %li.d-none.d-sm-inline-block.has-tooltip{ title: _('Approvals'), class: ('text-success' if merge_request.approved?) }
-    = sprite_icon('approval', size: 16, css_class: 'align-middle')
+  - approval_tooltip = merge_request.has_approved?(current_user) ? _("Approvals (you've approved)") : _("Approvals")
+  %li.d-none.d-sm-inline-block.has-tooltip{ title: approval_tooltip, class: ('text-success' if merge_request.approved?) }
+    = sprite_icon((merge_request.has_approved?(current_user) ? 'approval-solid' : 'approval'), size: 16, css_class: 'align-middle')
     = merge_request.approvals_given
     %span of
     = merge_request.approvals_required

ee/spec/features/merge_requests/user_views_all_merge_requests_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'User views all merge requests' do
+  let!(:merge_request) { create(:merge_request, source_project: project, target_project: project) }
+  let(:project) { create(:project, :public, approvals_before_merge: 1) }
+  let(:user) { create(:user) }
+
+  it 'shows generic approvals tooltip' do
+    visit(project_merge_requests_path(project, state: :all))
+    expect(page.all('li').any? { |item| item["title"] == "Approvals"}).to be true
+  end
+
+  it 'shows custom tooltip after user has approved' do
+    project.add_developer(user)
+    sign_in(user)
+    merge_request.approvals.create(user: user)
+    visit(project_merge_requests_path(project, state: :all))
+    expect(page.all('li').any? { |item| item["title"] == "Approvals (you've approved)"}).to be true
+  end
+end

locale/gitlab.pot

@@ -2266,6 +2266,9 @@ msgstr ""
 msgid "Approvals"
 msgstr ""
 
+msgid "Approvals (you've approved)"
+msgstr ""
+
 msgid "Approve"
 msgstr ""