Don't close systemd activated socket on pumactl restart (#2563)

Closes #2504

History.md

@@ -1,3 +1,12 @@
+## Master
+
+* Features
+  * Your feature goes here <Most recent on the top, like GitHub> (#Github Number)
+
+* Bugfixes
+  * Your bugfix goes here <Most recent on the top, like GitHub> (#Github Number)
+  * Don't close systemd activated socket on pumactl restart (#2563, #2504)
+
 ## 5.2.2 / 2021-02-22
 
 * Bugfixes

lib/puma/binder.rb

@@ -258,14 +258,18 @@ module Puma
       end
 
       # Also close any unused activated sockets
-      @activated_sockets.each do |key, sock|
-        logger.log "* Closing unused activated socket: #{key.join ':'}"
-        begin
-          sock.close
-        rescue SystemCallError
+      unless @activated_sockets.empty?
+        fds = @ios.map(&:to_i)
+        @activated_sockets.each do |key, sock|
+          next if fds.include? sock.to_i
+          logger.log "* Closing unused activated socket: #{key.first}://#{key[1..-1].join ':'}"
+          begin
+            sock.close
+          rescue SystemCallError
+          end
+          # We have to unlink a unix socket path that's not being used
+          File.unlink key[1] if key.first == :unix
         end
-        # We have to unlink a unix socket path that's not being used
-        File.unlink key[1] if key[0] == :unix
       end
     end