[bugfix] 2643 bug search for account url doesnt always work when redirected (#2673)

* update activity library so dereferencer returns full response and checks *final* link to allow for redirects

* temporarily add bodged fixed library

* remove unused code

* update getAccountFeatured() to use dereferenceCollectionPage()

* make sure to release map

* perform a 2nd decode to ensure reader is empty after primary decode

* add comment explaining choice of using Decode() instead of Unmarshal()

* update embedded activity library to latest matching https://github.com/superseriousbusiness/activity/pull/21

* add checks to look for changed URI and re-check database if redirected

* update max iteration count to 512, add checks during dereferenceAncestors() for indirect URLs

* remove doubled-up code

* fix use of status instead of current

* use URIs for checking equality for security

* use the latest known URI for boost_of_uri in case original was an indirect

* add dereferenceCollection() function for dereferenceAccountFeatured()

* pull in latest github.com/superseriousbusiness/activity version (and remove the bodge!!)

* fix typo in code comments

* update decodeType() to accept a readcloser and handle body closing

* switch to checking using BoostOfID and add note why not using BoostOfURI

* ensure InReplyTo gets unset when deleting status parent in case currently stubbed

* add tests for Collection and CollectionPage iterators

17 files changed, 726 insertions, 228 deletions

diff --git a/internal/ap/ap_test.go b/internal/ap/ap_test.go
index 583a37c53..0a9f66ca6 100644
--- a/internal/ap/ap_test.go
+++ b/internal/ap/ap_test.go
@@ -18,8 +18,10 @@
 package ap_test
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"io"
 
 	"github.com/stretchr/testify/suite"
 	"github.com/superseriousbusiness/activity/pub"
@@ -187,7 +189,10 @@ func (suite *APTestSuite) noteWithHashtags1() ap.Statusable {
 	}
 }`)
 
-	statusable, err := ap.ResolveStatusable(context.Background(), noteJson)
+	statusable, err := ap.ResolveStatusable(
+		context.Background(),
+		io.NopCloser(bytes.NewReader(noteJson)),
+	)
 	if err != nil {
 		suite.FailNow(err.Error())
 	}
diff --git a/internal/ap/collections.go b/internal/ap/collections.go
index ba3887a5b..da789e179 100644
--- a/internal/ap/collections.go
+++ b/internal/ap/collections.go
@@ -26,6 +26,24 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/paging"
 )
 
+// TODO: replace must of this logic with just
+// using extractIRIs() on the iterator types.
+
+// ToCollectionIterator attempts to resolve the given vocab type as a Collection
+// like object and wrap in a standardised interface in order to iterate its contents.
+func ToCollectionIterator(t vocab.Type) (CollectionIterator, error) {
+	switch name := t.GetTypeName(); name {
+	case ObjectCollection:
+		t := t.(vocab.ActivityStreamsCollection)
+		return WrapCollection(t), nil
+	case ObjectOrderedCollection:
+		t := t.(vocab.ActivityStreamsOrderedCollection)
+		return WrapOrderedCollection(t), nil
+	default:
+		return nil, fmt.Errorf("%T(%s) was not Collection-like", t, name)
+	}
+}
+
 // ToCollectionPageIterator attempts to resolve the given vocab type as a CollectionPage
 // like object and wrap in a standardised interface in order to iterate its contents.
 func ToCollectionPageIterator(t vocab.Type) (CollectionPageIterator, error) {
@@ -41,6 +59,16 @@ func ToCollectionPageIterator(t vocab.Type) (CollectionPageIterator, error) {
 	}
 }
 
+// WrapCollection wraps an ActivityStreamsCollection in a standardised collection interface.
+func WrapCollection(collection vocab.ActivityStreamsCollection) CollectionIterator {
+	return &regularCollectionIterator{ActivityStreamsCollection: collection}
+}
+
+// WrapOrderedCollection wraps an ActivityStreamsOrderedCollection in a standardised collection interface.
+func WrapOrderedCollection(collection vocab.ActivityStreamsOrderedCollection) CollectionIterator {
+	return &orderedCollectionIterator{ActivityStreamsOrderedCollection: collection}
+}
+
 // WrapCollectionPage wraps an ActivityStreamsCollectionPage in a standardised collection page interface.
 func WrapCollectionPage(page vocab.ActivityStreamsCollectionPage) CollectionPageIterator {
 	return &regularCollectionPageIterator{ActivityStreamsCollectionPage: page}
@@ -51,6 +79,90 @@ func WrapOrderedCollectionPage(page vocab.ActivityStreamsOrderedCollectionPage)
 	return &orderedCollectionPageIterator{ActivityStreamsOrderedCollectionPage: page}
 }
 
