fix(appearance): sync close Android theme wallpaper fallback

Public projection of telesrv 2c8b7cb4c20692d00017bd84f68dd11d7915ec33 with neutral appearance seed naming. Covers gramsrv#29.

internal/compat/tdesktop/appearance_seed.go

@@ -50,9 +50,56 @@ func LookupWallPaper(input tg.InputWallPaperClass) (tg.WallPaperClass, bool) {
 			}
 		}
 	}
+	// DrKLO normally installs a default theme with the nested wallpaper slug
+	// stored on ThemeAccent. During accent restoration it can instead fall back
+	// to ThemeInfo.slug, which is the slug of the exact Theme advertised by
+	// account.getThemes. Accept that server-issued alias only when every setting
+	// of the matched theme points at one unambiguous file wallpaper.
+	if in, ok := input.(*tg.InputWallPaperSlug); ok {
+		if wallpaper, ok := lookupChatThemeWallpaperAlias(catalog.ChatThemes, in.Slug); ok {
+			return DefaultWallPaper(wallpaper), true
+		}
+	}
 	return nil, false
 }
 
+func lookupChatThemeWallpaperAlias(themes []appearance.ChatTheme, slug string) (appearance.Wallpaper, bool) {
+	if slug == "" {
+		return appearance.Wallpaper{}, false
+	}
+	var resolved appearance.Wallpaper
+	found := false
+	for _, theme := range themes {
+		if theme.Slug != slug || len(theme.Settings) == 0 {
+			continue
+		}
+		var themeWallpaper appearance.Wallpaper
+		for i, settings := range theme.Settings {
+			wallpaper := settings.Wallpaper
+			if wallpaper.Slug == "" || wallpaper.ID == 0 {
+				return appearance.Wallpaper{}, false
+			}
+			if i == 0 {
+				themeWallpaper = wallpaper
+				continue
+			}
+			if !sameWallpaperIdentity(themeWallpaper, wallpaper) {
+				return appearance.Wallpaper{}, false
+			}
+		}
+		if found && !sameWallpaperIdentity(resolved, themeWallpaper) {
+			return appearance.Wallpaper{}, false
+		}
+		resolved = themeWallpaper
+		found = true
+	}
+	return resolved, found
+}
+
+func sameWallpaperIdentity(a, b appearance.Wallpaper) bool {
+	return a.ID == b.ID && a.AccessHash == b.AccessHash && a.Slug == b.Slug
+}
+
 // LookupWallPapers resolves multiple wallpapers from the Default seed catalog.
 func LookupWallPapers(inputs []tg.InputWallPaperClass) ([]tg.WallPaperClass, bool) {
 	out := make([]tg.WallPaperClass, 0, len(inputs))

internal/compat/tdesktop/startup_stubs.go

@@ -57,7 +57,7 @@ func GlobalPrivacySettings() *tg.GlobalPrivacySettings {
 	return &tg.GlobalPrivacySettings{}
 }
 
-const chatThemesHash int64 = 2026062501
+const chatThemesHash int64 = 2026080101
 const uniqueGiftChatThemesHash int64 = 2026061201
 const wallPapersHash int64 = 2026062502
 const peerColorsHash = 2026061202
@@ -233,9 +233,14 @@ func WallPapers(hash int64) tg.AccountWallPapersClass {
 }
 
 // chatThemeBaseThemes enumerates the base themes every emoji chat theme ships
-// settings for. The client matches a chat theme's settings to whichever base
+// settings for. The order is part of the DrKLO client contract: the basic Chat
-// theme the user currently runs, and DrKLO's theme picker only surfaces a chat
+// Settings picker selects index 0 for day and index 2 for night, matching its
-// theme whose settings cover at least four base themes
+// built-in Blue, Day, Night, Dark Blue ordering. Arctic is an additional base
+// and therefore follows those four stable slots.
+//
+// The client matches a chat theme's settings to whichever base theme the user
+// currently runs, and DrKLO's theme picker only surfaces a chat theme whose
+// settings cover at least four base themes
 // (MediaDataController.generateEmojiPreviewThemes drops anything whose
 // items.size() < 4, one item per ThemeSettings). dark selects the bubble/accent
 // palette used for that base theme.
@@ -245,9 +250,9 @@ var chatThemeBaseThemes = []struct {
 }{
 	{func() tg.BaseThemeClass { return &tg.BaseThemeClassic{} }, false},
 	{func() tg.BaseThemeClass { return &tg.BaseThemeDay{} }, false},
-	{func() tg.BaseThemeClass { return &tg.BaseThemeArctic{} }, false},
-	{func() tg.BaseThemeClass { return &tg.BaseThemeTinted{} }, true},
 	{func() tg.BaseThemeClass { return &tg.BaseThemeNight{} }, true},
+	{func() tg.BaseThemeClass { return &tg.BaseThemeTinted{} }, true},
+	{func() tg.BaseThemeClass { return &tg.BaseThemeArctic{} }, false},
 }
 
