Release v0.4.3

README.md

@@ -99,6 +99,12 @@ TMDB-backed metadata enrichment requires `TMDB_API_KEY` to be set in the environ
 
 ## Version History
 
+### 0.4.3
+
+- styled ASS subtitle sources with embedded font attachments are now detected explicitly, keep MKV output, preserve current source font attachments, and reject incompatible sidecar subtitle import
+- attachment descriptors are now treated as source-runtime data instead of pattern schema data, so pattern persistence skips them and source-vs-pattern validation ignores them
+- inspect differences no longer report planned changes for attachment filename/count drift while still showing attachment streams in the stream table
+
 ### 0.4.2
 
 - pattern details now show an inline `Show: <quality>` hint next to the quality field when the pattern itself has no stored quality but the selected show does

pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "ffx"
 description = "FFX recoding and metadata managing tool"
-version = "0.4.2"
+version = "0.4.3"
 license = {file = "LICENSE.md"}
 dependencies = [
   "requests",

src/ffx/cli.py

@@ -1139,6 +1139,7 @@ def convert(ctx,
     from ffx.tmdb_controller import TmdbController
     from ffx.track_codec import TrackCodec
     from ffx.track_disposition import TrackDisposition
+    from ffx.track_type import TrackType
     from ffx.video_encoder import VideoEncoder
 
     startTime = time.perf_counter()
@@ -1393,13 +1394,29 @@ def convert(ctx,
 
         from ffx.attachment_format import AttachmentFormat
 
-        if ([smd for smd in sourceMediaDescriptor.getSubtitleTracks()
-                    if smd.getCodec() == TrackCodec.ASS]
-                and [amd for amd in sourceMediaDescriptor.getAttachmentTracks()
-                    if amd.getAttachmentFormat() == AttachmentFormat.TTF]):
-            
+        styledAssDetector = getattr(
+            sourceMediaDescriptor,
+            "hasStyledAssSubtitlesWithFontAttachments",
+            None,
+        )
+        styledAssSourceDetected = (
+            bool(styledAssDetector())
+            if callable(styledAssDetector)
+            else False
+        )
+        if styledAssSourceDetected:
+            styledAssMessage = (
+                "Styled ASS subtitles with embedded font attachments detected; "
+                + "preserving source font attachments."
+            )
+            click.echo(styledAssMessage)
             targetFormat = ''
             targetExtension = 'mkv'
+            if context['import_subtitles']:
+                raise click.ClickException(
+                    "External subtitle import is incompatible with styled ASS "
+                    + "sources that carry embedded font attachments."
+                )
 
 
         #HINT: This is None if the filename did not match anything in database
@@ -1426,6 +1443,12 @@ def convert(ctx,
 
         else:
             targetMediaDescriptor = currentPattern.getMediaDescriptor(ctx.obj)
+            if styledAssSourceDetected:
+                targetMediaDescriptor = targetMediaDescriptor.withSourceAttachmentTracks(
+                    sourceMediaDescriptor,
+                    AttachmentFormat.TTF,
+                    context=ctx.obj,
+                )
             checkUniqueDispositions(context, targetMediaDescriptor)
             currentShowDescriptor = currentPattern.getShowDescriptor(ctx.obj)
 
@@ -1435,6 +1458,8 @@ def convert(ctx,
             targetTrackDescriptorList = targetMediaDescriptor.getTrackDescriptors()
 
             for ttd in targetTrackDescriptorList:
+                if ttd.getType() == TrackType.ATTACHMENT:
+                    continue
 
                 tti = ttd.getIndex()
                 ttsi = ttd.getSourceIndex()

src/ffx/constants.py

@@ -1,4 +1,4 @@
-VERSION='0.4.2'
+VERSION='0.4.3'
 DATABASE_VERSION = 3
 
 DEFAULT_QUALITY = 32

src/ffx/media_descriptor.py

@@ -329,6 +329,96 @@ class MediaDescriptor:
             if s.getType() == TrackType.ATTACHMENT
         ]
 
