[bugfix] Stop some statuses from being home timelined when they shouldn't be (#585)

* recursively check timelineability of parent status

* check following status creator

* add tests for hometimelineability (whew)

* add test with mix of public + unlocked vis

2 files changed, 328 insertions, 9 deletions

diff --git a/internal/visibility/statushometimelineable.go b/internal/visibility/statushometimelineable.go
index 62004cb5f..af871bcaa 100644
--- a/internal/visibility/statushometimelineable.go
+++ b/internal/visibility/statushometimelineable.go
@@ -33,7 +33,7 @@ func (f *filter) StatusHometimelineable(ctx context.Context, targetStatus *gtsmo
 	})
 
 	// status owner should always be able to see their own status in their timeline so we can return early if this is the case
-	if timelineOwnerAccount != nil && targetStatus.AccountID == timelineOwnerAccount.ID {
+	if targetStatus.AccountID == timelineOwnerAccount.ID {
 		return true, nil
 	}
 
@@ -54,13 +54,29 @@ func (f *filter) StatusHometimelineable(ctx context.Context, targetStatus *gtsmo
 		}
 	}
 
+	// check we follow the originator of the status
+	if targetStatus.Account == nil {
+		tsa, err := f.db.GetAccountByID(ctx, targetStatus.AccountID)
+		if err != nil {
+			return false, fmt.Errorf("StatusHometimelineable: error getting status author account with id %s: %s", targetStatus.AccountID, err)
+		}
+		targetStatus.Account = tsa
+	}
+	following, err := f.db.IsFollowing(ctx, timelineOwnerAccount, targetStatus.Account)
+	if err != nil {
+		return false, fmt.Errorf("StatusHometimelineable: error checking if %s follows %s: %s", timelineOwnerAccount.ID, targetStatus.AccountID, err)
+	}
+	if !following {
+		return false, nil
+	}
+
 	// Don't timeline a status whose parent hasn't been dereferenced yet or can't be dereferenced.
 	// If we have the reply to URI but don't have an ID for the replied-to account or the replied-to status in our database, we haven't dereferenced it yet.
 	if targetStatus.InReplyToURI != "" && (targetStatus.InReplyToID == "" || targetStatus.InReplyToAccountID == "") {
 		return false, nil
 	}
 
-	// if a status replies to an ID we know in the database, we need to make sure we also follow the replied-to status owner account
+	// if a status replies to an ID we know in the database, we need to check that parent status too
 	if targetStatus.InReplyToID != "" {
 		// pin the reply to status on to this status if it hasn't been done already
 		if targetStatus.InReplyTo == nil {
@@ -81,18 +97,16 @@ func (f *filter) StatusHometimelineable(ctx context.Context, targetStatus *gtsmo
 		}
 
 		// if it's a reply to the timelineOwnerAccount, we don't need to check if the timelineOwnerAccount follows itself, just return true, they can see it
-		if targetStatus.AccountID == timelineOwnerAccount.ID {
+		if targetStatus.InReplyToAccountID == timelineOwnerAccount.ID {
 			return true, nil
 		}
 
