Ensure only one client is managed for given window

features/manager/manage.feature

@@ -0,0 +1,14 @@
+Feature: manager client management
+
+  Background:
+    Given uhwm is running
+
+  Scenario: logs when a new client is managed
+    When a window requests to be mapped
+    Then the output must match /manage.+xclient/i
+
+  Scenario: manages a given client only once
+    When a window requests to be mapped 2 times
+    And I quit uhwm
+    Then the output must not match /manage.*\n.*manage/mi
+    And the output must not match /xerror/i

features/steps/output_steps.rb

@@ -23,6 +23,10 @@ Then /^the output must match \/([^\/]+)\/([a-z]*)$/ do |pattern, options|
   uhwm_wait_output Regexp.new(pattern, options)
 end
 
+Then /^the output must not match \/([^\/]+)\/([a-z]*)$/ do |pattern, options|
+  expect(all_output).not_to match Regexp.new(pattern, options)
+end
+
 Then /^the output must contain:$/ do |content|
   uhwm_wait_output content.to_s
 end

features/steps/run_steps.rb

@@ -27,6 +27,11 @@ When /^I tell uhwm to quit$/ do
   x_key 'alt+shift+q'
 end
 
+When /^I quit uhwm$/ do
+  x_key 'alt+shift+q'
+  assert_exit_status 0
+end
+
 Then /^the exit status must be (\d+)$/ do |exit_status|
   assert_exit_status exit_status.to_i
 end

features/steps/x_steps.rb

@@ -6,6 +6,10 @@ When /^a window requests to be mapped$/ do
   x_window_map
 end
 
+When /^a window requests to be mapped (\d+) times$/ do |times|
+  x_window_map times: times.to_i
+end
+
 Then /^it must connect to X display$/ do
   uhwm_wait_output 'Connected to'
   expect(x_socket_check uhwm_pid).to be true

lib/uh/wm/manager.rb

@@ -46,7 +46,7 @@ module Uh
       end
 
       def manage window
-        return if window.override_redirect?
+        return if window.override_redirect? || client_for(window)
         @clients << client = Client.new(window)
         @events.emit :manage, args: client
       end
@@ -83,6 +83,10 @@ module Uh
         manage event.window
       end
 
+      def client_for window
+        @clients.find { |e| e.window == window }
+      end
+
       def check_other_wm!
         Display.on_error { fail OtherWMRunningError }
         @display.listen_events INPUT_MASK

lib/uh/wm/testing/acceptance_helpers.rb

@@ -89,8 +89,9 @@ module Uh
           @x_client.window_name
         end
 
-        def x_window_map
-          x_client.map.sync
+        def x_window_map times: 1
+          times.times { x_client.map }
+          x_client.sync
         end
 
         def x_window_map_state

spec/uh/wm/manager_spec.rb

@@ -116,6 +116,11 @@ module Uh
             .and have_attributes(window: window)
         end
 
+        it 'registers new client only once for a given window' do
+          manager.manage window
+          expect { manager.manage window }.not_to change { manager.clients }
+        end
+
         it 'ignores event when window has override redirect' do
           allow(window).to receive(:override_redirect?) { true }
           expect { manager.manage window }.not_to change { manager.clients }