+    def hasStyledAssSubtitlesWithFontAttachments(self) -> bool:
+        return (
+            any(
+                trackDescriptor.getCodec() == TrackCodec.ASS
+                for trackDescriptor in self.getSubtitleTracks()
+            )
+            and any(
+                trackDescriptor.getAttachmentFormat() == AttachmentFormat.TTF
+                for trackDescriptor in self.getAttachmentTracks()
+            )
+        )
+
+    def withoutAttachmentTracks(
+        self,
+        attachmentFormat: AttachmentFormat | None = None,
+        context: dict | None = None,
+    ):
+        filteredTrackDescriptors = []
+        for trackDescriptor in self.__trackDescriptors:
+            if trackDescriptor.getType() == TrackType.ATTACHMENT and (
+                attachmentFormat is None
+                or trackDescriptor.getAttachmentFormat() == attachmentFormat
+            ):
+                continue
+            filteredTrackDescriptors.append(
+                trackDescriptor.clone(
+                    context=context if context is not None else self.__context
+                )
+            )
+
+        kwargs = {
+            MediaDescriptor.TAGS_KEY: dict(self.__mediaTags),
+            MediaDescriptor.TRACK_DESCRIPTOR_LIST_KEY: filteredTrackDescriptors,
+        }
+        if context is not None:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = context
+        elif self.__context:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = self.__context
+
+        filteredMediaDescriptor = MediaDescriptor(**kwargs)
+        filteredMediaDescriptor.reindexSubIndices()
+        return filteredMediaDescriptor
+
+    def withoutAttachmentsForComparison(self):
+        return self.withoutAttachmentTracks(context=self.__context)
+
+    def withSourceAttachmentTracks(
+        self,
+        sourceMediaDescriptor: Self,
+        attachmentFormat: AttachmentFormat | None = None,
+        context: dict | None = None,
+    ):
+        trackDescriptors = []
+        for trackDescriptor in self.__trackDescriptors:
+            if trackDescriptor.getType() == TrackType.ATTACHMENT and (
+                attachmentFormat is None
+                or trackDescriptor.getAttachmentFormat() == attachmentFormat
+            ):
+                continue
+            trackDescriptors.append(
+                trackDescriptor.clone(
+                    context=context if context is not None else self.__context
+                )
+            )
+
+        for sourceTrackDescriptor in sourceMediaDescriptor.getAttachmentTracks():
+            if (
+                attachmentFormat is not None
+                and sourceTrackDescriptor.getAttachmentFormat() != attachmentFormat
+            ):
+                continue
+            attachmentClone = sourceTrackDescriptor.clone(
+                context=context if context is not None else self.__context
+            )
+            attachmentClone.setIndex(len(trackDescriptors))
+            trackDescriptors.append(attachmentClone)
+
+        kwargs = {
+            MediaDescriptor.TAGS_KEY: dict(self.__mediaTags),
+            MediaDescriptor.TRACK_DESCRIPTOR_LIST_KEY: trackDescriptors,
+        }
+        if context is not None:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = context
+        elif self.__context:
+            kwargs[MediaDescriptor.CONTEXT_KEY] = self.__context
+
+        mergedMediaDescriptor = MediaDescriptor(**kwargs)
+        mergedMediaDescriptor.reindexSubIndices()
+        return mergedMediaDescriptor
+
 
     def getImportFileTokens(self, use_sub_index: bool = True):
         """Generate ffmpeg import options for external stream files"""

src/ffx/media_descriptor_change_set.py

@@ -56,8 +56,24 @@ class MediaDescriptorChangeSet():
                                     and 'ignore' in metadataConfiguration['streams'].keys() else [])
 
 
-        self.__targetTrackDescriptors = targetMediaDescriptor.getTrackDescriptors() if targetMediaDescriptor is not None else []
-        self.__sourceTrackDescriptors = sourceMediaDescriptor.getTrackDescriptors() if sourceMediaDescriptor is not None else []
+        self.__targetTrackDescriptors = (
+            [
+                trackDescriptor
+                for trackDescriptor in targetMediaDescriptor.getTrackDescriptors()
+                if trackDescriptor.getType() != TrackType.ATTACHMENT
+            ]
+            if targetMediaDescriptor is not None
+            else []
+        )
+        self.__sourceTrackDescriptors = (
+            [
+                trackDescriptor
+                for trackDescriptor in sourceMediaDescriptor.getTrackDescriptors()
+                if trackDescriptor.getType() != TrackType.ATTACHMENT
+            ]
+            if sourceMediaDescriptor is not None
+            else []
+        )
         self.__targetTrackDescriptorsByIndex = {
             trackDescriptor.getIndex(): trackDescriptor
             for trackDescriptor in self.__targetTrackDescriptors

