MM-17489: fixed racy tryExecutePluginCommand (#11780)

* MM-17489: fixed racy tryExecutePluginCommand

* PR feedback

* MM 7971 dockerhost -> localhost && docker -> docker-compose (#10872)

* replace dockerhost with localhost

* remove uneeded setup-max build step (no more dockerhost)

* changes as recommended by @cpanato

* make clean-docker with docker-compose

* added ports to docker-compose.yml (needed for osx).   ignore error for ldapadd (when already exists)

* add clean-old-docker to legacy.mk

* docker-compose stop instead of down for `make stop-docker`

* MM-17117: Updates einterface for FirstLoginSync. (#11737)

* update sampledata users passwords (#11769)

* update sampledata users passwords

* update makefile

* Tweak docker compose setup (#11785)

* fix stray dockerhost mention

* fix stray whitespace

* fix missing mattermost-redix cleanup in clean-old-docker

* absolute path to docker-compose, plus simpler ldap initialization

* allow ldapadd to fail on CI

* MM-16366 - Prevent attachment duplication on import (#11770)

* prevent attachment duplication

* improved tests

* corrected import into a new post

* WIP: a failed attempt to add tests

* remove debugging statements

* fix godoc

* enable plugins when testing

* rework reentrant unit tests

app/plugin_commands.go

@@ -97,20 +97,29 @@ func (a *App) tryExecutePluginCommand(args *model.CommandArgs) (*model.Command,
 	trigger := parts[0][1:]
 	trigger = strings.ToLower(trigger)
 
+	var matched *PluginCommand
 	a.Srv.pluginCommandsLock.RLock()
-	defer a.Srv.pluginCommandsLock.RUnlock()
-
 	for _, pc := range a.Srv.pluginCommands {
 		if (pc.Command.TeamId == "" || pc.Command.TeamId == args.TeamId) && pc.Command.Trigger == trigger {
-			if pluginsEnvironment := a.GetPluginsEnvironment(); pluginsEnvironment != nil {
-				pluginHooks, err := pluginsEnvironment.HooksForPlugin(pc.PluginId)
-				if err != nil {
-					return pc.Command, nil, model.NewAppError("ExecutePluginCommand", "model.plugin_command.error.app_error", nil, "err="+err.Error(), http.StatusInternalServerError)
-				}
-				response, appErr := pluginHooks.ExecuteCommand(a.PluginContext(), args)
-				return pc.Command, response, appErr
-			}
+			matched = pc
+			break
 		}
 	}
-	return nil, nil, nil
+	a.Srv.pluginCommandsLock.RUnlock()
+	if matched == nil {
+		return nil, nil, nil
+	}
+
+	pluginsEnvironment := a.GetPluginsEnvironment()
+	if pluginsEnvironment == nil {
+		return nil, nil, nil
+	}
+
+	pluginHooks, err := pluginsEnvironment.HooksForPlugin(matched.PluginId)
+	if err != nil {
+		return matched.Command, nil, model.NewAppError("ExecutePluginCommand", "model.plugin_command.error.app_error", nil, "err="+err.Error(), http.StatusInternalServerError)
+	}
+
+	response, appErr := pluginHooks.ExecuteCommand(a.PluginContext(), args)
+	return matched.Command, response, appErr
 }