diff --git a/test/functional/documents_controller_test.rb b/test/functional/documents_controller_test.rb
index d0e586649..8eb741249 100644
--- a/test/functional/documents_controller_test.rb
+++ b/test/functional/documents_controller_test.rb
@@ -234,6 +234,7 @@ LOREM
   end
 
   def test_destroy
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
     assert_difference 'Document.count', -1 do
       delete :destroy, :params => {
@@ -245,6 +246,7 @@ LOREM
   end
 
   def test_add_attachment
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
     assert_difference 'Attachment.count' do
       post :add_attachment, :params => {
diff --git a/test/functional/issues_controller_test.rb b/test/functional/issues_controller_test.rb
index b9ef3bb27..df3756d10 100644
--- a/test/functional/issues_controller_test.rb
+++ b/test/functional/issues_controller_test.rb
@@ -348,6 +348,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_index_grouped_by_due_date
+    set_tmp_attachments_directory
     Issue.destroy_all
     Issue.generate!(:due_date => '2018-08-10')
     Issue.generate!(:due_date => '2018-08-10')
@@ -4413,6 +4414,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_create_as_copy_with_attachments_should_also_add_new_files
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
     issue = Issue.find(3)
     count = issue.attachments.count
@@ -6672,6 +6674,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issue_with_no_time_entries_should_delete_the_issues
+    set_tmp_attachments_directory
     assert_nil TimeEntry.find_by_issue_id(2)
     @request.session[:user_id] = 2
 
@@ -6685,6 +6688,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_with_time_entries_should_show_the_reassign_form
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     with_settings :timelog_required_fields => [] do
@@ -6705,18 +6709,19 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_with_time_entries_should_not_show_the_nullify_option_when_issue_is_required_for_time_entries
+    set_tmp_attachments_directory
     with_settings :timelog_required_fields => ['issue_id'] do
       @request.session[:user_id] = 2
 
-    assert_no_difference 'Issue.count' do
-      delete :destroy, :params => {
-          :ids => [1, 3]
-        }
-    end
-    assert_response :success
+      assert_no_difference 'Issue.count' do
+        delete :destroy, :params => {
+            :ids => [1, 3]
+          }
+      end
+      assert_response :success
 
-    assert_select 'form' do
-      assert_select 'input[name=_method][value=delete]'
+      assert_select 'form' do
+        assert_select 'input[name=_method][value=delete]'
         assert_select 'input[name=todo][value=destroy]'
         assert_select 'input[name=todo][value=nullify]', 0
         assert_select 'input[name=todo][value=reassign]'
@@ -6741,6 +6746,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_and_destroy_time_entries
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     assert_difference 'Issue.count', -2 do
@@ -6757,6 +6763,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_and_assign_time_entries_to_project
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     with_settings :timelog_required_fields => [] do
@@ -6776,6 +6783,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_and_reassign_time_entries_to_another_issue
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     assert_difference 'Issue.count', -2 do
@@ -6816,6 +6824,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_and_reassign_time_entries_to_an_invalid_issue_should_fail
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     assert_no_difference 'Issue.count' do
@@ -6832,6 +6841,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_and_reassign_time_entries_to_an_issue_to_delete_should_fail
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     assert_no_difference 'Issue.count' do
@@ -6848,6 +6858,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_and_nullify_time_entries_should_fail_when_issue_is_required_for_time_entries
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     with_settings :timelog_required_fields => ['issue_id'] do
@@ -6865,6 +6876,7 @@ class IssuesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_issues_from_different_projects
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
 
     assert_difference 'Issue.count', -3 do
diff --git a/test/functional/journals_controller_test.rb b/test/functional/journals_controller_test.rb
index b003a3659..b5df9cffa 100644
--- a/test/functional/journals_controller_test.rb
+++ b/test/functional/journals_controller_test.rb
@@ -62,6 +62,7 @@ class JournalsControllerTest < Redmine::ControllerTest
   end
 