src/ffx/media_workflow_screen_base.py

@@ -166,10 +166,9 @@ class MediaWorkflowScreenBase(Screen):
             self._baselineMediaDescriptor = probedMediaDescriptor
             self._sourceMediaDescriptor = probedMediaDescriptor
             self._currentPattern = self._mediaFileProperties.getPattern()
-            self._targetMediaDescriptor = (
-                self._currentPattern.getMediaDescriptor(self.context)
-                if self._currentPattern is not None
-                else None
+            self._targetMediaDescriptor = self._resolve_target_media_descriptor(
+                self._currentPattern,
+                self._sourceMediaDescriptor,
             )
 
         self.rebuildChangeSet()
@@ -205,6 +204,25 @@ class MediaWorkflowScreenBase(Screen):
     def getTrackEditSourceDescriptor(self) -> TrackDescriptor | None:
         return self.getSelectedTrackDescriptor()
 
+    def _resolve_target_media_descriptor(self, currentPattern, sourceMediaDescriptor):
+        if currentPattern is None:
+            return None
+
+        targetMediaDescriptor = currentPattern.getMediaDescriptor(self.context)
+        styledAssDetector = getattr(
+            sourceMediaDescriptor,
+            "hasStyledAssSubtitlesWithFontAttachments",
+            None,
+        )
+        if callable(styledAssDetector) and styledAssDetector():
+            targetMediaDescriptor = targetMediaDescriptor.withSourceAttachmentTracks(
+                sourceMediaDescriptor,
+                AttachmentFormat.TTF,
+                context=self.context,
+            )
+
+        return targetMediaDescriptor
+
     def updateMediaTags(self):
         displayedMediaDescriptor = self.getDisplayedMediaDescriptor()
         self._sourceMediaTagRowData = populate_tag_table(

src/ffx/model/pattern.py

@@ -7,6 +7,7 @@ from .show import Base, Show
 
 from ffx.media_descriptor import MediaDescriptor
 from ffx.show_descriptor import ShowDescriptor
+from ffx.track_type import TrackType
 
 
 class Pattern(Base):
@@ -76,6 +77,8 @@ class Pattern(Base):
         subIndexCounter = {}
         for track in self.tracks:
             trackType = track.getType()
+            if trackType == TrackType.ATTACHMENT:
+                continue
             if not trackType in subIndexCounter.keys():
                 subIndexCounter[trackType] = 0
             kwargs[MediaDescriptor.TRACK_DESCRIPTOR_LIST_KEY].append(track.getDescriptor(context, subIndex = subIndexCounter[trackType]))

src/ffx/pattern_controller.py

@@ -8,6 +8,7 @@ from ffx.model.track import Track
 from ffx.model.track_tag import TrackTag
 from ffx.track_descriptor import TrackDescriptor
 from ffx.track_disposition import TrackDisposition
+from ffx.track_type import TrackType
 
 
 class DuplicatePatternMatchError(click.ClickException):
@@ -86,12 +87,16 @@ class PatternController:
             )
 
         normalized_descriptors = []
+        filtered_attachments = False
         for trackDescriptor in trackDescriptors:
             if type(trackDescriptor) is not TrackDescriptor:
                 raise TypeError(
                     "PatternController: All track descriptors are required to be of type TrackDescriptor"
                 )
-            normalized_descriptors.append(trackDescriptor)
+            if trackDescriptor.getType() == TrackType.ATTACHMENT:
+                filtered_attachments = True
+                continue
+            normalized_descriptors.append(trackDescriptor.clone())
 
         if not normalized_descriptors:
             raise InvalidPatternSchemaError(
@@ -102,6 +107,10 @@ class PatternController:
             normalized_descriptors, key=lambda descriptor: descriptor.getIndex()
         )
 
+        if filtered_attachments:
+            for index, descriptor in enumerate(normalized_descriptors):
+                descriptor.setIndex(index)
+
         index_set = {descriptor.getIndex() for descriptor in normalized_descriptors}
         expected_indexes = set(range(len(normalized_descriptors)))
         if index_set != expected_indexes:
@@ -170,7 +179,7 @@ class PatternController:
             pattern.tracks.append(self._build_track_row(trackDescriptor))
 
     def _validate_persisted_pattern(self, pattern: Pattern):
-        if not pattern.tracks:
+        if not any(track.getType() != TrackType.ATTACHMENT for track in pattern.tracks):
             raise InvalidPatternSchemaError(
                 f"Pattern #{pattern.getId()} ({pattern.getPattern()!r}) is invalid because it has no tracks."
             )

src/ffx/track_controller.py

@@ -35,6 +35,8 @@ class TrackController():
 
 
     def addTrack(self, trackDescriptor : TrackDescriptor, patternId = None):
+        if trackDescriptor.getType() == TrackType.ATTACHMENT:
+            return False
 