+// regularCollectionIterator implements CollectionIterator
+// for the vocab.ActivitiyStreamsCollection type.
+type regularCollectionIterator struct {
+	vocab.ActivityStreamsCollection
+	items vocab.ActivityStreamsItemsPropertyIterator
+	once  bool // only init items once
+}
+
+func (iter *regularCollectionIterator) NextItem() TypeOrIRI {
+	if !iter.initItems() {
+		return nil
+	}
+	cur := iter.items
+	iter.items = iter.items.Next()
+	return cur
+}
+
+func (iter *regularCollectionIterator) PrevItem() TypeOrIRI {
+	if !iter.initItems() {
+		return nil
+	}
+	cur := iter.items
+	iter.items = iter.items.Prev()
+	return cur
+}
+
+func (iter *regularCollectionIterator) initItems() bool {
+	if iter.once {
+		return (iter.items != nil)
+	}
+	iter.once = true
+	if iter.ActivityStreamsCollection == nil {
+		return false // no page set
+	}
+	items := iter.GetActivityStreamsItems()
+	if items == nil {
+		return false // no items found
+	}
+	iter.items = items.Begin()
+	return (iter.items != nil)
+}
+
+// orderedCollectionIterator implements CollectionIterator
+// for the vocab.ActivitiyStreamsOrderedCollection type.
+type orderedCollectionIterator struct {
+	vocab.ActivityStreamsOrderedCollection
+	items vocab.ActivityStreamsOrderedItemsPropertyIterator
+	once  bool // only init items once
+}
+
+func (iter *orderedCollectionIterator) NextItem() TypeOrIRI {
+	if !iter.initItems() {
+		return nil
+	}
+	cur := iter.items
+	iter.items = iter.items.Next()
+	return cur
+}
+
+func (iter *orderedCollectionIterator) PrevItem() TypeOrIRI {
+	if !iter.initItems() {
+		return nil
+	}
+	cur := iter.items
+	iter.items = iter.items.Prev()
+	return cur
+}
+
+func (iter *orderedCollectionIterator) initItems() bool {
+	if iter.once {
+		return (iter.items != nil)
+	}
+	iter.once = true
+	if iter.ActivityStreamsOrderedCollection == nil {
+		return false // no page set
+	}
+	items := iter.GetActivityStreamsOrderedItems()
+	if items == nil {
+		return false // no items found
+	}
+	iter.items = items.Begin()
+	return (iter.items != nil)
+}
+
 // regularCollectionPageIterator implements CollectionPageIterator
 // for the vocab.ActivitiyStreamsCollectionPage type.
 type regularCollectionPageIterator struct {
diff --git a/internal/ap/collections_test.go b/internal/ap/collections_test.go
new file mode 100644
index 000000000..87a5bb057
--- /dev/null
+++ b/internal/ap/collections_test.go
@@ -0,0 +1,148 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// 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 ap_test
+
+import (
+	"net/url"
+	"slices"
+	"testing"
+
+	"github.com/superseriousbusiness/activity/pub"
+	"github.com/superseriousbusiness/activity/streams"
+	"github.com/superseriousbusiness/activity/streams/vocab"
+	"github.com/superseriousbusiness/gotosocial/internal/ap"
+)
+
+var testIteratorIRIs = [][]string{
+	{
+		"https://google.com",
+		"https://mastodon.social",
+		"http://naughty.naughty.website/heres/the/porn",
+		"https://god.monarchies.suck?yes=they&really=do",
+	},
+	{
+		// zero length
+	},
+	{
+		"https://superseriousbusiness.org",
+		"http://gotosocial.tv/@slothsgonewild",
+	},
+}
+
+func TestToCollectionIterator(t *testing.T) {
+	for _, iris := range testIteratorIRIs {
+		testToCollectionIterator(t, toCollection(iris), "", iris)
+		testToCollectionIterator(t, toOrderedCollection(iris), "", iris)
+	}
+	testToCollectionIterator(t, streams.NewActivityStreamsAdd(), "*typeadd.ActivityStreamsAdd(Add) was not Collection-like", nil)
+	testToCollectionIterator(t, streams.NewActivityStreamsBlock(), "*typeblock.ActivityStreamsBlock(Block) was not Collection-like", nil)
+}
+
+func TestToCollectionPageIterator(t *testing.T) {
+	for _, iris := range testIteratorIRIs {
+		testToCollectionPageIterator(t, toCollectionPage(iris), "", iris)
+		testToCollectionPageIterator(t, toOrderedCollectionPage(iris), "", iris)
+	}
+	testToCollectionPageIterator(t, streams.NewActivityStreamsAdd(), "*typeadd.ActivityStreamsAdd(Add) was not CollectionPage-like", nil)
+	testToCollectionPageIterator(t, streams.NewActivityStreamsBlock(), "*typeblock.ActivityStreamsBlock(Block) was not CollectionPage-like", nil)
+}
+
+func testToCollectionIterator(t *testing.T, in vocab.Type, expectErr string, expectIRIs []string) {
+	collect, err := ap.ToCollectionIterator(in)
+	if !errCheck(err, expectErr) {
+		t.Fatalf("did not return expected error: expect=%v receive=%v", expectErr, err)
+	}
+	iris := gatherFromIterator(collect)
+	if !slices.Equal(iris, expectIRIs) {
+		t.Fatalf("did not return expected iris: expect=%v receive=%v", expectIRIs, iris)
+	}
+}
+
+func testToCollectionPageIterator(t *testing.T, in vocab.Type, expectErr string, expectIRIs []string) {
+	page, err := ap.ToCollectionPageIterator(in)
+	if !errCheck(err, expectErr) {
+		t.Fatalf("did not return expected error: expect=%v receive=%v", expectErr, err)
+	}
+	iris := gatherFromIterator(page)
+	if !slices.Equal(iris, expectIRIs) {
+		t.Fatalf("did not return expected iris: expect=%v receive=%v", expectIRIs, iris)
+	}
+}
+
+func toCollection(iris []string) vocab.ActivityStreamsCollection {
+	collect := streams.NewActivityStreamsCollection()
+	collect.SetActivityStreamsItems(toItems(iris))
+	return collect
+}
+
+func toOrderedCollection(iris []string) vocab.ActivityStreamsOrderedCollection {
+	collect := streams.NewActivityStreamsOrderedCollection()
+	collect.SetActivityStreamsOrderedItems(toOrderedItems(iris))
+	return collect
+}
+
+func toCollectionPage(iris []string) vocab.ActivityStreamsCollectionPage {
+	page := streams.NewActivityStreamsCollectionPage()
+	page.SetActivityStreamsItems(toItems(iris))
+	return page
+}
+
+func toOrderedCollectionPage(iris []string) vocab.ActivityStreamsOrderedCollectionPage {
+	page := streams.NewActivityStreamsOrderedCollectionPage()
+	page.SetActivityStreamsOrderedItems(toOrderedItems(iris))
+	return page
+}
+
+func toItems(iris []string) vocab.ActivityStreamsItemsProperty {
+	items := streams.NewActivityStreamsItemsProperty()
+	for _, iri := range iris {
+		u, _ := url.Parse(iri)
+		items.AppendIRI(u)
+	}
+	return items
+}
+
+func toOrderedItems(iris []string) vocab.ActivityStreamsOrderedItemsProperty {
+	items := streams.NewActivityStreamsOrderedItemsProperty()
+	for _, iri := range iris {
+		u, _ := url.Parse(iri)
+		items.AppendIRI(u)
+	}
+	return items
+}
+
+func gatherFromIterator(iter ap.CollectionIterator) []string {
+	var iris []string
+	if iter == nil {
+		return nil
+	}
+	for item := iter.NextItem(); item != nil; item = iter.NextItem() {
+		id, _ := pub.ToId(item)
+		if id != nil {
+			iris = append(iris, id.String())
+		}
+	}
+	return iris
+}
+
+func errCheck(err error, str string) bool {
+	if err == nil {
+		return str == ""
+	}
+	return err.Error() == str
+}
diff --git a/internal/ap/interfaces.go b/internal/ap/interfaces.go
index 811e09125..fa8e8a338 100644
--- a/internal/ap/interfaces.go
+++ b/internal/ap/interfaces.go
@@ -300,6 +300,15 @@ type ReplyToable interface {
 	WithInReplyTo
 }
 
+// CollectionIterator represents the minimum interface for interacting with a
+// wrapped Collection or OrderedCollection in order to access next / prev items.
+type CollectionIterator interface {
+	vocab.Type
+
+	NextItem() TypeOrIRI
+	PrevItem() TypeOrIRI
+}
+
 // CollectionPageIterator represents the minimum interface for interacting with a wrapped
 // CollectionPage or OrderedCollectionPage in order to access both next / prev pages and items.
 type CollectionPageIterator interface {
diff --git a/internal/ap/resolve.go b/internal/ap/resolve.go
index 20a858900..b2e866b6f 100644
--- a/internal/ap/resolve.go
+++ b/internal/ap/resolve.go
@@ -22,8 +22,8 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
-	"sync"
 
 	"github.com/superseriousbusiness/activity/pub"
 	"github.com/superseriousbusiness/activity/streams"
@@ -31,61 +31,6 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 )
 