 func AutoDownloadSettings() *tg.AccountAutoDownloadSettings {

internal/compat/tdesktop/startup_stubs_test.go

@@ -5,6 +5,8 @@ import (
 	"testing"
 
 	"github.com/iamxvbaba/td/tg"
+
+	"telesrv/internal/seed/appearance"
 )
 
 func TestNotifySettingsDefaultIsAudible(t *testing.T) {
@@ -216,6 +218,39 @@ func TestDefaultThemesAreDefaultFlaggedForPicker(t *testing.T) {
 	}
 }
 
+func TestDefaultThemeSettingsFollowDrKLOPickerIndices(t *testing.T) {
+	for _, theme := range DefaultThemeList() {
+		settings, ok := theme.GetSettings()
+		if !ok || len(settings) < 5 {
+			t.Fatalf("theme %d settings len=%d ok=%v, want five stable base slots", theme.ID, len(settings), ok)
+		}
+		if _, ok := settings[0].BaseTheme.(*tg.BaseThemeClassic); !ok {
+			t.Fatalf("theme %d settings[0] base = %T, want classic", theme.ID, settings[0].BaseTheme)
+		}
+		if _, ok := settings[1].BaseTheme.(*tg.BaseThemeDay); !ok {
+			t.Fatalf("theme %d settings[1] base = %T, want day", theme.ID, settings[1].BaseTheme)
+		}
+		if _, ok := settings[2].BaseTheme.(*tg.BaseThemeNight); !ok {
+			t.Fatalf("theme %d settings[2] base = %T, want night", theme.ID, settings[2].BaseTheme)
+		}
+		if _, ok := settings[3].BaseTheme.(*tg.BaseThemeTinted); !ok {
+			t.Fatalf("theme %d settings[3] base = %T, want tinted", theme.ID, settings[3].BaseTheme)
+		}
+		if _, ok := settings[4].BaseTheme.(*tg.BaseThemeArctic); !ok {
+			t.Fatalf("theme %d settings[4] base = %T, want arctic", theme.ID, settings[4].BaseTheme)
+		}
+		wallpaperClass, ok := settings[2].GetWallpaper()
+		wallpaper, fileWallpaper := wallpaperClass.(*tg.WallPaper)
+		if !ok || !fileWallpaper || !wallpaper.GetDark() {
+			t.Fatalf("theme %d night slot wallpaper = %#v ok=%v, want dark file wallpaper", theme.ID, wallpaperClass, ok)
+		}
+	}
+
+	if _, ok := ChatThemes(2026062501).(*tg.AccountThemesNotModified); ok {
+		t.Fatal("pre-fix chat theme hash was not invalidated after settings reorder")
+	}
+}
+
 func TestLookupDefaultThemeValidatesIdentity(t *testing.T) {
 	themes := DefaultThemeList()
 	if len(themes) == 0 {
@@ -366,12 +401,38 @@ func TestDefaultThemeWallpaperReferencesResolve(t *testing.T) {
 				t.Fatalf("theme %d settings[%d] wallpaper slug lookup = %#v", theme.ID, i, bySlug)
 			}
 		}
+		byThemeSlug, ok := LookupWallPaper(&tg.InputWallPaperSlug{Slug: theme.Slug})
+		if !ok {
+			t.Fatalf("theme %d fallback wallpaper alias %q was not resolvable", theme.ID, theme.Slug)
+		}
+		aliasWallpaper, ok := byThemeSlug.(*tg.WallPaper)
+		firstWallpaperClass, firstOK := settings[0].GetWallpaper()
+		firstWallpaper, firstFile := firstWallpaperClass.(*tg.WallPaper)
+		if !ok || !firstOK || !firstFile || aliasWallpaper.ID != firstWallpaper.ID || aliasWallpaper.Slug != firstWallpaper.Slug {
+			t.Fatalf("theme %d fallback alias = %#v, want settings[0] wallpaper %#v", theme.ID, byThemeSlug, firstWallpaperClass)
+		}
 	}
 	if checked == 0 {
 		t.Fatal("default themes exposed no file wallpapers")
 	}
 }
 