         # option to override pattern id in case track descriptor has not set it
         patId = int(trackDescriptor.getPatternId() if patternId is None else patternId)
@@ -72,6 +74,8 @@ class TrackController():
 
         if type(trackDescriptor) is not TrackDescriptor:
             raise TypeError('TrackController.updateTrack(): Argument trackDescriptor is required to be of type TrackDescriptor')
+        if trackDescriptor.getType() == TrackType.ATTACHMENT:
+            return False
 
         try:
             s = self.Session()

tests/integration/subtrack_mapping/test_cli_bundle.py

@@ -18,6 +18,7 @@ from tests.support.ffx_bundle import (
     write_vtt,
 )
 
+from ffx.attachment_format import AttachmentFormat
 from ffx.track_type import TrackType
 
 try:
@@ -280,6 +281,72 @@ class SubtrackMappingBundleTests(unittest.TestCase):
         self.assertIn("non-existent source track #99", error_output)
         self.assertFalse(expected_output_path(self.workdir, source_filename).exists())
 
+    def test_styled_ass_source_preserves_current_font_attachments_when_pattern_count_differs(self):
+        source_filename = "styled_ass_s01e01.mkv"
+        source_path = create_source_fixture(
+            self.workdir,
+            source_filename,
+            [
+                SourceTrackSpec(TrackType.VIDEO, identity="video-0"),
+                SourceTrackSpec(TrackType.AUDIO, identity="audio-1", language="eng"),
+                SourceTrackSpec(
+                    TrackType.SUBTITLE,
+                    identity="subtitle-2",
+                    language="eng",
+                    subtitle_lines=("styled subtitle payload",),
+                ),
+                SourceTrackSpec(TrackType.ATTACHMENT, attachment_name="current.ttf"),
+            ],
+            subtitle_encoder="ass",
+        )
+
+        prepare_pattern_database(
+            self.database_path,
+            r"^styled_ass_(s[0-9]+e[0-9]+)\.mkv$",
+            [
+                PatternTrackSpec(index=0, source_index=0, track_type=TrackType.VIDEO),
+                PatternTrackSpec(index=1, source_index=1, track_type=TrackType.AUDIO),
+                PatternTrackSpec(index=2, source_index=2, track_type=TrackType.SUBTITLE),
+                PatternTrackSpec(
+                    index=3,
+                    source_index=3,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                ),
+                PatternTrackSpec(
+                    index=4,
+                    source_index=4,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                ),
+            ],
+        )
+
+        completed = run_ffx_convert(
+            self.workdir,
+            self.home_dir,
+            self.database_path,
+            "--video-encoder",
+            "copy",
+            "--no-tmdb",
+            "--no-prompt",
+            "--no-signature",
+            str(source_path),
+        )
+        self.assertCompleted(completed)
+        self.assertIn("Styled ASS subtitles", completed.stdout)
+
+        output_path = expected_output_path(self.workdir, source_filename)
+        streams = ffprobe_json(output_path)["streams"]
+
+        self.assertEqual(
+            [stream["codec_type"] for stream in streams],
+            ["video", "audio", "subtitle", "attachment"],
+        )
+        self.assertEqual(streams[2]["codec_name"], "ass")
+        self.assertEqual(streams[3]["codec_name"], "ttf")
+        self.assertEqual(get_tag(streams[3], "filename"), "current.ttf")
+
     def test_external_subtitle_file_replaces_payload_and_overrides_metadata(self):
         source_filename = "substitute_s01e01.mkv"
         self.write_config(

tests/support/ffx_bundle.py

@@ -18,6 +18,7 @@ if str(SRC_ROOT) not in sys.path:
     sys.path.insert(0, str(SRC_ROOT))
 