-// mapPool is a memory pool of maps for JSON decoding.
-var mapPool = sync.Pool{
-	New: func() any {
-		return make(map[string]any)
-	},
-}
-
-// getMap acquires a map from memory pool.
-func getMap() map[string]any {
-	m := mapPool.Get().(map[string]any) //nolint
-	return m
-}
-
-// putMap clears and places map back in pool.
-func putMap(m map[string]any) {
-	if len(m) > int(^uint8(0)) {
-		// don't pool overly
-		// large maps.
-		return
-	}
-	for k := range m {
-		delete(m, k)
-	}
-	mapPool.Put(m)
-}
-
-// bytesToType tries to parse the given bytes slice
-// as a JSON ActivityPub type, failing if the input
-// bytes are not parseable as JSON, or do not parse
-// to an ActivityPub that we can understand.
-//
-// The given map pointer will also be populated with
-// the parsed JSON, to allow further processing.
-func bytesToType(
-	ctx context.Context,
-	b []byte,
-	raw map[string]any,
-) (vocab.Type, error) {
-	// Unmarshal the raw JSON bytes into a "raw" map.
-	// This will fail if the input is not parseable
-	// as JSON; eg., a remote has returned HTML as a
-	// fallback response to an ActivityPub JSON request.
-	if err := json.Unmarshal(b, &raw); err != nil {
-		return nil, gtserror.NewfAt(3, "error unmarshalling bytes into json: %w", err)
-	}
-
-	// Resolve an ActivityStreams type.
-	t, err := streams.ToType(ctx, raw)
-	if err != nil {
-		return nil, gtserror.NewfAt(3, "error resolving json into ap vocab type: %w", err)
-	}
-
-	return t, nil
-}
-
 // ResolveActivity is a util function for pulling a pub.Activity type out of an incoming request body,
 // returning the resolved activity type, error and whether to accept activity (false = transient i.e. ignore).
 func ResolveIncomingActivity(r *http.Request) (pub.Activity, bool, gtserror.WithCode) {
@@ -93,25 +38,23 @@ func ResolveIncomingActivity(r *http.Request) (pub.Activity, bool, gtserror.With
 	// destination.
 	raw := getMap()
 
-	// Tidy up when done.
-	defer r.Body.Close()
+	// Decode data as JSON into 'raw' map
+	// and get the resolved AS vocab.Type.
+	// (this handles close of request body).
+	t, err := decodeType(r.Context(), r.Body, raw)
 
-	// Decode the JSON body stream into "raw" map.
-	if err := json.NewDecoder(r.Body).Decode(&raw); err != nil {
-		err := gtserror.Newf("error decoding json: %w", err)
-		return nil, false, gtserror.NewErrorInternalError(err)
-	}
-
-	// Resolve "raw" JSON to vocab.Type.
-	t, err := streams.ToType(r.Context(), raw)
 	if err != nil {
+		// NOTE: if the error here was due to the response body
+		// ending early, the connection will have broken so it
+		// doesn't matter if we try to return 400 or 500, the
+		// error is mainly for our logging. tl;dr there's not a
+		// huge need to differentiate between those error types.
+
 		if !streams.IsUnmatchedErr(err) {
 			err := gtserror.Newf("error matching json to type: %w", err)
 			return nil, false, gtserror.NewErrorInternalError(err)
 		}
 
-		// Respond with bad request; we just couldn't
-		// match the type to one that we know about.
 		const text = "body json not resolvable as ActivityStreams type"
 		return nil, false, gtserror.NewErrorBadRequest(errors.New(text), text)
 	}
@@ -142,18 +85,19 @@ func ResolveIncomingActivity(r *http.Request) (pub.Activity, bool, gtserror.With
 	return activity, true, nil
 }
 
-// ResolveStatusable tries to resolve the given bytes into an ActivityPub Statusable representation.
-// It will then perform normalization on the Statusable.
+// ResolveStatusable tries to resolve the response data as an ActivityPub
+// Statusable representation. It will then perform normalization on the Statusable.
 //
 // Works for: Article, Document, Image, Video, Note, Page, Event, Place, Profile, Question.
-func ResolveStatusable(ctx context.Context, b []byte) (Statusable, error) {
+func ResolveStatusable(ctx context.Context, body io.ReadCloser) (Statusable, error) {
 	// Get "raw" map
 	// destination.
 	raw := getMap()
 
-	// Convert raw bytes to an AP type.
-	// This will also populate the map.
-	t, err := bytesToType(ctx, b, raw)
+	// Decode data as JSON into 'raw' map
+	// and get the resolved AS vocab.Type.
+	// (this handles close of given body).
+	t, err := decodeType(ctx, body, raw)
 	if err != nil {
 		return nil, gtserror.SetWrongType(err)
 	}
@@ -183,18 +127,19 @@ func ResolveStatusable(ctx context.Context, b []byte) (Statusable, error) {
 	return statusable, nil
 }
 
-// ResolveStatusable tries to resolve the given bytes into an ActivityPub Accountable representation.
-// It will then perform normalization on the Accountable.
+// ResolveAccountable tries to resolve the given reader into an ActivityPub
+// Accountable representation. It will then perform normalization on the Accountable.
 //
 // Works for: Application, Group, Organization, Person, Service
-func ResolveAccountable(ctx context.Context, b []byte) (Accountable, error) {
+func ResolveAccountable(ctx context.Context, body io.ReadCloser) (Accountable, error) {
 	// Get "raw" map
 	// destination.
 	raw := getMap()
 
-	// Convert raw bytes to an AP type.
-	// This will also populate the map.
-	t, err := bytesToType(ctx, b, raw)
+	// Decode data as JSON into 'raw' map
+	// and get the resolved AS vocab.Type.
+	// (this handles close of given body).
+	t, err := decodeType(ctx, body, raw)
 	if err != nil {
 		return nil, gtserror.SetWrongType(err)
 	}
@@ -213,3 +158,104 @@ func ResolveAccountable(ctx context.Context, b []byte) (Accountable, error) {
 
 	return accountable, nil
 }
+
+// ResolveCollection tries to resolve the given reader into an ActivityPub Collection-like
+// representation, then wrapping as abstracted iterator. Works for: Collection, OrderedCollection.
+func ResolveCollection(ctx context.Context, body io.ReadCloser) (CollectionIterator, error) {
+	// Get "raw" map
+	// destination.
+	raw := getMap()
+
+	// Decode data as JSON into 'raw' map
+	// and get the resolved AS vocab.Type.
+	// (this handles close of given body).
+	t, err := decodeType(ctx, body, raw)
+	if err != nil {
+		return nil, gtserror.SetWrongType(err)
+	}
+
+	// Release.
+	putMap(raw)
+
+	// Cast as as Collection-like.
+	return ToCollectionIterator(t)
+}
+
+// ResolveCollectionPage tries to resolve the given reader into an ActivityPub CollectionPage-like
+// representation, then wrapping as abstracted iterator. Works for: CollectionPage, OrderedCollectionPage.
+func ResolveCollectionPage(ctx context.Context, body io.ReadCloser) (CollectionPageIterator, error) {
+	// Get "raw" map
+	// destination.
+	raw := getMap()
+
+	// Decode data as JSON into 'raw' map
+	// and get the resolved AS vocab.Type.
+	// (this handles close of given body).
+	t, err := decodeType(ctx, body, raw)
+	if err != nil {
+		return nil, gtserror.SetWrongType(err)
+	}
+
+	// Release.
+	putMap(raw)
+
+	// Cast as as CollectionPage-like.
+	return ToCollectionPageIterator(t)
+}
+
+// emptydest is an empty JSON decode
+// destination useful for "noop" decodes
+// to check underlying reader is empty.
+var emptydest = &struct{}{}
+
+// decodeType tries to read and parse the data
+// at provided io.ReadCloser as a JSON ActivityPub
+// type, failing if not parseable as JSON or not
+// resolveable as one of our known AS types.
+//
+// NOTE: this function handles closing
+// given body when it is finished with.
+//
+// The given map pointer will also be populated with
+// the 'raw' JSON data, for further processing.
+func decodeType(
+	ctx context.Context,
+	body io.ReadCloser,
+	raw map[string]any,
+) (vocab.Type, error) {
+
+	// Wrap body in JSON decoder.
+	//
+	// We do this instead of using json.Unmarshal()
+	// so we can take advantage of the decoder's streamed
+	// check of input data as valid JSON. This means that
+	// in the cases of garbage input, or even just fallback
+	// HTML responses that were incorrectly content-type'd,
+	// we can error-out as soon as possible.
+	dec := json.NewDecoder(body)
+
+	// Unmarshal JSON source data into "raw" map.
+	if err := dec.Decode(&raw); err != nil {
+		_ = body.Close() // ensure closed.
+		return nil, gtserror.NewfAt(3, "error decoding into json: %w", err)
+	}
+
+	// Perform a secondary decode just to ensure we drained the
+	// entirety of the data source. Error indicates either extra
+	// trailing garbage, or multiple JSON values (invalid data).
+	if err := dec.Decode(emptydest); err != io.EOF {
+		_ = body.Close() // ensure closed.
+		return nil, gtserror.NewfAt(3, "data remaining after json")
+	}
+
+	// Done with body.
+	_ = body.Close()
+
+	// Resolve an ActivityStreams type.
+	t, err := streams.ToType(ctx, raw)
+	if err != nil {
+		return nil, gtserror.NewfAt(3, "error resolving json into ap vocab type: %w", err)
+	}
+
+	return t, nil
+}
diff --git a/internal/ap/resolve_test.go b/internal/ap/resolve_test.go
index bc32af7e4..aaf90ab0a 100644
--- a/internal/ap/resolve_test.go
+++ b/internal/ap/resolve_test.go
@@ -18,7 +18,9 @@
 package ap_test
 