+func TestChatThemeWallpaperAliasRejectsAmbiguousSettings(t *testing.T) {
+	themes := []appearance.ChatTheme{{
+		Slug: "theme-alias",
+		Settings: []appearance.ThemeSettings{
+			{Wallpaper: appearance.Wallpaper{ID: 1, AccessHash: 11, Slug: "wallpaper-one"}},
+			{Wallpaper: appearance.Wallpaper{ID: 2, AccessHash: 22, Slug: "wallpaper-two"}},
+		},
+	}}
+	if _, ok := lookupChatThemeWallpaperAlias(themes, "theme-alias"); ok {
+		t.Fatal("ambiguous theme wallpaper alias was accepted")
+	}
+	if _, ok := lookupChatThemeWallpaperAlias(themes, "unknown"); ok {
+		t.Fatal("unknown theme wallpaper alias was accepted")
+	}
+}
+
 func TestStarsRevenueStatsIsZeroBalanceCompatStub(t *testing.T) {
 	got := StarsRevenueStats(false)
 	if got == nil {

internal/rpc/account.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"github.com/iamxvbaba/td/tg"
+	"go.uber.org/zap"
 
 	"github.com/iamxvbaba/td/tlprofile"
 	"telesrv/internal/branding"
@@ -289,6 +290,7 @@ func (r *Router) registerAccount(d *tlprofile.Dispatcher) {
 			return false, tgerr400("WALLPAPER_INVALID")
 		}
 		if _, ok := tdesktop.LookupWallPaper(req.Wallpaper); !ok {
+			r.log.Info("wallpaper reference rejected", wallpaperReferenceLogFields("account.installWallPaper", req.Wallpaper)...)
 			return false, tgerr400("WALLPAPER_INVALID")
 		}
 		return true, nil
@@ -463,6 +465,20 @@ func (r *Router) registerAccount(d *tlprofile.Dispatcher) {
 
 }
 
+func wallpaperReferenceLogFields(method string, input tg.InputWallPaperClass) []zap.Field {
+	fields := []zap.Field{zap.String("method", method)}
+	switch wallpaper := input.(type) {
+	case *tg.InputWallPaperSlug:
+		return append(fields, zap.String("input_type", "inputWallPaperSlug"), zap.String("slug", wallpaper.Slug))
+	case *tg.InputWallPaper:
+		return append(fields, zap.String("input_type", "inputWallPaper"), zap.Int64("wallpaper_id", wallpaper.ID))
+	case *tg.InputWallPaperNoFile:
+		return append(fields, zap.String("input_type", "inputWallPaperNoFile"), zap.Int64("wallpaper_id", wallpaper.ID))
+	default:
+		return append(fields, zap.String("input_type", "unknown"))
+	}
+}
+
 func (r *Router) onAccountGetPassword(ctx context.Context) (*tg.AccountPassword, error) {
 	if r.deps.Account == nil {
 		return tgPassword(domain.PasswordSettings{SecureRandom: []byte("telesrv-tdesktop-dev-secure-rand")}), nil

internal/rpc/passive_compat_test.go

@@ -9,6 +9,8 @@ import (
 	"github.com/iamxvbaba/td/clock"
 	"github.com/iamxvbaba/td/tg"
 	"go.uber.org/zap/zaptest"
+
+	"telesrv/internal/compat/tdesktop"
 )
 
 func TestAccountGetChatThemesReturnsStaticThemes(t *testing.T) {
@@ -106,6 +108,21 @@ func TestAccountWallpaperSeedLookupAndAckRPCs(t *testing.T) {
 		t.Fatalf("getWallPaper id = %d, want %d", oneWallpaper.ID, first.ID)
 	}
 
