fix(tui): disable OSC 66 text-sizing on VTE-based terminals to prevent garbled output

packages/opencode/src/cli/cmd/tui/app.tsx

@@ -67,7 +67,7 @@ import { TuiConfigProvider, useTuiConfig } from "./context/tui-config"
 import { TuiConfig } from "@/cli/cmd/tui/config/tui"
 import { createTuiApi, TuiPluginRuntime, type RouteMap } from "./plugin"
 import { FormatError, FormatUnknownError } from "@/cli/error"
-import { isPlainTerminal } from "./util/terminal"
+import { isPlainTerminal, needsTextSizingDisabled } from "./util/terminal"
 
 import type { EventSource } from "./context/sdk"
 import { DialogVariant } from "./component/dialog-variant"
@@ -149,6 +149,31 @@ export function tui(input: {
     }
 
     const plainTerminal = isPlainTerminal()
+
+    // VTE-based terminals (MATE Terminal, GNOME Terminal, etc.) do not support
+    // the OSC 66 explicit-width protocol used by opentui. When unsupported, VTE
+    // prints the raw escape sequence as literal text ("]66;w=1;…"), and because
+    // this moves the cursor, opentui incorrectly concludes the terminal supports
+    // explicit_width and then emits OSC 66 for every rendered grapheme, causing
+    // continuous garbled output throughout the TUI.
+    //
+    // OPENTUI_FORCE_EXPLICIT_WIDTH=0 fixes this in two ways:
+    //   1. Sets skip_explicit_width_query=true → detection queries are never sent
+    //   2. Forces caps.explicit_width=false → rendering never emits OSC 66
+    //
+    // OPENTUI_FORCE_WCWIDTH=1 additionally uses the standard wcwidth algorithm
+    // for CJK character-width measurement instead of Unicode mode 2027, which
+    // VTE terminals also do not support.
+    //
+    // Both env vars must be set before createCliRenderer so the native Zig
+    // renderer picks them up when its constructor forwards env vars via
+    // setTerminalEnvVar (verified against @opentui/core 0.1.101). ??= leaves any
+    // explicit user-provided opentui override untouched.
+    if (needsTextSizingDisabled()) {
+      process.env.OPENTUI_FORCE_EXPLICIT_WIDTH ??= "0"
+      process.env.OPENTUI_FORCE_WCWIDTH ??= "1"
+    }
+
     const renderer = await createCliRenderer(rendererConfig(input.config, plainTerminal))
     // 默认使用 dark 模式(不跟随终端背景);用户手动切换后会被 theme_mode_lock 记住并优先。
     const mode = "dark"

packages/opencode/src/cli/cmd/tui/util/terminal.ts

@@ -16,6 +16,30 @@ export function isPlainTerminal(input?: { platform?: NodeJS.Platform; termProgra
   return isMacNativeTerminal(input)
 }
 
+/**
+ * Returns true when opentui's OSC 66 explicit-width protocol should be disabled.
+ *
+ * VTE-based terminals (MATE Terminal, GNOME Terminal, Xfce Terminal, etc.) do
+ * not understand OSC 66. Instead of ignoring the sequence they print it as
+ * literal text, which moves the cursor. opentui reads the cursor movement as a
+ * positive capability signal, then emits OSC 66 for every rendered grapheme,
+ * which VTE again prints literally—causing continuous garbled output in the TUI.
+ *
+ * VTE exports VTE_VERSION automatically, so that is used as the detection signal.
+ * Users can override auto-detection with MIMOCODE_DISABLE_TEXT_SIZING:
+ *   =1  force-disable (apply the workaround regardless of terminal type)
+ *   =0  force-enable  (skip the workaround even on VTE terminals)
+ */
+export function needsTextSizingDisabled(input?: { vteVersion?: string; disableTextSizing?: string }): boolean {
+  const disable = input?.disableTextSizing ?? process.env.MIMOCODE_DISABLE_TEXT_SIZING
+  if (disable === "false" || disable === "0") return false
+  if (disable === "true" || disable === "1") return true
+  // VTE_VERSION is set by all VTE-based terminals (MATE Terminal, GNOME Terminal,
+  // Xfce Terminal, Tilix, Guake, etc.)
+  const vteVersion = input?.vteVersion ?? process.env.VTE_VERSION
+  return vteVersion !== undefined && vteVersion !== ""
+}
+
 function parse(color: string): RGBA | null {
   if (color.startsWith("rgb:")) {
     const parts = color.substring(4).split("/")