 import (
+	"bytes"
 	"context"
+	"io"
 	"testing"
 
 	"github.com/stretchr/testify/suite"
@@ -33,7 +35,9 @@ type ResolveTestSuite struct {
 func (suite *ResolveTestSuite) TestResolveDocumentAsStatusable() {
 	b := []byte(suite.typeToJson(suite.document1))
 
-	statusable, err := ap.ResolveStatusable(context.Background(), b)
+	statusable, err := ap.ResolveStatusable(
+		context.Background(), io.NopCloser(bytes.NewReader(b)),
+	)
 	suite.NoError(err)
 	suite.NotNil(statusable)
 }
@@ -41,7 +45,9 @@ func (suite *ResolveTestSuite) TestResolveDocumentAsStatusable() {
 func (suite *ResolveTestSuite) TestResolveDocumentAsAccountable() {
 	b := []byte(suite.typeToJson(suite.document1))
 
-	accountable, err := ap.ResolveAccountable(context.Background(), b)
+	accountable, err := ap.ResolveAccountable(
+		context.Background(), io.NopCloser(bytes.NewReader(b)),
+	)
 	suite.True(gtserror.IsWrongType(err))
 	suite.EqualError(err, "ResolveAccountable: cannot resolve vocab type *typedocument.ActivityStreamsDocument as accountable")
 	suite.Nil(accountable)
@@ -51,9 +57,11 @@ func (suite *ResolveTestSuite) TestResolveHTMLAsAccountable() {
 	b := []byte(`<!DOCTYPE html>
 	<title>.</title>`)
 
-	accountable, err := ap.ResolveAccountable(context.Background(), b)
+	accountable, err := ap.ResolveAccountable(
+		context.Background(), io.NopCloser(bytes.NewReader(b)),
+	)
 	suite.True(gtserror.IsWrongType(err))
-	suite.EqualError(err, "ResolveAccountable: error unmarshalling bytes into json: invalid character '<' looking for beginning of value")
+	suite.EqualError(err, "ResolveAccountable: error decoding into json: invalid character '<' looking for beginning of value")
 	suite.Nil(accountable)
 }
 
@@ -64,7 +72,9 @@ func (suite *ResolveTestSuite) TestResolveNonAPJSONAsAccountable() {
   "pee pee":"poo poo"
 }`)
 
-	accountable, err := ap.ResolveAccountable(context.Background(), b)
+	accountable, err := ap.ResolveAccountable(
+		context.Background(), io.NopCloser(bytes.NewReader(b)),
+	)
 	suite.True(gtserror.IsWrongType(err))
 	suite.EqualError(err, "ResolveAccountable: error resolving json into ap vocab type: activity stream did not match any known types")
 	suite.Nil(accountable)
diff --git a/internal/ap/util.go b/internal/ap/util.go
index c810b7985..967a1659d 100644
--- a/internal/ap/util.go
+++ b/internal/ap/util.go
@@ -19,10 +19,39 @@ package ap
 
 import (
 	"net/url"
+	"sync"
 
 	"github.com/superseriousbusiness/activity/streams/vocab"
 )
 
+const mapmax = 256
+
+// mapPool is a memory pool
+// of maps for JSON decoding.
+var mapPool sync.Pool
+
+// getMap acquires a map from memory pool.
+func getMap() map[string]any {
+	v := mapPool.Get()
+	if v == nil {
+		// preallocate map of max-size.
+		m := make(map[string]any, mapmax)
+		v = m
+	}
+	return v.(map[string]any) //nolint
+}
+
+// putMap clears and places map back in pool.
+func putMap(m map[string]any) {
+	if len(m) > mapmax {
+		// drop maps beyond
+		// our maximum size.
+		return
+	}
+	clear(m)
+	mapPool.Put(m)
+}
+
 // _TypeOrIRI wraps a vocab.Type to implement TypeOrIRI.
 type _TypeOrIRI struct {
 	vocab.Type
diff --git a/internal/federation/authenticate.go b/internal/federation/authenticate.go
index 59281fa65..596233b19 100644
--- a/internal/federation/authenticate.go
+++ b/internal/federation/authenticate.go
@@ -23,6 +23,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
 	"net/http"
 	"net/url"
 	"time"
@@ -414,10 +415,19 @@ func (f *Federator) callForPubKey(
 
 	// The actual http call to the remote server is
 	// made right here by the Dereference function.
-	pubKeyBytes, err := trans.Dereference(ctx, pubKeyID)
+	rsp, err := trans.Dereference(ctx, pubKeyID)
+
 	if err == nil {
-		// No problem.
-		return pubKeyBytes, nil
+		// Read the response body data.
+		b, err := io.ReadAll(rsp.Body)
+		_ = rsp.Body.Close() // done
+
+		if err != nil {
+			err := gtserror.Newf("error reading pubkey: %w", err)
+			return nil, gtserror.NewErrorInternalError(err)
+		}
+
+		return b, nil
 	}
 
 	if gtserror.StatusCode(err) == http.StatusGone {
diff --git a/internal/federation/dereferencing/account.go b/internal/federation/dereferencing/account.go
index c3ad6be5e..10d15bca6 100644
--- a/internal/federation/dereferencing/account.go
+++ b/internal/federation/dereferencing/account.go
@@ -19,14 +19,12 @@ package dereferencing
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"io"
 	"net/url"
 	"time"
 