-		// the replied-to account != timelineOwnerAccount, so make sure the timelineOwnerAccount follows the replied-to account
-		follows, err := f.db.IsFollowing(ctx, timelineOwnerAccount, targetStatus.InReplyToAccount)
+		// make sure the parent status is also home timelineable, otherwise we shouldn't timeline this one either
+		parentStatusTimelineable, err := f.StatusHometimelineable(ctx, targetStatus.InReplyTo, timelineOwnerAccount)
 		if err != nil {
-			return false, fmt.Errorf("StatusHometimelineable: error checking follow from account %s to account %s: %s", timelineOwnerAccount.ID, targetStatus.InReplyToAccountID, err)
+			return false, fmt.Errorf("StatusHometimelineable: error checking timelineability of parent status %s of status %s: %s", targetStatus.InReplyToID, targetStatus.ID, err)
 		}
-
-		// we don't want to timeline a reply to a status whose owner isn't followed by the requesting account
-		if !follows {
+		if !parentStatusTimelineable {
 			return false, nil
 		}
 	}
diff --git a/internal/visibility/statushometimelineable_test.go b/internal/visibility/statushometimelineable_test.go
new file mode 100644
index 000000000..6161c52c0
--- /dev/null
+++ b/internal/visibility/statushometimelineable_test.go
@@ -0,0 +1,305 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2022 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package visibility_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+	"github.com/superseriousbusiness/gotosocial/internal/ap"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/testrig"
+)
+
+type StatusStatusHometimelineableTestSuite struct {
+	FilterStandardTestSuite
+}
+
+func (suite *StatusStatusHometimelineableTestSuite) TestOwnStatusHometimelineable() {
+	testStatus := suite.testStatuses["local_account_1_status_1"]
+	testAccount := suite.testAccounts["local_account_1"]
+	ctx := context.Background()
+
+	timelineable, err := suite.filter.StatusHometimelineable(ctx, testStatus, testAccount)
+	suite.NoError(err)
+
+	suite.True(timelineable)
+}
+
+func (suite *StatusStatusHometimelineableTestSuite) TestFollowingStatusHometimelineable() {
+	testStatus := suite.testStatuses["local_account_2_status_1"]
+	testAccount := suite.testAccounts["local_account_1"]
+	ctx := context.Background()
+
+	timelineable, err := suite.filter.StatusHometimelineable(ctx, testStatus, testAccount)
+	suite.NoError(err)
+
+	suite.True(timelineable)
+}
+
+func (suite *StatusStatusHometimelineableTestSuite) TestNotFollowingStatusHometimelineable() {
+	testStatus := suite.testStatuses["remote_account_1_status_1"]
+	testAccount := suite.testAccounts["local_account_1"]
+	ctx := context.Background()
+
+	timelineable, err := suite.filter.StatusHometimelineable(ctx, testStatus, testAccount)
+	suite.NoError(err)
+
+	suite.False(timelineable)
+}
+
+func (suite *StatusStatusHometimelineableTestSuite) TestChainReplyFollowersOnly() {
+	ctx := context.Background()
+
+	// This scenario makes sure that we don't timeline a status which is a followers-only
+	// reply to a followers-only status TO A FOLLOWERS-ONLY STATUS owned by someone the
+	// timeline owner account doesn't follow.
+	//
+	// In other words, remote_account_1 posts a followers-only status, which local_account_1 replies to;
+	// THEN, local_account_1 replies to their own reply. We don't want this last status to appear
+	// in the timeline of local_account_2, even though they follow local_account_1, because they
+	// *don't* follow remote_account_1.
+	//
+	// See: https://github.com/superseriousbusiness/gotosocial/issues/501
+
+	originalStatusParent := suite.testAccounts["remote_account_1"]
+	replyingAccount := suite.testAccounts["local_account_1"]
+	timelineOwnerAccount := suite.testAccounts["local_account_2"]
+
+	// put a followers-only status by remote_account_1 in the db
+	originalStatus := &gtsmodel.Status{
+		ID:                       "01G3957TS7XE2CMDKFG3MZPWAF",
+		URI:                      "http://fossbros-anonymous.io/users/foss_satan/statuses/01G3957TS7XE2CMDKFG3MZPWAF",
+		URL:                      "http://fossbros-anonymous.io/@foss_satan/statuses/01G3957TS7XE2CMDKFG3MZPWAF",
+		Content:                  "didn't expect dog",
+		CreatedAt:                testrig.TimeMustParse("2021-09-20T12:40:37+02:00"),
+		UpdatedAt:                testrig.TimeMustParse("2021-09-20T12:40:37+02:00"),
+		Local:                    false,
+		AccountURI:               "http://fossbros-anonymous.io/users/foss_satan",
+		AccountID:                originalStatusParent.ID,
+		InReplyToID:              "",
+		InReplyToAccountID:       "",
+		InReplyToURI:             "",
+		BoostOfID:                "",
+		ContentWarning:           "",
+		Visibility:               gtsmodel.VisibilityFollowersOnly,
