Don't allow users to be added to a channel they are not in the team of (#3246)

store/sql_team_store.go

@@ -4,6 +4,8 @@
 package store
 
 import (
+	"database/sql"
+
 	"github.com/mattermost/platform/model"
 	"github.com/mattermost/platform/utils"
 )
@@ -420,7 +422,11 @@ func (s SqlTeamStore) GetMember(teamId string, userId string) StoreChannel {
 		var member model.TeamMember
 		err := s.GetReplica().SelectOne(&member, "SELECT * FROM TeamMembers WHERE TeamId = :TeamId AND UserId = :UserId", map[string]interface{}{"TeamId": teamId, "UserId": userId})
 		if err != nil {
-			result.Err = model.NewLocAppError("SqlTeamStore.GetMember", "store.sql_team.get_member.app_error", nil, "teamId="+teamId+" userId="+userId+" "+err.Error())
+			if err == sql.ErrNoRows {
+				result.Err = model.NewLocAppError("SqlTeamStore.GetMember", "store.sql_team.get_member.missing.app_error", nil, "teamId="+teamId+" userId="+userId+" "+err.Error())
+			} else {
+				result.Err = model.NewLocAppError("SqlTeamStore.GetMember", "store.sql_team.get_member.app_error", nil, "teamId="+teamId+" userId="+userId+" "+err.Error())
+			}
 		} else {
 			result.Data = member
 		}