-	"github.com/superseriousbusiness/activity/streams"
-	"github.com/superseriousbusiness/activity/streams/vocab"
+	"github.com/superseriousbusiness/activity/pub"
 	"github.com/superseriousbusiness/gotosocial/internal/ap"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
@@ -499,16 +497,17 @@ func (d *Dereferencer) enrichAccount(
 
 		case err == nil && account.Domain != accDomain:
 			// After webfinger, we now have correct account domain from which we can do a final DB check.
-			alreadyAcct, err := d.state.DB.GetAccountByUsernameDomain(ctx, account.Username, accDomain)
+			alreadyAcc, err := d.state.DB.GetAccountByUsernameDomain(ctx, account.Username, accDomain)
 			if err != nil && !errors.Is(err, db.ErrNoEntries) {
-				return nil, nil, gtserror.Newf("db err looking for account again after webfinger: %w", err)
+				return nil, nil, gtserror.Newf("db error getting account after webfinger: %w", err)
 			}
 
-			if alreadyAcct != nil {
-				// We had this account stored under
-				// the discovered accountDomain.
+			if alreadyAcc != nil {
+				// We had this account stored
+				// under discovered accountDomain.
+				//
 				// Proceed with this account.
-				account = alreadyAcct
+				account = alreadyAcc
 			}
 
 			// Whether we had the account or not, we
@@ -537,8 +536,9 @@ func (d *Dereferencer) enrichAccount(
 			)
 		}
 
+		// Check URI scheme ahead of time for more useful errs.
 		if uri.Scheme != "http" && uri.Scheme != "https" {
-			err = errors.New("account URI scheme must be http or https")
+			err := errors.New("account URI scheme must be http or https")
 			return nil, nil, gtserror.Newf(
 				"invalid uri %q: %w",
 				account.URI, gtserror.SetUnretrievable(err),
@@ -567,20 +567,52 @@ func (d *Dereferencer) enrichAccount(
 		// We were not given any (partial) ActivityPub
 		// version of this account as a parameter.
 		// Dereference latest version of the account.
-		b, err := tsport.Dereference(ctx, uri)
+		rsp, err := tsport.Dereference(ctx, uri)
 		if err != nil {
 			err := gtserror.Newf("error dereferencing %s: %w", uri, err)
 			return nil, nil, gtserror.SetUnretrievable(err)
 		}
 
-		// Attempt to resolve ActivityPub acc from data.
-		apubAcc, err = ap.ResolveAccountable(ctx, b)
+		// Attempt to resolve ActivityPub acc from response.
+		apubAcc, err = ap.ResolveAccountable(ctx, rsp.Body)
+
+		// Tidy up now done.
+		_ = rsp.Body.Close()
+
 		if err != nil {
-			// ResolveAccountable will set Unretrievable/WrongType
+			// ResolveAccountable will set gtserror.WrongType
 			// on the returned error, so we don't need to do it here.
-			err = gtserror.Newf("error resolving accountable from data for account %s: %w", uri, err)
+			err = gtserror.Newf("error resolving accountable %s: %w", uri, err)
 			return nil, nil, err
 		}
+
+		// Check whether input URI and final returned URI
+		// have changed (i.e. we followed some redirects).
+		if finalURIStr := rsp.Request.URL.String(); //
+		finalURIStr != uri.String() {
+
+			// NOTE: this URI check + database call is performed
+			// AFTER reading and closing response body, for performance.
+			//
+			// Check whether we have this account stored under *final* URI.
+			alreadyAcc, err := d.state.DB.GetAccountByURI(ctx, finalURIStr)
+			if err != nil && !errors.Is(err, db.ErrNoEntries) {
+				return nil, nil, gtserror.Newf("db error getting account after redirects: %w", err)
+			}
+
+			if alreadyAcc != nil {
+				// We had this account stored
+				// under discovered final URI.
+				//
+				// Proceed with this account.
+				account = alreadyAcc
+			}
+
+			// Update the input URI to
+			// the final determined URI
+			// for later URI checks.
+			uri = rsp.Request.URL
+		}
 	}
 
 	/*
@@ -1014,76 +1046,33 @@ func (d *Dereferencer) dereferenceAccountFeatured(ctx context.Context, requestUs
 		return err
 	}
 
-	// Pre-fetch a transport for requesting username, used by later deref procedures.
-	tsport, err := d.transportController.NewTransportForUsername(ctx, requestUser)
-	if err != nil {
-		return gtserror.Newf("couldn't create transport: %w", err)
-	}
-
-	b, err := tsport.Dereference(ctx, uri)
+	collect, err := d.dereferenceCollection(ctx, requestUser, uri)
 	if err != nil {
 		return err
 	}
 
-	m := make(map[string]interface{})
-	if err := json.Unmarshal(b, &m); err != nil {
-		return gtserror.Newf("error unmarshalling bytes into json: %w", err)
-	}
-
-	t, err := streams.ToType(ctx, m)
-	if err != nil {
-		return gtserror.Newf("error resolving json into ap vocab type: %w", err)
-	}
-
-	if t.GetTypeName() != ap.ObjectOrderedCollection {
-		return gtserror.Newf("%s was not an OrderedCollection", uri)
-	}
-
-	collection, ok := t.(vocab.ActivityStreamsOrderedCollection)
-	if !ok {
-		return gtserror.New("couldn't coerce OrderedCollection")
-	}
-
-	items := collection.GetActivityStreamsOrderedItems()
-	if items == nil {
-		return gtserror.New("nil orderedItems")
-	}
-
 	// Get previous pinned statuses (we'll need these later).
 	wasPinned, err := d.state.DB.GetAccountPinnedStatuses(ctx, account.ID)
 	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		return gtserror.Newf("error getting account pinned statuses: %w", err)
 	}
 
-	statusURIs := make([]*url.URL, 0, items.Len())
-	for iter := items.Begin(); iter != items.End(); iter = iter.Next() {
-		var statusURI *url.URL
+	var statusURIs []*url.URL
 
-		switch {
-		case iter.IsActivityStreamsNote():
-			// We got a whole Note. Extract the URI.
-			if note := iter.GetActivityStreamsNote(); note != nil {
-				if id := note.GetJSONLDId(); id != nil {
-					statusURI = id.GetIRI()
-				}
-			}
-		case iter.IsActivityStreamsArticle():
-			// We got a whole Article. Extract the URI.
-			if article := iter.GetActivityStreamsArticle(); article != nil {
-				if id := article.GetJSONLDId(); id != nil {
-					statusURI = id.GetIRI()
-				}
-			}
-		default:
-			// Try to get just the URI.
-			statusURI = iter.GetIRI()
+	for {
+		// Get next collect item.
+		item := collect.NextItem()
+		if item == nil {
+			break
 		}
 
-		if statusURI == nil {
+		// Check for available IRI.
+		itemIRI, _ := pub.ToId(item)
+		if itemIRI == nil {
 			continue
 		}
 
-		if statusURI.Host != uri.Host {
+		if itemIRI.Host != uri.Host {
 			// If this status doesn't share a host with its featured
 			// collection URI, we shouldn't trust it. Just move on.
 			continue
@@ -1093,13 +1082,13 @@ func (d *Dereferencer) dereferenceAccountFeatured(ctx context.Context, requestUs
 		// We do this here so that even if we can't get
 		// the status in the next part for some reason,
 		// we still know it was *meant* to be pinned.
-		statusURIs = append(statusURIs, statusURI)
+		statusURIs = append(statusURIs, itemIRI)
 