 
+from ffx.attachment_format import AttachmentFormat
 from ffx.audio_layout import AudioLayout
 from ffx.database import databaseContext
 from ffx.pattern_controller import PatternController
@@ -56,6 +57,7 @@ class PatternTrackSpec:
     tags: Mapping[str, str] = field(default_factory=dict)
     dispositions: tuple[TrackDisposition, ...] = ()
     audio_layout: AudioLayout = AudioLayout.LAYOUT_STEREO
+    attachment_format: AttachmentFormat = AttachmentFormat.UNKNOWN
 
 
 def make_logger(name: str) -> logging.Logger:
@@ -299,6 +301,8 @@ def prepare_pattern_database(database_path: Path, filename_pattern: str, track_s
             }
             if track.track_type == TrackType.AUDIO:
                 kwargs[TrackDescriptor.AUDIO_LAYOUT_KEY] = track.audio_layout
+            if track.track_type == TrackType.ATTACHMENT:
+                kwargs[TrackDescriptor.ATTACHMENT_FORMAT_KEY] = track.attachment_format
             track_descriptors.append(TrackDescriptor(**kwargs))
 
         pattern_id = PatternController(context).savePatternSchema(

tests/unit/test_media_descriptor_change_set.py

@@ -13,6 +13,7 @@ if str(SRC_ROOT) not in sys.path:
 
 from ffx.media_descriptor import MediaDescriptor  # noqa: E402
 from ffx.media_descriptor_change_set import MediaDescriptorChangeSet  # noqa: E402
+from ffx.attachment_format import AttachmentFormat  # noqa: E402
 from ffx.track_descriptor import TrackDescriptor  # noqa: E402
 from ffx.track_type import TrackType  # noqa: E402
 from ffx.i18n import set_current_language  # noqa: E402
@@ -436,6 +437,47 @@ class MediaDescriptorChangeSetTests(unittest.TestCase):
         self.assertNotIn("creation_time=", metadata_tokens)
         self.assertNotIn("BPS=", metadata_tokens)
 
+    def test_attachment_tracks_are_ignored_for_pattern_comparison(self):
+        context = {
+            "logger": get_ffx_logger(),
+            "config": StaticConfig({}),
+        }
+
+        source_track = TrackDescriptor(
+            index=0,
+            source_index=0,
+            sub_index=0,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "current.ttf", "mimetype": "font/ttf"},
+        )
+        target_track = TrackDescriptor(
+            index=0,
+            source_index=0,
+            sub_index=0,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "stored.ttf", "mimetype": "font/ttf"},
+        )
+        stale_target_track = TrackDescriptor(
+            index=1,
+            source_index=1,
+            sub_index=1,
+            track_type=TrackType.ATTACHMENT,
+            attachment_format=AttachmentFormat.TTF,
+            tags={"filename": "missing.ttf", "mimetype": "font/ttf"},
+        )
+
+        change_set = MediaDescriptorChangeSet(
+            context,
+            MediaDescriptor(track_descriptors=[target_track, stale_target_track]),
+            MediaDescriptor(track_descriptors=[source_track]),
+        )
+
+        self.assertEqual({}, change_set.getChangeSetObj())
+        self.assertEqual([], change_set.generateMetadataTokens())
+        self.assertEqual([], change_set.generateDispositionTokens())
+
     def test_normalization_can_be_disabled_per_context(self):
         context = {
             "logger": get_ffx_logger(),

tests/unit/test_pattern_management.py

@@ -193,6 +193,36 @@ class PatternManagementTests(unittest.TestCase):
 
         self.assertIn("at least one track", str(caught.exception))
 
+    def test_save_pattern_schema_does_not_persist_attachment_tracks(self):
+        pattern_id = self.save_pattern(
+            1,
+            r"^noattachments_(s[0-9]+e[0-9]+)\.mkv$",
+            tracks=[
+                make_track_descriptor(0, track_type=TrackType.VIDEO),
+                make_track_descriptor(1, track_type=TrackType.ATTACHMENT),
+            ],
+        )
+
+        Session = self.context["database"]["session"]
+        session = Session()
+        try:
+            tracks = session.query(Pattern).filter(Pattern.id == pattern_id).first().tracks
+            self.assertEqual(1, len(tracks))
+            self.assertEqual(TrackType.VIDEO, tracks[0].getType())
+        finally:
+            session.close()
+
+    def test_track_controller_does_not_add_attachment_tracks_to_patterns(self):
+        pattern_id = self.save_pattern(1, r"^skipadd_(s[0-9]+e[0-9]+)\.mkv$")
+
+        added = self.track_controller.addTrack(
+            make_track_descriptor(1, track_type=TrackType.ATTACHMENT),
+            patternId=pattern_id,
+        )
+
+        self.assertFalse(added)
+        self.assertEqual(1, len(self.track_controller.findTracks(pattern_id)))
+
     def test_match_filename_rejects_existing_trackless_pattern_rows(self):
         self.insert_trackless_pattern_row(1, r"^invalid_(s[0-9]+e[0-9]+)\.mkv$")
 