   def test_index_should_show_visible_custom_fields_only
+    set_tmp_attachments_directory
     Issue.destroy_all
     Journal.delete_all
     field_attributes = {:field_format => 'string', :is_for_all => true, :is_filter => true, :trackers => Tracker.all}
diff --git a/test/functional/messages_controller_test.rb b/test/functional/messages_controller_test.rb
index 64c70157b..ad193b119 100644
--- a/test/functional/messages_controller_test.rb
+++ b/test/functional/messages_controller_test.rb
@@ -232,6 +232,7 @@ class MessagesControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_topic
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
     assert_difference 'Message.count', -3 do
       post :destroy, :params => {
diff --git a/test/functional/projects_controller_test.rb b/test/functional/projects_controller_test.rb
index 63159ab90..cd1476a76 100644
--- a/test/functional/projects_controller_test.rb
+++ b/test/functional/projects_controller_test.rb
@@ -834,6 +834,7 @@ class ProjectsControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_without_confirmation_should_show_confirmation_with_subprojects
+    set_tmp_attachments_directory
     @request.session[:user_id] = 1 # admin
 
     assert_no_difference 'Project.count' do
@@ -849,6 +850,7 @@ class ProjectsControllerTest < Redmine::ControllerTest
   end
 
   def test_destroy_with_confirmation_should_destroy_the_project_and_subprojects
+    set_tmp_attachments_directory
     @request.session[:user_id] = 1 # admin
 
     assert_difference 'Project.count', -5 do
diff --git a/test/functional/wiki_controller_test.rb b/test/functional/wiki_controller_test.rb
index 6ee3bff51..7d36ea3f2 100644
--- a/test/functional/wiki_controller_test.rb
+++ b/test/functional/wiki_controller_test.rb
@@ -273,6 +273,7 @@ class WikiControllerTest < Redmine::ControllerTest
   end
 
   def test_create_page_with_attachments
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
     assert_difference 'WikiPage.count' do
       assert_difference 'Attachment.count' do
@@ -443,6 +444,7 @@ class WikiControllerTest < Redmine::ControllerTest
   end
 
   def test_update_page_with_attachments_only_should_not_create_content_version
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
     assert_no_difference 'WikiPage.count' do
       assert_no_difference 'WikiContent.count' do
@@ -1179,6 +1181,7 @@ class WikiControllerTest < Redmine::ControllerTest
   end
 
   def test_add_attachment
+    set_tmp_attachments_directory
     @request.session[:user_id] = 2
     assert_difference 'Attachment.count' do
       post :add_attachment, :params => {
diff --git a/test/functional/wikis_controller_test.rb b/test/functional/wikis_controller_test.rb
index 5b53aaae8..fad3d8365 100644
--- a/test/functional/wikis_controller_test.rb
+++ b/test/functional/wikis_controller_test.rb
@@ -27,6 +27,7 @@ class WikisControllerTest < Redmine::ControllerTest
   end
 
   def test_get_destroy_should_ask_confirmation
+    set_tmp_attachments_directory
     @request.session[:user_id] = 1
     assert_no_difference 'Wiki.count' do
       get :destroy, :params => {:id => 1}
@@ -35,6 +36,7 @@ class WikisControllerTest < Redmine::ControllerTest
   end
 
   def test_post_destroy_should_delete_wiki
+    set_tmp_attachments_directory
     @request.session[:user_id] = 1
     post :destroy, :params => {:id => 1, :confirm => 1}
     assert_redirected_to :controller => 'projects',
diff --git a/test/helpers/application_helper_test.rb b/test/helpers/application_helper_test.rb
index 9abf47fa7..552eb210f 100644
--- a/test/helpers/application_helper_test.rb
+++ b/test/helpers/application_helper_test.rb
@@ -190,7 +190,6 @@ RAW
   end
 
   def test_attached_images_filename_extension
-    set_tmp_attachments_directory
     a1 = Attachment.new(
             :container => Issue.find(1),
             :file => mock_file_with_options({:original_filename => "testtest.JPG"}),
@@ -264,6 +263,7 @@ RAW
     }
     attachments = [a1, a2]
     to_test.each { |text, result| assert_equal "<p>#{result}</p>", textilizable(text, :attachments => attachments) }
+  ensure
     set_tmp_attachments_directory
   end
 