 		// Search for status by URI. Note this may return an existing model
 		// we have stored with an error from attempted update, so check both.
-		status, _, _, err := d.getStatusByURI(ctx, requestUser, statusURI)
+		status, _, _, err := d.getStatusByURI(ctx, requestUser, itemIRI)
 		if err != nil {
-			log.Errorf(ctx, "error getting status from featured collection %s: %v", statusURI, err)
+			log.Errorf(ctx, "error getting status from featured collection %s: %v", itemIRI, err)
 
 			if status == nil {
 				// This is only unactionable
@@ -1108,20 +1097,23 @@ func (d *Dereferencer) dereferenceAccountFeatured(ctx context.Context, requestUs
 			}
 		}
 
-		// If the status was already pinned, we don't need to do anything.
+		// If the status was already pinned,
+		// we don't need to do anything.
 		if !status.PinnedAt.IsZero() {
 			continue
 		}
 
-		if status.AccountID != account.ID {
+		if status.AccountURI != account.URI {
 			// Someone's pinned a status that doesn't
 			// belong to them, this doesn't work for us.
 			continue
 		}
 
 		if status.BoostOfID != "" {
-			// Someone's pinned a boost. This also
-			// doesn't work for us.
+			// Someone's pinned a boost. This
+			// also doesn't work for us. (note
+			// we check using BoostOfID since
+			// BoostOfURI isn't *always* set).
 			continue
 		}
 
diff --git a/internal/federation/dereferencing/announce.go b/internal/federation/dereferencing/announce.go
index 8d082105b..02b1d5e5c 100644
--- a/internal/federation/dereferencing/announce.go
+++ b/internal/federation/dereferencing/announce.go
@@ -83,6 +83,10 @@ func (d *Dereferencer) EnrichAnnounce(
 		return nil, gtserror.Newf("error generating id: %w", err)
 	}
 
+	// Set boost_of_uri again in case the
+	// original URI was an indirect link.
+	boost.BoostOfURI = target.URI
+
 	// Populate remaining fields on
 	// the boost wrapper using target.
 	boost.Content = target.Content
@@ -101,10 +105,10 @@ func (d *Dereferencer) EnrichAnnounce(
 	boost.Replyable = target.Replyable
 	boost.Likeable = target.Likeable
 
-	// Store the boost wrapper status.
+	// Store the boost wrapper status in database.
 	switch err = d.state.DB.PutStatus(ctx, boost); {
 	case err == nil:
-		// All good baby.
+		// all groovy.
 
 	case errors.Is(err, db.ErrAlreadyExists):
 		uri := boost.URI
@@ -119,8 +123,7 @@ func (d *Dereferencer) EnrichAnnounce(
 			)
 		}
 
-	default:
-		// Proper database error.
+	default: // Proper database error.
 		return nil, gtserror.Newf("db error inserting status: %w", err)
 	}
 
diff --git a/internal/federation/dereferencing/collectionpage.go b/internal/federation/dereferencing/collection.go
index dc5c68273..07f56c952 100644
--- a/internal/federation/dereferencing/collectionpage.go
+++ b/internal/federation/dereferencing/collection.go
@@ -19,18 +19,16 @@ package dereferencing
 
 import (
 	"context"
-	"encoding/json"
 	"net/url"
 
-	"github.com/superseriousbusiness/activity/streams"
 	"github.com/superseriousbusiness/activity/streams/vocab"
 	"github.com/superseriousbusiness/gotosocial/internal/ap"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/log"
 )
 
-// dereferenceCollectionPage returns the activitystreams CollectionPage at the specified IRI, or an error if something goes wrong.
-func (d *Dereferencer) dereferenceCollectionPage(ctx context.Context, username string, pageIRI *url.URL) (ap.CollectionPageIterator, error) {
+// dereferenceCollectionPage returns the activitystreams Collection at the specified IRI, or an error if something goes wrong.
+func (d *Dereferencer) dereferenceCollection(ctx context.Context, username string, pageIRI *url.URL) (ap.CollectionIterator, error) {
 	if blocked, err := d.state.DB.IsDomainBlocked(ctx, pageIRI.Host); blocked || err != nil {
 		return nil, gtserror.Newf("domain %s is blocked", pageIRI.Host)
 	}
@@ -40,24 +38,46 @@ func (d *Dereferencer) dereferenceCollectionPage(ctx context.Context, username s
 		return nil, gtserror.Newf("error creating transport: %w", err)
 	}
 
-	b, err := transport.Dereference(ctx, pageIRI)
+	rsp, err := transport.Dereference(ctx, pageIRI)
 	if err != nil {
 		return nil, gtserror.Newf("error deferencing %s: %w", pageIRI.String(), err)
 	}
 
-	m := make(map[string]interface{})
-	if err := json.Unmarshal(b, &m); err != nil {
-		return nil, gtserror.Newf("error unmarshalling bytes into json: %w", err)
+	collect, err := ap.ResolveCollection(ctx, rsp.Body)
+
+	// Tidy up rsp body.
+	_ = rsp.Body.Close()
+
+	if err != nil {
+		return nil, gtserror.Newf("error resolving collection %s: %w", pageIRI.String(), err)
 	}
 
-	t, err := streams.ToType(ctx, m)
+	return collect, nil
+}
+
+// dereferenceCollectionPage returns the activitystreams CollectionPage at the specified IRI, or an error if something goes wrong.
+func (d *Dereferencer) dereferenceCollectionPage(ctx context.Context, username string, pageIRI *url.URL) (ap.CollectionPageIterator, error) {
+	if blocked, err := d.state.DB.IsDomainBlocked(ctx, pageIRI.Host); blocked || err != nil {
+		return nil, gtserror.Newf("domain %s is blocked", pageIRI.Host)
+	}
+
+	transport, err := d.transportController.NewTransportForUsername(ctx, username)
+	if err != nil {
+		return nil, gtserror.Newf("error creating transport: %w", err)
+	}
+
+	rsp, err := transport.Dereference(ctx, pageIRI)
 	if err != nil {
-		return nil, gtserror.Newf("error resolving json into ap vocab type: %w", err)
+		return nil, gtserror.Newf("error deferencing %s: %w", pageIRI.String(), err)
 	}
 
-	page, err := ap.ToCollectionPageIterator(t)
+	page, err := ap.ResolveCollectionPage(ctx, rsp.Body)
+
+	// Tidy up rsp body.
+	_ = rsp.Body.Close()
+
 	if err != nil {
-		return nil, gtserror.Newf("error resolving vocab type as page: %w", err)
+		return nil, gtserror.Newf("error resolving collection page %s: %w", pageIRI.String(), err)
 	}
 
 	return page, nil
diff --git a/internal/federation/dereferencing/status.go b/internal/federation/dereferencing/status.go
index e3f97553d..397d2aa28 100644
--- a/internal/federation/dereferencing/status.go
+++ b/internal/federation/dereferencing/status.go
@@ -393,16 +393,51 @@ func (d *Dereferencer) enrichStatus(
 
 	if apubStatus == nil {
 		// Dereference latest version of the status.
-		b, err := tsport.Dereference(ctx, uri)
+		rsp, err := tsport.Dereference(ctx, uri)
 		if err != nil {
 			err := gtserror.Newf("error dereferencing %s: %w", uri, err)
 			return nil, nil, gtserror.SetUnretrievable(err)
 		}
 
