Fixed terminal bug. Fixed tests which could leave the system without proper accessibility setup which could cause cthulhu to fail to start.

internal/app/event_accessibility.go

@@ -278,6 +278,10 @@ func (handler *accessibilityEventHandler) handle(event atspi.Event) {
 		return
 	}
 	if event.Type == atspi.TextDeletedEvent && event.Source.Role == "terminal" {
+		if should_ignore_terminal_scrollback(event) {
+			logger.Debug("skipped terminal scrollback deletion", "role", event.Source.Role)
+			return
+		}
 		state.pending.terminalDeletion.schedule(event, input.NoIntent, terminalMutationDebounce)
 		return
 	}

internal/app/terminal_events.go

@@ -0,0 +1,19 @@
+// Cthulhu screen reader.
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package app
+
+import "git.stormux.org/storm/cthulhu/internal/atspi"
+
+func should_ignore_terminal_scrollback(event atspi.Event) bool {
+	// VTE can remove old complete lines at the start of its accessible text
+	// while appending output at a different offset. These are not edits to
+	// the prompt. This event pattern occurs on both X11 and Wayland.
+	return event.Type == atspi.TextDeletedEvent &&
+		event.Source.Role == "terminal" && event.Detail1 == 0 &&
+		event.Source.TextCaretKnown && event.Source.BrailleLineStart > 0 &&
+		event.TextChangeEndsLine && event.TextChangeLength > 0 &&
+		event.TextChangeLength <= event.Source.BrailleLineStart
+}

internal/app/terminal_events_test.go

@@ -20,12 +20,120 @@ package app
 import (
 	"context"
 	"log/slog"
+	"strings"
 	"testing"
 	"time"
 
 	"git.stormux.org/storm/cthulhu/internal/atspi"
 )
 
+func TestProcessEventsTerminalScrollbackDeletionBothSessions(t *testing.T) {
+	for _, sessionType := range []string{"wayland", "x11"} {
+		t.Run(sessionType, func(t *testing.T) {
+			t.Setenv("XDG_SESSION_TYPE", sessionType)
+			// Both sessions must apply the same event policy, including
+			// an X11 launcher which also supplies WAYLAND_DISPLAY.
+			t.Setenv("WAYLAND_DISPLAY", "wayland-test")
+			speech := &fakeSpeechQueue{spoken: make(chan string, 3)}
+			adapter := &fakeAdapter{events: make(chan atspi.Event, 3)}
+			ctx, cancel := context.WithCancel(context.Background())
+			completed := make(chan struct{})
+			go func() {
+				defer close(completed)
+				processEvents(ctx, slog.New(slog.DiscardHandler), speech, adapter, 0)
+			}()
+			t.Cleanup(func() {
+				cancel()
+				select {
+				case <-completed:
+				case <-time.After(time.Second):
+					t.Error("event loop did not stop")
+				}
+			})
+
+			terminal := atspi.NewSnapshot("/accessible/terminal", "", "terminal", "", "Username@Host> ")
+			terminal.TextCaretKnown = true
+			terminal.BrailleLineStart = 300
+			terminal.BrailleCaret = 315
+			oldPrompt := "Username@Host> old command\n"
+			deletion := atspi.NewEventWithPayload(atspi.TextDeletedEvent, terminal, oldPrompt)
+			output := atspi.NewEventWithPayload(atspi.TextInsertedEvent, terminal, "Current command output")
+			output.Detail1 = 200
+			// A caret event can arrive between the scroll and its insertion.
+			caret := atspi.NewEvent(atspi.CaretEvent, terminal)
+			adapter.events <- deletion
+			adapter.events <- caret
+			adapter.events <- output
+
+			for _, want := range []string{"Current command output"} {
+				select {
+				case got := <-speech.spoken:
+					if got != want {
+						t.Fatalf("speech = %q, want %q", got, want)
+					}
+				case <-time.After(time.Second):
+					t.Fatalf("timed out waiting for %q", want)
+				}
+			}
+			for _, deleted := range []string{"x", "command"} {
+				edit := atspi.NewEventWithPayload(atspi.TextDeletedEvent, terminal, deleted)
+				edit.Detail1 = terminal.BrailleLineStart
+				adapter.events <- edit
+				select {
+				case got := <-speech.spoken:
+					if got != deleted {
+						t.Fatalf("editing speech = %q, want %q", got, deleted)
+					}
+				case <-time.After(time.Second):
+					t.Fatalf("timed out waiting for deletion %q", deleted)
+				}
+			}
+		})
+	}
+}
+
+func TestTerminalScrollbackDeletionPreservesEditing(t *testing.T) {
+	t.Setenv("XDG_SESSION_TYPE", "wayland")
+	terminal := atspi.NewSnapshot("/accessible/terminal", "", "terminal", "", "Prompt")
+	terminal.TextCaretKnown = true
+	terminal.BrailleLineStart = 100
+	terminal.BrailleCaret = 110
+	base := atspi.NewEventWithPayload(atspi.TextDeletedEvent, terminal, "Old prompt\n")
+	for _, test := range []struct {
+		name   string
+		modify func(*atspi.Event)
+		ignore bool
+	}{
+		{"scroll", func(event *atspi.Event) {}, true},
+		{"unicode offsets", func(event *atspi.Event) {
+			*event = atspi.NewEventWithPayload(atspi.TextDeletedEvent, terminal, strings.Repeat("猫", 40)+"\n")
+		}, true},
+		{"backspace", func(event *atspi.Event) { event.Payload = "x"; event.Detail1 = 109 }, false},
+		{"delete", func(event *atspi.Event) { event.Payload = "x"; event.Detail1 = 110 }, false},
+		{"delete word", func(event *atspi.Event) { event.Payload = "command"; event.Detail1 = 100 }, false},
+		{"first character", func(event *atspi.Event) {
+			*event = atspi.NewEventWithPayload(atspi.TextDeletedEvent, terminal, "x")
+		}, false},
+		{"newline", func(event *atspi.Event) { event.Payload = "\n"; event.Detail1 = 100 }, false},
+		{"current first line", func(event *atspi.Event) { event.Source.BrailleLineStart = 0 }, false},
+		{"range reaches current line", func(event *atspi.Event) { event.Source.BrailleLineStart = 5 }, false},
+		{"unknown caret", func(event *atspi.Event) { event.Source.TextCaretKnown = false }, false},
+		{"partial line", func(event *atspi.Event) {
+			*event = atspi.NewEventWithPayload(atspi.TextDeletedEvent, terminal, "Old prompt")
+		}, false},
+		{"editor", func(event *atspi.Event) { event.Source.Role = "text" }, false},
+		{"insertion", func(event *atspi.Event) { event.Type = atspi.TextInsertedEvent }, false},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			event := base
+			test.modify(&event)
+			if got := should_ignore_terminal_scrollback(event); got != test.ignore {
+				t.Fatalf("ignore = %v, want %v", got, test.ignore)
+			}
+		})
+	}
+}
+
 func TestProcessEventsCoalescesTerminalDeletionWithReplacementInsertion(t *testing.T) {
 	speech := &fakeSpeechQueue{spoken: make(chan string, 3)}
 	adapter := &fakeAdapter{events: make(chan atspi.Event, 3)}