@@ -722,7 +722,6 @@ RAW
   end
 
   def test_attachment_link_should_link_to_latest_attachment
-    set_tmp_attachments_directory
     a1 = Attachment.generate!(:filename => "test.txt", :created_on => 1.hour.ago)
     a2 = Attachment.generate!(:filename => "test.txt")
     result = link_to("test.txt", "/attachments/#{a2.id}",
diff --git a/test/helpers/journals_helper_test.rb b/test/helpers/journals_helper_test.rb
index 2e54a2a29..bda4945f9 100644
--- a/test/helpers/journals_helper_test.rb
+++ b/test/helpers/journals_helper_test.rb
@@ -32,6 +32,7 @@ class JournalsHelperTest < Redmine::HelperTest
            :versions
 
   def test_journal_thumbnail_attachments_should_return_thumbnailable_attachments
+    set_tmp_attachments_directory
     issue = Issue.generate!
 
     journal = new_record(Journal) do
diff --git a/test/integration/attachments_test.rb b/test/integration/attachments_test.rb
index 0e6336998..de5bca57f 100644
--- a/test/integration/attachments_test.rb
+++ b/test/integration/attachments_test.rb
@@ -152,7 +152,6 @@ class AttachmentsTest < Redmine::IntegrationTest
     get "/attachments/download/4"
     assert_response :success
     assert_not_nil response.headers["X-Sendfile"]
-
   ensure
     set_tmp_attachments_directory
   end
diff --git a/test/system/issues_test.rb b/test/system/issues_test.rb
index 28eccedbc..3cbe61840 100644
--- a/test/system/issues_test.rb
+++ b/test/system/issues_test.rb
@@ -149,8 +149,6 @@ class IssuesTest < ApplicationSystemTestCase
     end
     assert_equal 1, issue.attachments.count
     assert_equal 'Some description', issue.attachments.first.description
-  ensure
-    set_fixtures_attachments_directory
   end
 
   def test_create_issue_with_new_target_version
diff --git a/test/unit/attachment_test.rb b/test/unit/attachment_test.rb
index 2605f03f0..fbbe71fbe 100644
--- a/test/unit/attachment_test.rb
+++ b/test/unit/attachment_test.rb
@@ -344,6 +344,8 @@ class AttachmentTest < ActiveSupport::TestCase
     assert attachment.readable?
     attachment.update_digest_to_sha256!
     assert_equal 'ac5c6e99a21ae74b2e3f5b8e5b568be1b9107cd7153d139e822b9fe5caf50938', attachment.digest
+  ensure
+    set_tmp_attachments_directory
   end
 
   def test_update_attachments
@@ -403,7 +405,7 @@ class AttachmentTest < ActiveSupport::TestCase
     assert_equal 17, la1.id
     la2 = Attachment.latest_attach([a1, a2], "Testfile.PNG")
     assert_equal 17, la2.id
-
+  ensure
     set_tmp_attachments_directory
   end
 
@@ -444,6 +446,8 @@ class AttachmentTest < ActiveSupport::TestCase
           assert File.exist?(thumbnail)
         end
       end
+    ensure
+      set_tmp_attachments_directory
     end
 
     def test_should_reuse_thumbnail
@@ -490,6 +494,8 @@ class AttachmentTest < ActiveSupport::TestCase
       set_fixtures_attachments_directory
       attachment = Attachment.find(16)
       assert_nil attachment.thumbnail
+    ensure
+      set_tmp_attachments_directory
     end
 
     def test_thumbnail_should_be_at_least_of_requested_size
@@ -508,6 +514,8 @@ class AttachmentTest < ActiveSupport::TestCase
         assert_equal "8e0294de2441577c529f170b6fb8f638_2654_#{generated_size}.thumb",
           File.basename(thumbnail)
       end
+    ensure
+      set_tmp_attachments_directory
     end
   else
     puts '(ImageMagick convert not available)'
diff --git a/test/unit/board_test.rb b/test/unit/board_test.rb
index 3f7679320..52cc37779 100644
--- a/test/unit/board_test.rb
+++ b/test/unit/board_test.rb
@@ -93,6 +93,7 @@ class BoardTest < ActiveSupport::TestCase
   end
 