-		// Attempt to resolve ActivityPub status from data.
-		apubStatus, err = ap.ResolveStatusable(ctx, b)
+		// Attempt to resolve ActivityPub status from response.
+		apubStatus, err = ap.ResolveStatusable(ctx, rsp.Body)
+
+		// Tidy up now done.
+		_ = rsp.Body.Close()
+
 		if err != nil {
-			return nil, nil, gtserror.Newf("error resolving statusable from data for account %s: %w", uri, err)
+			// ResolveStatusable will set gtserror.WrongType
+			// on the returned error, so we don't need to do it here.
+			err = gtserror.Newf("error resolving statusable %s: %w", uri, err)
+			return nil, nil, err
+		}
+
+		// Check whether input URI and final returned URI
+		// have changed (i.e. we followed some redirects).
+		if finalURIStr := rsp.Request.URL.String(); //
+		finalURIStr != uri.String() {
+
+			// NOTE: this URI check + database call is performed
+			// AFTER reading and closing response body, for performance.
+			//
+			// Check whether we have this status stored under *final* URI.
+			alreadyStatus, err := d.state.DB.GetStatusByURI(ctx, finalURIStr)
+			if err != nil && !errors.Is(err, db.ErrNoEntries) {
+				return nil, nil, gtserror.Newf("db error getting status after redirects: %w", err)
+			}
+
+			if alreadyStatus != nil {
+				// We had this status stored
+				// under discovered final URI.
+				//
+				// Proceed with this status.
+				status = alreadyStatus
+			}
+
+			// Update the input URI to
+			// the final determined URI
+			// for later URI checks.
+			uri = rsp.Request.URL
 		}
 	}
 
diff --git a/internal/federation/dereferencing/thread.go b/internal/federation/dereferencing/thread.go
index 28f7ffa8a..e528581c9 100644
--- a/internal/federation/dereferencing/thread.go
+++ b/internal/federation/dereferencing/thread.go
@@ -33,7 +33,7 @@ import (
 
 // maxIter defines how many iterations of descendants or
 // ancesters we are willing to follow before returning error.
-const maxIter = 1000
+const maxIter = 512
 
 // dereferenceThread handles dereferencing status thread after
 // fetch. Passing off appropriate parts to be enqueued for async
@@ -98,16 +98,10 @@ func (d *Dereferencer) DereferenceStatusAncestors(ctx context.Context, username
 			return nil
 		}
 
+		// Apparent current parent URI to log fields.
 		l = l.WithField("parent", current.InReplyToURI)
 		l.Trace("following status ancestor")
 
-		// Parse status parent URI for later use.
-		uri, err := url.Parse(current.InReplyToURI)
-		if err != nil {
-			l.Warnf("invalid uri: %v", err)
-			return nil
-		}
-
 		// Check whether this parent has already been deref'd.
 		if _, ok := derefdStatuses[current.InReplyToURI]; ok {
 			l.Warn("self referencing status ancestor")
@@ -117,6 +111,13 @@ func (d *Dereferencer) DereferenceStatusAncestors(ctx context.Context, username
 		// Add this status's parent URI to map of deref'd.
 		derefdStatuses[current.InReplyToURI] = struct{}{}
 
+		// Parse status parent URI for later use.
+		uri, err := url.Parse(current.InReplyToURI)
+		if err != nil {
+			l.Warnf("invalid uri: %v", err)
+			return nil
+		}
+
 		// Fetch parent status by current's reply URI, this handles
 		// case of existing (updating if necessary) or a new status.
 		parent, _, _, err := d.getStatusByURI(ctx, username, uri)
@@ -129,6 +130,7 @@ func (d *Dereferencer) DereferenceStatusAncestors(ctx context.Context, username
 		// view the status (it's followers-only and
 		// we don't follow, for example).
 		case code == http.StatusNotFound:
+
 			// If this reply is followers-only or stricter,
 			// we can safely assume the status it replies
 			// to is also followers only or stricter.
@@ -153,31 +155,43 @@ func (d *Dereferencer) DereferenceStatusAncestors(ctx context.Context, username
 		// the now-gone parent.
 		case code == http.StatusGone:
 			l.Trace("status orphaned")
-			current.InReplyToID = ""
-			current.InReplyToURI = ""
-			current.InReplyToAccountID = ""
 			current.InReplyTo = nil
 			current.InReplyToAccount = nil
-			if err := d.state.DB.UpdateStatus(ctx,
+			return d.updateStatusParent(ctx,
 				current,
-				"in_reply_to_id",
-				"in_reply_to_uri",
-				"in_reply_to_account_id",
-			); err != nil {
-				return gtserror.Newf("db error updating status %s: %w", current.ID, err)
-			}
-			return nil
+				"", // status ID
+				"", // status URI
+				"", // account ID
+			)
 
 		// An error was returned for a status during
 		// an attempted NEW dereference, return here.
-		case err != nil && current.InReplyToID == "":
+		//
+		// NOTE: this will catch all cases of a nil
+		// parent, all cases below can safely assume
+		// a non-nil parent in their code logic.
+		case err != nil && parent == nil:
 			return gtserror.Newf("error dereferencing new %s: %w", current.InReplyToURI, err)
 
 		// An error was returned for an existing parent,
 		// we simply treat this as a temporary situation.
-		// (we fallback to using existing parent status).
 		case err != nil:
 			l.Errorf("error getting parent: %v", err)
+		}
+
+		// Start a new switch case
+		// as the following scenarios
+		// are possible with / without
+		// any returned error.
+		switch {
+
+		// The current status is using an indirect URL
+		// in order to reference the parent. This is just
+		// weird and broken... Leave the URI in place but
+		// don't link the statuses via database IDs as it
+		// could cause all sorts of unexpected situations.
+		case current.InReplyToURI != parent.URI:
+			l.Errorf("indirect in_reply_to_uri => %s", parent.URI)
 
 		// The ID has changed for currently stored parent ID
 		// (which may be empty, if new!) and fetched version.
@@ -185,17 +199,14 @@ func (d *Dereferencer) DereferenceStatusAncestors(ctx context.Context, username
 		// Update the current's inReplyTo fields to parent.
 		case current.InReplyToID != parent.ID:
 			l.Tracef("parent changed %s => %s", current.InReplyToID, parent.ID)
-			current.InReplyToAccountID = parent.AccountID
 			current.InReplyToAccount = parent.Account
-			current.InReplyToURI = parent.URI
-			current.InReplyToID = parent.ID
-			if err := d.state.DB.UpdateStatus(ctx,
+			if err := d.updateStatusParent(ctx,
 				current,
-				"in_reply_to_id",
-				"in_reply_to_uri",
-				"in_reply_to_account_id",
+				parent.ID,
+				parent.URI,
+				parent.AccountID,
 			); err != nil {
-				return gtserror.Newf("db error updating status %s: %w", current.ID, err)
+				return err
 			}
 		}
 