internal/atspi/model.go

@@ -295,6 +295,10 @@ type Event struct {
 	OriginPath string
 	Payload    string
 	Detail1    int
+	// TextChangeLength and TextChangeEndsLine describe the original payload,
+	// before speech normalization collapses whitespace and limits its length.
+	TextChangeLength   int
+	TextChangeEndsLine bool
 }
 
 type ForegroundCheck struct {
@@ -375,6 +379,10 @@ func NewManagedDescendantEvent(eventType, originPath string, source Snapshot) Ev
 func NewEventWithPayload(eventType string, source Snapshot, payload string) Event {
 	event := NewEvent(eventType, source)
 	event.Payload = sanitizeTextPayload(payload)
+	if event.Type == TextInsertedEvent || event.Type == TextDeletedEvent {
+		event.TextChangeLength = utf8.RuneCountInString(payload)
+		event.TextChangeEndsLine = strings.HasSuffix(payload, "\n")
+	}
 	return event
 }
 

internal/atspi/model_test.go

@@ -181,6 +181,16 @@ func TestNewEventWithPayloadSanitizesPayload(t *testing.T) {
 	}
 }
 
+func TestTextChangeRetainsOriginalRangeMetadata(t *testing.T) {
+	source := NewSnapshot("/accessible/terminal", "", "terminal", "", "")
+	for _, eventType := range []string{TextInsertedEvent, TextDeletedEvent, TextDeletedEvent + ":system"} {
+		event := NewEventWithPayload(eventType, source, "猫  command\r\n")
+		if event.Payload != "猫 command" || event.TextChangeLength != 12 || !event.TextChangeEndsLine {
+			t.Fatalf("text change = %#v", event)
+		}
+	}
+}
+
 func TestNewEventWithPayloadPreservesInsertedSpace(t *testing.T) {
 	event := NewEventWithPayload(TextInsertedEvent, NewSnapshot("/accessible/editor", "", "text", "", ""), " ")
 	if event.Payload != " " {