   def test_destroy
+    set_tmp_attachments_directory
     board = Board.find(1)
     assert_difference 'Message.count', -6 do
       assert_difference 'Attachment.count', -1 do
diff --git a/test/unit/lib/redmine/export/pdf_test.rb b/test/unit/lib/redmine/export/pdf_test.rb
index 095dcfb55..3bad1d8d9 100644
--- a/test/unit/lib/redmine/export/pdf_test.rb
+++ b/test/unit/lib/redmine/export/pdf_test.rb
@@ -69,9 +69,8 @@ class PdfTest < ActiveSupport::TestCase
   end
 
   def test_attach
+    set_fixtures_attachments_directory
     ["CP932", "SJIS"].each do |encoding|
-      set_fixtures_attachments_directory
-
       str2 = "\x83e\x83X\x83g".b
 
       a1 = Attachment.find(17)
@@ -99,8 +98,8 @@ class PdfTest < ActiveSupport::TestCase
       assert_nil aa1
       aa2 = Redmine::Export::PDF::RDMPdfEncoding::attach(Attachment.all, "test#{str2}.png", encoding)
       assert_nil aa2
-
-      set_tmp_attachments_directory
     end
+  ensure
+    set_tmp_attachments_directory
   end
 end
diff --git a/test/unit/mail_handler_test.rb b/test/unit/mail_handler_test.rb
index 8d7b022b9..0a0867a6f 100644
--- a/test/unit/mail_handler_test.rb
+++ b/test/unit/mail_handler_test.rb
@@ -542,6 +542,7 @@ class MailHandlerTest < ActiveSupport::TestCase
   end
 
   def test_add_issue_from_apple_mail
+    set_tmp_attachments_directory
     issue = submit_email(
               'apple_mail_with_attachment.eml',
               :issue => {:project => 'ecookbook'}
@@ -558,6 +559,7 @@ class MailHandlerTest < ActiveSupport::TestCase
   end
 
   def test_thunderbird_with_attachment_ja
+    set_tmp_attachments_directory
     issue = submit_email(
               'thunderbird_with_attachment_ja.eml',
               :issue => {:project => 'ecookbook'}
@@ -582,6 +584,7 @@ class MailHandlerTest < ActiveSupport::TestCase
   end
 
   def test_gmail_with_attachment_ja
+    set_tmp_attachments_directory
     issue = submit_email(
               'gmail_with_attachment_ja.eml',
               :issue => {:project => 'ecookbook'}
@@ -597,6 +600,7 @@ class MailHandlerTest < ActiveSupport::TestCase
   end
 
   def test_thunderbird_with_attachment_latin1
+    set_tmp_attachments_directory
     issue = submit_email(
               'thunderbird_with_attachment_iso-8859-1.eml',
               :issue => {:project => 'ecookbook'}
@@ -615,6 +619,7 @@ class MailHandlerTest < ActiveSupport::TestCase
   end
 
   def test_gmail_with_attachment_latin1
+    set_tmp_attachments_directory
     issue = submit_email(
               'gmail_with_attachment_iso-8859-1.eml',
               :issue => {:project => 'ecookbook'}
@@ -633,6 +638,7 @@ class MailHandlerTest < ActiveSupport::TestCase
   end
 
   def test_mail_with_attachment_latin2
+    set_tmp_attachments_directory
     issue = submit_email(
               'ticket_with_text_attachment_iso-8859-2.eml',
               :issue => {:project => 'ecookbook'}
@@ -986,6 +992,7 @@ class MailHandlerTest < ActiveSupport::TestCase
   end
 
   def test_reply_to_a_nonexistent_issue
+    set_tmp_attachments_directory
     Issue.find(2).destroy
     assert_no_difference 'Issue.count' do
       assert_no_difference 'Journal.count' do
diff --git a/test/unit/message_test.rb b/test/unit/message_test.rb
index 5bbb2190c..e714e09ae 100644
--- a/test/unit/message_test.rb
+++ b/test/unit/message_test.rb
@@ -108,6 +108,7 @@ class MessageTest < ActiveSupport::TestCase
   end
 