@@ -384,3 +395,26 @@ stackLoop:
 
 	return gtserror.Newf("reached %d descendant iterations for %q", maxIter, statusIRIStr)
 }
+
+// updateStatusParent updates the given status' parent
+// status URI, ID and account ID to given values in DB.
+func (d *Dereferencer) updateStatusParent(
+	ctx context.Context,
+	status *gtsmodel.Status,
+	parentStatusID string,
+	parentStatusURI string,
+	parentAccountID string,
+) error {
+	status.InReplyToAccountID = parentAccountID
+	status.InReplyToURI = parentStatusURI
+	status.InReplyToID = parentStatusID
+	if err := d.state.DB.UpdateStatus(ctx,
+		status,
+		"in_reply_to_id",
+		"in_reply_to_uri",
+		"in_reply_to_account_id",
+	); err != nil {
+		return gtserror.Newf("error updating status %s: %w", status.URI, err)
+	}
+	return nil
+}
diff --git a/internal/transport/controller.go b/internal/transport/controller.go
index 32ef6d7c2..81022596a 100644
--- a/internal/transport/controller.go
+++ b/internal/transport/controller.go
@@ -18,11 +18,15 @@
 package transport
 
 import (
+	"bytes"
 	"context"
 	"crypto/rsa"
 	"crypto/x509"
 	"encoding/json"
+	"errors"
 	"fmt"
+	"io"
+	"net/http"
 	"net/url"
 	"runtime"
 
@@ -31,6 +35,7 @@ import (
 	"github.com/superseriousbusiness/activity/pub"
 	"github.com/superseriousbusiness/gotosocial/internal/ap"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/federation/federatingdb"
 	"github.com/superseriousbusiness/gotosocial/internal/httpclient"
 	"github.com/superseriousbusiness/gotosocial/internal/state"
@@ -150,36 +155,73 @@ func (c *controller) NewTransportForUsername(ctx context.Context, username strin
 // account on this instance, without making any external api/http calls.
 //
 // It is passed to new transports, and should only be invoked when the iri.Host == this host.
-func (c *controller) dereferenceLocalFollowers(ctx context.Context, iri *url.URL) ([]byte, error) {
+func (c *controller) dereferenceLocalFollowers(ctx context.Context, iri *url.URL) (*http.Response, error) {
 	followers, err := c.fedDB.Followers(ctx, iri)
-	if err != nil {
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		return nil, err
 	}
 
+	if followers == nil {
+		// Return a generic 404 not found response.
+		rsp := craftResponse(iri, http.StatusNotFound)
+		return rsp, nil
+	}
+
 	i, err := ap.Serialize(followers)
 	if err != nil {
 		return nil, err
 	}
 
-	return json.Marshal(i)
+	b, err := json.Marshal(i)
+	if err != nil {
+		return nil, err
+	}
+
+	// Return a response with AS data as body.
+	rsp := craftResponse(iri, http.StatusOK)
+	rsp.Body = io.NopCloser(bytes.NewReader(b))
+	return rsp, nil
 }
 
 // dereferenceLocalUser is a shortcut to dereference followers an account on
 // this instance, without making any external api/http calls.
 //
 // It is passed to new transports, and should only be invoked when the iri.Host == this host.
-func (c *controller) dereferenceLocalUser(ctx context.Context, iri *url.URL) ([]byte, error) {
+func (c *controller) dereferenceLocalUser(ctx context.Context, iri *url.URL) (*http.Response, error) {
 	user, err := c.fedDB.Get(ctx, iri)
-	if err != nil {
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
 		return nil, err
 	}
 
+	if user == nil {
+		// Return a generic 404 not found response.
+		rsp := craftResponse(iri, http.StatusNotFound)
+		return rsp, nil
+	}
+
 	i, err := ap.Serialize(user)
 	if err != nil {
 		return nil, err
 	}
 
-	return json.Marshal(i)
+	b, err := json.Marshal(i)
+	if err != nil {
+		return nil, err
+	}
+
+	// Return a response with AS data as body.
+	rsp := craftResponse(iri, http.StatusOK)
+	rsp.Body = io.NopCloser(bytes.NewReader(b))
+	return rsp, nil
+}
+
+func craftResponse(url *url.URL, code int) *http.Response {
+	rsp := new(http.Response)
+	rsp.Request = new(http.Request)
+	rsp.Request.URL = url
+	rsp.Status = http.StatusText(code)
+	rsp.StatusCode = code
+	return rsp
 }
 
 // privkeyToPublicStr will create a string representation of RSA public key from private.
diff --git a/internal/transport/dereference.go b/internal/transport/dereference.go
index 3a33a81ad..efd3f0fbf 100644
--- a/internal/transport/dereference.go
+++ b/internal/transport/dereference.go
@@ -19,7 +19,6 @@ package transport
 
 import (
 	"context"
-	"io"
 	"net/http"
 	"net/url"
 
@@ -29,7 +28,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/uris"
 )
 
-func (t *transport) Dereference(ctx context.Context, iri *url.URL) ([]byte, error) {
+func (t *transport) Dereference(ctx context.Context, iri *url.URL) (*http.Response, error) {
 	// if the request is to us, we can shortcut for certain URIs rather than going through
 	// the normal request flow, thereby saving time and energy
 	if iri.Host == config.GetHost() {
@@ -62,18 +61,20 @@ func (t *transport) Dereference(ctx context.Context, iri *url.URL) ([]byte, erro
 	if err != nil {
 		return nil, err
 	}
-	defer rsp.Body.Close()
 
 	// Ensure a non-error status response.
 	if rsp.StatusCode != http.StatusOK {
-		return nil, gtserror.NewFromResponse(rsp)
+		err := gtserror.NewFromResponse(rsp)
+		_ = rsp.Body.Close() // done with body
+		return nil, err
 	}
 
 	// Ensure that the incoming request content-type is expected.
 	if ct := rsp.Header.Get("Content-Type"); !apiutil.ASContentType(ct) {
 		err := gtserror.Newf("non activity streams response: %s", ct)
+		_ = rsp.Body.Close() // done with body
 		return nil, gtserror.SetMalformed(err)
 	}
 
-	return io.ReadAll(rsp.Body)
+	return rsp, nil
 }
diff --git a/internal/transport/transport.go b/internal/transport/transport.go
index a2a9dc23c..99972fe25 100644
--- a/internal/transport/transport.go
+++ b/internal/transport/transport.go
@@ -65,7 +65,7 @@ type Transport interface {
 	GET(*http.Request) (*http.Response, error)
 
 	// Dereference fetches the ActivityStreams object located at this IRI with a GET request.
-	Dereference(ctx context.Context, iri *url.URL) ([]byte, error)
+	Dereference(ctx context.Context, iri *url.URL) (*http.Response, error)
 
 	// DereferenceMedia fetches the given media attachment IRI, returning the reader and filesize.
 	DereferenceMedia(ctx context.Context, iri *url.URL) (io.ReadCloser, int64, error)
diff --git a/internal/typeutils/astointernal_test.go b/internal/typeutils/astointernal_test.go
index fc8cd19a0..2ee2f9607 100644
--- a/internal/typeutils/astointernal_test.go
+++ b/internal/typeutils/astointernal_test.go
@@ -18,9 +18,11 @@
 package typeutils_test
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"testing"
 
 	"github.com/stretchr/testify/suite"
@@ -39,11 +41,11 @@ func (suite *ASToInternalTestSuite) jsonToType(in string) vocab.Type {
 	ctx := context.Background()
 	b := []byte(in)
 
-	if accountable, err := ap.ResolveAccountable(ctx, b); err == nil {
+	if accountable, err := ap.ResolveAccountable(ctx, io.NopCloser(bytes.NewReader(b))); err == nil {
 		return accountable
 	}
 
-	if statusable, err := ap.ResolveStatusable(ctx, b); err == nil {
+	if statusable, err := ap.ResolveStatusable(ctx, io.NopCloser(bytes.NewReader(b))); err == nil {
 		return statusable
 	}