tests/unit/test_tag_table_screen_state.py

@@ -15,12 +15,13 @@ if str(SRC_ROOT) not in sys.path:
 
 from ffx.audio_layout import AudioLayout  # noqa: E402
 from ffx.attachment_format import AttachmentFormat  # noqa: E402
-from ffx.helper import DIFF_ADDED_KEY  # noqa: E402
+from ffx.helper import DIFF_ADDED_KEY, DIFF_REMOVED_KEY  # noqa: E402
 from ffx.iso_language import IsoLanguage  # noqa: E402
 from ffx.logging_utils import get_ffx_logger  # noqa: E402
 from ffx.inspect_details_screen import InspectDetailsScreen  # noqa: E402
 from ffx.i18n import set_current_language  # noqa: E402
 from ffx.media_descriptor import MediaDescriptor  # noqa: E402
+from ffx.media_descriptor_change_set import MediaDescriptorChangeSet  # noqa: E402
 from ffx.media_edit_screen import MediaEditScreen  # noqa: E402
 from ffx.pattern_details_screen import PatternDetailsScreen  # noqa: E402
 from ffx.show_descriptor import ShowDescriptor  # noqa: E402
@@ -822,6 +823,89 @@ class TagTableScreenStateTests(unittest.TestCase):
         self.assertEqual("unknown", row[3])
         self.assertEqual(" ", row[5])
 
+    def test_inspect_details_screen_uses_source_font_attachments_for_styled_ass(self):
+        class _Config:
+            def getData(self):
+                return {}
+
+        class _Pattern:
+            def __init__(self, media_descriptor):
+                self._media_descriptor = media_descriptor
+
+            def getMediaDescriptor(self, _context):
+                return self._media_descriptor
+
+        source_descriptor = MediaDescriptor(
+            track_descriptors=[
+                TrackDescriptor(
+                    index=0,
+                    source_index=0,
+                    sub_index=0,
+                    track_type=TrackType.SUBTITLE,
+                    codec_name=TrackCodec.ASS,
+                    tags={"title": "Styled Subtitle"},
+                ),
+                TrackDescriptor(
+                    index=1,
+                    source_index=1,
+                    sub_index=0,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                    tags={"filename": "current.ttf", "mimetype": "font/ttf"},
+                ),
+            ]
+        )
+        pattern_descriptor = MediaDescriptor(
+            track_descriptors=[
+                TrackDescriptor(
+                    index=0,
+                    source_index=0,
+                    sub_index=0,
+                    track_type=TrackType.SUBTITLE,
+                    codec_name=TrackCodec.ASS,
+                    tags={"title": "Styled Subtitle"},
+                ),
+                TrackDescriptor(
+                    index=1,
+                    source_index=1,
+                    sub_index=0,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                    tags={"filename": "old.ttf", "mimetype": "font/ttf"},
+                ),
+                TrackDescriptor(
+                    index=2,
+                    source_index=2,
+                    sub_index=1,
+                    track_type=TrackType.ATTACHMENT,
+                    attachment_format=AttachmentFormat.TTF,
+                    tags={"filename": "missing.ttf", "mimetype": "font/ttf"},
+                ),
+            ]
+        )
+
+        screen = object.__new__(InspectDetailsScreen)
+        screen.context = {"logger": get_ffx_logger(), "config": _Config()}
+
+        resolved_descriptor = screen._resolve_target_media_descriptor(
+            _Pattern(pattern_descriptor),
+            source_descriptor,
+        )
+        attachment_tracks = resolved_descriptor.getAttachmentTracks()
+
+        self.assertEqual(1, len(attachment_tracks))
+        self.assertEqual({"filename": "current.ttf", "mimetype": "font/ttf"}, attachment_tracks[0].getTags())
+
+        change_set = MediaDescriptorChangeSet(
+            screen.context,
+            resolved_descriptor,
+            source_descriptor,
+        ).getChangeSetObj()
+        self.assertNotIn(
+            1,
+            change_set.get("tracks", {}).get(DIFF_REMOVED_KEY, {}),
+        )
+
     def test_inspect_details_screen_maps_target_selection_back_to_source_track(self):
         source_track = TrackDescriptor(
             index=3,