   def test_destroy_topic
+    set_tmp_attachments_directory
     message = Message.find(1)
     board = message.board
     topics_count, messages_count = board.topics_count, board.messages_count
diff --git a/test/unit/project_copy_test.rb b/test/unit/project_copy_test.rb
index fb07d6b65..eac3aa8bf 100644
--- a/test/unit/project_copy_test.rb
+++ b/test/unit/project_copy_test.rb
@@ -55,6 +55,7 @@ class ProjectCopyTest < ActiveSupport::TestCase
   end
 
   test "#copy should copy project attachments" do
+    set_tmp_attachments_directory
     Attachment.create!(:container => @source_project, :file => uploaded_test_file("testfile.txt", "text/plain"), :author_id => 1)
     assert @project.copy(@source_project)
 
@@ -207,6 +208,7 @@ class ProjectCopyTest < ActiveSupport::TestCase
   end
 
   test "#copy should copy issue attachments" do
+    set_tmp_attachments_directory
     issue = Issue.generate!(:subject => "copy with attachment", :tracker_id => 1, :project_id => @source_project.id)
     Attachment.create!(:container => issue, :file => uploaded_test_file("testfile.txt", "text/plain"), :author_id => 1)
     @source_project.issues << issue
@@ -296,6 +298,7 @@ class ProjectCopyTest < ActiveSupport::TestCase
   end
 
   test "#copy should copy version attachments" do
+    set_tmp_attachments_directory
     version = Version.generate!(:name => "copy with attachment")
     Attachment.create!(:container => version, :file => uploaded_test_file("testfile.txt", "text/plain"), :author_id => 1)
     @source_project.versions << version
@@ -378,6 +381,7 @@ class ProjectCopyTest < ActiveSupport::TestCase
   end
 
   test "#copy should copy document attachments" do
+    set_tmp_attachments_directory
     document = Document.generate!(:title => "copy with attachment", :category_id => 1, :project_id => @source_project.id)
     Attachment.create!(:container => document, :file => uploaded_test_file("testfile.txt", "text/plain"), :author_id => 1)
     @source_project.documents << document
diff --git a/test/unit/user_test.rb b/test/unit/user_test.rb
index 519de8b04..da9fbe7ed 100644
--- a/test/unit/user_test.rb
+++ b/test/unit/user_test.rb
@@ -262,6 +262,7 @@ class UserTest < ActiveSupport::TestCase
   end
 
   def test_destroy_should_update_attachments
+    set_tmp_attachments_directory
     attachment = Attachment.create!(:container => Project.find(1),
       :file => uploaded_test_file("testfile.txt", "text/plain"),
       :author_id => 2)
diff --git a/test/unit/wiki_page_test.rb b/test/unit/wiki_page_test.rb
index f3fe4fbbd..6092e3fd5 100644
--- a/test/unit/wiki_page_test.rb
+++ b/test/unit/wiki_page_test.rb
@@ -143,6 +143,7 @@ class WikiPageTest < ActiveSupport::TestCase
   end
 
   def test_destroy_should_delete_content_and_its_versions
+    set_tmp_attachments_directory
     page = WikiPage.find(1)
     assert_difference 'WikiPage.count', -1 do
       assert_difference 'WikiContent.count', -1 do
diff --git a/test/unit/wiki_test.rb b/test/unit/wiki_test.rb
index b4ecd29bb..d4688569d 100644
--- a/test/unit/wiki_test.rb
+++ b/test/unit/wiki_test.rb
@@ -103,6 +103,7 @@ class WikiTest < ActiveSupport::TestCase
   end
 
   def test_destroy_should_remove_redirects_from_the_wiki
+    set_tmp_attachments_directory
     WikiRedirect.create!(:wiki_id => 1, :title => 'Foo', :redirects_to_wiki_id => 2, :redirects_to => 'Bar')
 
     Wiki.find(1).destroy
@@ -110,6 +111,7 @@ class WikiTest < ActiveSupport::TestCase
   end
 
   def test_destroy_should_remove_redirects_to_the_wiki
+    set_tmp_attachments_directory
     WikiRedirect.create!(:wiki_id => 2, :title => 'Foo', :redirects_to_wiki_id => 1, :redirects_to => 'Bar')
 
     Wiki.find(1).destroy