MM-27572 permissions regression (#15215)

* Fix regression in HasPermissionToTeam

* Removing unessisary special case + verify system admins always have permissions.

* Fixing testing and bad cleanup.

app/authorization.go

@@ -148,7 +148,9 @@ func (a *App) HasPermissionToTeam(askingUserId string, teamId string, permission
 	}
 	teamMember, _ := a.GetTeamMember(teamId, askingUserId)
 	if teamMember != nil && teamMember.DeleteAt == 0 {
-		return a.RolesGrantPermission(teamMember.GetRoles(), permission.Id)
+		if a.RolesGrantPermission(teamMember.GetRoles(), permission.Id) {
+			return true
+		}
 	}
 	return a.HasPermissionTo(askingUserId, permission)
 }

app/authorization_test.go

@@ -48,14 +48,14 @@ func TestHasPermissionToTeam(t *testing.T) {
 	defer th.TearDown()
 
 	assert.True(t, th.App.HasPermissionToTeam(th.BasicUser.Id, th.BasicTeam.Id, model.PERMISSION_LIST_TEAM_CHANNELS))
-
 	th.RemoveUserFromTeam(th.BasicUser, th.BasicTeam)
-
 	assert.False(t, th.App.HasPermissionToTeam(th.BasicUser.Id, th.BasicTeam.Id, model.PERMISSION_LIST_TEAM_CHANNELS))
 
+	assert.True(t, th.App.HasPermissionToTeam(th.SystemAdminUser.Id, th.BasicTeam.Id, model.PERMISSION_LIST_TEAM_CHANNELS))
 	th.LinkUserToTeam(th.SystemAdminUser, th.BasicTeam)
 	assert.True(t, th.App.HasPermissionToTeam(th.SystemAdminUser.Id, th.BasicTeam.Id, model.PERMISSION_LIST_TEAM_CHANNELS))
+	th.RemovePermissionFromRole(model.PERMISSION_LIST_TEAM_CHANNELS.Id, model.TEAM_USER_ROLE_ID)
+	assert.True(t, th.App.HasPermissionToTeam(th.SystemAdminUser.Id, th.BasicTeam.Id, model.PERMISSION_LIST_TEAM_CHANNELS))
 	th.RemoveUserFromTeam(th.SystemAdminUser, th.BasicTeam)
-	// This used to fail before MM-26015
 	assert.True(t, th.App.HasPermissionToTeam(th.SystemAdminUser.Id, th.BasicTeam.Id, model.PERMISSION_LIST_TEAM_CHANNELS))
 }