packages/opencode/test/cli/tui/terminal.test.ts

@@ -0,0 +1,58 @@
+import { expect, test, describe } from "bun:test"
+
+const { needsTextSizingDisabled, isMacNativeTerminal, isPlainTerminal } = await import(
+  "../../../src/cli/cmd/tui/util/terminal"
+)
+
+describe("needsTextSizingDisabled", () => {
+  test("returns true for VTE terminals (VTE_VERSION set)", () => {
+    // MATE Terminal / GNOME Terminal export a numeric VTE_VERSION like "6800".
+    expect(needsTextSizingDisabled({ vteVersion: "6800" })).toBe(true)
+  })
+
+  test("returns false on a non-VTE terminal with no override", () => {
+    expect(needsTextSizingDisabled({})).toBe(false)
+  })
+
+  test("treats an empty VTE_VERSION as not-a-VTE", () => {
+    expect(needsTextSizingDisabled({ vteVersion: "" })).toBe(false)
+  })
+
+  test("MIMOCODE_DISABLE_TEXT_SIZING=1/true forces the workaround on any terminal", () => {
+    expect(needsTextSizingDisabled({ disableTextSizing: "1" })).toBe(true)
+    expect(needsTextSizingDisabled({ disableTextSizing: "true" })).toBe(true)
+  })
+
+  test("MIMOCODE_DISABLE_TEXT_SIZING=0/false overrides VTE auto-detection", () => {
+    // Explicit opt-out must win even when VTE_VERSION is present.
+    expect(needsTextSizingDisabled({ vteVersion: "6800", disableTextSizing: "0" })).toBe(false)
+    expect(needsTextSizingDisabled({ vteVersion: "6800", disableTextSizing: "false" })).toBe(false)
+  })
+
+  test("an unrecognized MIMOCODE_DISABLE_TEXT_SIZING value falls back to VTE auto-detection", () => {
+    expect(needsTextSizingDisabled({ vteVersion: "6800", disableTextSizing: "maybe" })).toBe(true)
+    expect(needsTextSizingDisabled({ disableTextSizing: "maybe" })).toBe(false)
+  })
+})
+
+describe("isMacNativeTerminal", () => {
+  test("true only for Apple_Terminal on darwin", () => {
+    expect(isMacNativeTerminal({ platform: "darwin", termProgram: "Apple_Terminal" })).toBe(true)
+    expect(isMacNativeTerminal({ platform: "darwin", termProgram: "iTerm.app" })).toBe(false)
+    expect(isMacNativeTerminal({ platform: "linux", termProgram: "Apple_Terminal" })).toBe(false)
+  })
+})
+
+describe("isPlainTerminal", () => {
+  test("MIMOCODE_TUI_PLAIN overrides terminal heuristics", () => {
+    expect(isPlainTerminal({ plain: "1" })).toBe(true)
+    expect(isPlainTerminal({ plain: "true" })).toBe(true)
+    expect(isPlainTerminal({ plain: "0", platform: "darwin", termProgram: "Apple_Terminal" })).toBe(false)
+    expect(isPlainTerminal({ plain: "false", platform: "darwin", termProgram: "Apple_Terminal" })).toBe(false)
+  })
+
+  test("defaults to mac-native detection when MIMOCODE_TUI_PLAIN is unset", () => {
+    expect(isPlainTerminal({ platform: "darwin", termProgram: "Apple_Terminal" })).toBe(true)
+    expect(isPlainTerminal({ platform: "linux", termProgram: "xterm" })).toBe(false)
+  })
+})