+		Sensitive:                false,
+		Language:                 "en",
+		CreatedWithApplicationID: "",
+		Federated:                true,
+		Boostable:                true,
+		Replyable:                true,
+		Likeable:                 true,
+		ActivityStreamsType:      ap.ObjectNote,
+	}
+	if err := suite.db.PutStatus(ctx, originalStatus); err != nil {
+		suite.FailNow(err.Error())
+	}
+	// this status should not be hometimelineable for local_account_2
+	originalStatusTimelineable, err := suite.filter.StatusHometimelineable(ctx, originalStatus, timelineOwnerAccount)
+	suite.NoError(err)
+	suite.False(originalStatusTimelineable)
+
+	// now a followers-only reply from zork
+	firstReplyStatus := &gtsmodel.Status{
+		ID:                       "01G395ESAYPK9161QSQEZKATJN",
+		URI:                      "http://localhost:8080/users/the_mighty_zork/statuses/01G395ESAYPK9161QSQEZKATJN",
+		URL:                      "http://localhost:8080/@the_mighty_zork/statuses/01G395ESAYPK9161QSQEZKATJN",
+		Content:                  "nbnbdy expects dog",
+		CreatedAt:                testrig.TimeMustParse("2021-09-20T12:41:37+02:00"),
+		UpdatedAt:                testrig.TimeMustParse("2021-09-20T12:41:37+02:00"),
+		Local:                    false,
+		AccountURI:               "http://localhost:8080/users/the_mighty_zork",
+		AccountID:                replyingAccount.ID,
+		InReplyToID:              originalStatus.ID,
+		InReplyToAccountID:       originalStatusParent.ID,
+		InReplyToURI:             originalStatus.URI,
+		BoostOfID:                "",
+		ContentWarning:           "",
+		Visibility:               gtsmodel.VisibilityFollowersOnly,
+		Sensitive:                false,
+		Language:                 "en",
+		CreatedWithApplicationID: "",
+		Federated:                true,
+		Boostable:                true,
+		Replyable:                true,
+		Likeable:                 true,
+		ActivityStreamsType:      ap.ObjectNote,
+	}
+	if err := suite.db.PutStatus(ctx, firstReplyStatus); err != nil {
+		suite.FailNow(err.Error())
+	}
+	// this status should not be hometimelineable for local_account_2
+	firstReplyStatusTimelineable, err := suite.filter.StatusHometimelineable(ctx, firstReplyStatus, timelineOwnerAccount)
+	suite.NoError(err)
+	suite.False(firstReplyStatusTimelineable)
+
+	// now a followers-only reply from zork to the status they just replied to
+	secondReplyStatus := &gtsmodel.Status{
+		ID:                       "01G395NZQZGJYRBAES57KYZ7XP",
+		URI:                      "http://localhost:8080/users/the_mighty_zork/statuses/01G395NZQZGJYRBAES57KYZ7XP",
+		URL:                      "http://localhost:8080/@the_mighty_zork/statuses/01G395NZQZGJYRBAES57KYZ7XP",
+		Content:                  "*nobody",
+		CreatedAt:                testrig.TimeMustParse("2021-09-20T12:42:37+02:00"),
+		UpdatedAt:                testrig.TimeMustParse("2021-09-20T12:42:37+02:00"),
+		Local:                    false,
+		AccountURI:               "http://localhost:8080/users/the_mighty_zork",
+		AccountID:                replyingAccount.ID,
+		InReplyToID:              firstReplyStatus.ID,
+		InReplyToAccountID:       replyingAccount.ID,
+		InReplyToURI:             firstReplyStatus.URI,
+		BoostOfID:                "",
+		ContentWarning:           "",
+		Visibility:               gtsmodel.VisibilityFollowersOnly,
+		Sensitive:                false,
+		Language:                 "en",
+		CreatedWithApplicationID: "",
+		Federated:                true,
+		Boostable:                true,
+		Replyable:                true,
+		Likeable:                 true,
+		ActivityStreamsType:      ap.ObjectNote,
+	}
+	if err := suite.db.PutStatus(ctx, secondReplyStatus); err != nil {
+		suite.FailNow(err.Error())
+	}
+
+	// this status should ALSO not be hometimelineable for local_account_2
+	secondReplyStatusTimelineable, err := suite.filter.StatusHometimelineable(ctx, secondReplyStatus, timelineOwnerAccount)
+	suite.NoError(err)
+	suite.False(secondReplyStatusTimelineable)
+}
+
+func (suite *StatusStatusHometimelineableTestSuite) TestChainReplyPublicAndUnlocked() {
+	ctx := context.Background()
+
+	// This scenario is exactly the same as the above test, but for a mix of unlocked + public posts
+
+	originalStatusParent := suite.testAccounts["remote_account_1"]
+	replyingAccount := suite.testAccounts["local_account_1"]
+	timelineOwnerAccount := suite.testAccounts["local_account_2"]
+
+	// put an unlocked status by remote_account_1 in the db
+	originalStatus := &gtsmodel.Status{
+		ID:                       "01G3957TS7XE2CMDKFG3MZPWAF",
+		URI:                      "http://fossbros-anonymous.io/users/foss_satan/statuses/01G3957TS7XE2CMDKFG3MZPWAF",
+		URL:                      "http://fossbros-anonymous.io/@foss_satan/statuses/01G3957TS7XE2CMDKFG3MZPWAF",