+	defaultTheme := tdesktop.DefaultThemeList()[0]
+	themeAliasInput := &tg.InputWallPaperSlug{Slug: defaultTheme.Slug}
+	var aliasReq bin.Buffer
+	if err := (&tg.AccountGetWallPaperRequest{Wallpaper: themeAliasInput}).Encode(&aliasReq); err != nil {
+		t.Fatalf("encode getWallPaper theme alias request: %v", err)
+	}
+	aliasGot, err := r.Dispatch(ctx, [8]byte{}, 0, &aliasReq)
+	if err != nil {
+		t.Fatalf("dispatch getWallPaper theme alias: %v", err)
+	}
+	aliasWallpaper, ok := aliasGot.(*tg.WallPaper)
+	if !ok || aliasWallpaper.Slug == defaultTheme.Slug {
+		t.Fatalf("getWallPaper theme alias = %#v, want resolved wallpaper identity", aliasGot)
+	}
+
 	nofileInput := &tg.InputWallPaperNoFile{ID: 930000000000000001}
 	var nofileReq bin.Buffer
 	if err := (&tg.AccountGetWallPaperRequest{Wallpaper: nofileInput}).Encode(&nofileReq); err != nil {
@@ -127,6 +144,7 @@ func TestAccountWallpaperSeedLookupAndAckRPCs(t *testing.T) {
 	if err := (&tg.AccountGetMultiWallPapersRequest{Wallpapers: []tg.InputWallPaperClass{
 		input,
 		&tg.InputWallPaperSlug{Slug: first.Slug},
+		themeAliasInput,
 		nofileInput,
 	}}).Encode(&multiReq); err != nil {
 		t.Fatalf("encode getMultiWallPapers request: %v", err)
@@ -135,16 +153,18 @@ func TestAccountWallpaperSeedLookupAndAckRPCs(t *testing.T) {
 	if err != nil {
 		t.Fatalf("dispatch getMultiWallPapers: %v", err)
 	}
-	if vector, ok := dispatchCanonicalValue(multiGot).([]tg.WallPaperClass); !ok || len(vector) != 3 {
+	if vector, ok := dispatchCanonicalValue(multiGot).([]tg.WallPaperClass); !ok || len(vector) != 4 {
-		t.Fatalf("getMultiWallPapers = %T %#v, want 3 wallpapers", multiGot, multiGot)
+		t.Fatalf("getMultiWallPapers = %T %#v, want 4 wallpapers", multiGot, multiGot)
 	}
 
 	for name, request := range map[string]bin.Encoder{
-		"save":           &tg.AccountSaveWallPaperRequest{Wallpaper: input},
+		"save":                &tg.AccountSaveWallPaperRequest{Wallpaper: input},
-		"install":        &tg.AccountInstallWallPaperRequest{Wallpaper: input},
+		"install":             &tg.AccountInstallWallPaperRequest{Wallpaper: input},
-		"save_nofile":    &tg.AccountSaveWallPaperRequest{Wallpaper: nofileInput},
+		"save_theme_alias":    &tg.AccountSaveWallPaperRequest{Wallpaper: themeAliasInput},
-		"install_nofile": &tg.AccountInstallWallPaperRequest{Wallpaper: nofileInput},
+		"install_theme_alias": &tg.AccountInstallWallPaperRequest{Wallpaper: themeAliasInput},
-		"reset":          &tg.AccountResetWallPapersRequest{},
+		"save_nofile":         &tg.AccountSaveWallPaperRequest{Wallpaper: nofileInput},
+		"install_nofile":      &tg.AccountInstallWallPaperRequest{Wallpaper: nofileInput},
+		"reset":               &tg.AccountResetWallPapersRequest{},
 	} {
 		var encoded bin.Buffer
 		if err := request.Encode(&encoded); err != nil {
@@ -166,6 +186,14 @@ func TestAccountWallpaperSeedLookupAndAckRPCs(t *testing.T) {
 	if _, err := r.Dispatch(ctx, [8]byte{}, 0, &badReq); err == nil || !strings.Contains(err.Error(), "WALLPAPER_INVALID") {
 		t.Fatalf("bad getWallPaper err = %v, want WALLPAPER_INVALID", err)
 	}
+
+	var unknownAliasReq bin.Buffer
+	if err := (&tg.AccountInstallWallPaperRequest{Wallpaper: &tg.InputWallPaperSlug{Slug: "unknown-theme-alias"}}).Encode(&unknownAliasReq); err != nil {
+		t.Fatalf("encode unknown theme alias install request: %v", err)
+	}
+	if _, err := r.Dispatch(ctx, [8]byte{}, 0, &unknownAliasReq); err == nil || !strings.Contains(err.Error(), "WALLPAPER_INVALID") {
+		t.Fatalf("unknown theme alias install err = %v, want WALLPAPER_INVALID", err)
+	}
 }
 
 func TestPaymentsGetStarGiftCollectionsNoServiceFallbackAndValidatesPeer(t *testing.T) {