+		Content:                  "didn't expect dog",
+		CreatedAt:                testrig.TimeMustParse("2021-09-20T12:40:37+02:00"),
+		UpdatedAt:                testrig.TimeMustParse("2021-09-20T12:40:37+02:00"),
+		Local:                    false,
+		AccountURI:               "http://fossbros-anonymous.io/users/foss_satan",
+		AccountID:                originalStatusParent.ID,
+		InReplyToID:              "",
+		InReplyToAccountID:       "",
+		InReplyToURI:             "",
+		BoostOfID:                "",
+		ContentWarning:           "",
+		Visibility:               gtsmodel.VisibilityUnlocked,
+		Sensitive:                false,
+		Language:                 "en",
+		CreatedWithApplicationID: "",
+		Federated:                true,
+		Boostable:                true,
+		Replyable:                true,
+		Likeable:                 true,
+		ActivityStreamsType:      ap.ObjectNote,
+	}
+	if err := suite.db.PutStatus(ctx, originalStatus); err != nil {
+		suite.FailNow(err.Error())
+	}
+	// this status should not be hometimelineable for local_account_2
+	originalStatusTimelineable, err := suite.filter.StatusHometimelineable(ctx, originalStatus, timelineOwnerAccount)
+	suite.NoError(err)
+	suite.False(originalStatusTimelineable)
+
+	// now a public reply from zork
+	firstReplyStatus := &gtsmodel.Status{
+		ID:                       "01G395ESAYPK9161QSQEZKATJN",
+		URI:                      "http://localhost:8080/users/the_mighty_zork/statuses/01G395ESAYPK9161QSQEZKATJN",
+		URL:                      "http://localhost:8080/@the_mighty_zork/statuses/01G395ESAYPK9161QSQEZKATJN",
+		Content:                  "nbnbdy expects dog",
+		CreatedAt:                testrig.TimeMustParse("2021-09-20T12:41:37+02:00"),
+		UpdatedAt:                testrig.TimeMustParse("2021-09-20T12:41:37+02:00"),
+		Local:                    false,
+		AccountURI:               "http://localhost:8080/users/the_mighty_zork",
+		AccountID:                replyingAccount.ID,
+		InReplyToID:              originalStatus.ID,
+		InReplyToAccountID:       originalStatusParent.ID,
+		InReplyToURI:             originalStatus.URI,
+		BoostOfID:                "",
+		ContentWarning:           "",
+		Visibility:               gtsmodel.VisibilityPublic,
+		Sensitive:                false,
+		Language:                 "en",
+		CreatedWithApplicationID: "",
+		Federated:                true,
+		Boostable:                true,
+		Replyable:                true,
+		Likeable:                 true,
+		ActivityStreamsType:      ap.ObjectNote,
+	}
+	if err := suite.db.PutStatus(ctx, firstReplyStatus); err != nil {
+		suite.FailNow(err.Error())
+	}
+	// this status should not be hometimelineable for local_account_2
+	firstReplyStatusTimelineable, err := suite.filter.StatusHometimelineable(ctx, firstReplyStatus, timelineOwnerAccount)
+	suite.NoError(err)
+	suite.False(firstReplyStatusTimelineable)
+
+	// now an unlocked reply from zork to the status they just replied to
+	secondReplyStatus := &gtsmodel.Status{
+		ID:                       "01G395NZQZGJYRBAES57KYZ7XP",
+		URI:                      "http://localhost:8080/users/the_mighty_zork/statuses/01G395NZQZGJYRBAES57KYZ7XP",
+		URL:                      "http://localhost:8080/@the_mighty_zork/statuses/01G395NZQZGJYRBAES57KYZ7XP",
+		Content:                  "*nobody",
+		CreatedAt:                testrig.TimeMustParse("2021-09-20T12:42:37+02:00"),
+		UpdatedAt:                testrig.TimeMustParse("2021-09-20T12:42:37+02:00"),
+		Local:                    false,
+		AccountURI:               "http://localhost:8080/users/the_mighty_zork",
+		AccountID:                replyingAccount.ID,
+		InReplyToID:              firstReplyStatus.ID,
+		InReplyToAccountID:       replyingAccount.ID,
+		InReplyToURI:             firstReplyStatus.URI,
+		BoostOfID:                "",
+		ContentWarning:           "",
+		Visibility:               gtsmodel.VisibilityUnlocked,
+		Sensitive:                false,
+		Language:                 "en",
+		CreatedWithApplicationID: "",
+		Federated:                true,
+		Boostable:                true,
+		Replyable:                true,
+		Likeable:                 true,
+		ActivityStreamsType:      ap.ObjectNote,
+	}
+	if err := suite.db.PutStatus(ctx, secondReplyStatus); err != nil {
+		suite.FailNow(err.Error())
+	}
+
+	// this status should ALSO not be hometimelineable for local_account_2
+	secondReplyStatusTimelineable, err := suite.filter.StatusHometimelineable(ctx, secondReplyStatus, timelineOwnerAccount)
+	suite.NoError(err)
+	suite.False(secondReplyStatusTimelineable)
+}
+
+func TestStatusHometimelineableTestSuite(t *testing.T) {
+	suite.Run(t, new(StatusStatusHometimelineableTestSuite))
+}