fix(opencode): remove double-ESC byte in tmux DCS passthrough for OSC 52

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

@@ -39,7 +39,7 @@ function writeOsc52(text: string): void {
   const base64 = Buffer.from(text).toString("base64")
   const osc52 = `\x1b]52;c;${base64}\x07`
   const passthrough = process.env["TMUX"] || process.env["STY"]
-  const sequence = passthrough ? `\x1bPtmux;\x1b${osc52}\x1b\\` : osc52
+  const sequence = passthrough ? `\x1bPtmux;${osc52}\x1b\\` : osc52
   process.stdout.write(sequence)
 }
 

packages/opencode/test/cli/cmd/tui/util/clipboard.test.ts

@@ -0,0 +1,123 @@
+import { describe, expect, test } from "bun:test"
+
+/** Temporarily set process.env.TMUX, restore afterwards, passthrough return value. */
+async function withTmux<T>(value: string | undefined, fn: () => Promise<T>): Promise<T> {
+  const before = process.env["TMUX"]
+  if (value === undefined) delete process.env["TMUX"]
+  else process.env["TMUX"] = value
+  try {
+    return await fn()
+  } finally {
+    if (before === undefined) delete process.env["TMUX"]
+    else process.env["TMUX"] = before
+  }
+}
+
+/** Temporarily set stdout.isTTY, restore afterwards, passthrough return value. */
+async function withTty<T>(value: boolean, fn: () => Promise<T>): Promise<T> {
+  const desc = Object.getOwnPropertyDescriptor(process.stdout, "isTTY")
+  Object.defineProperty(process.stdout, "isTTY", { configurable: true, value })
+  try {
+    return await fn()
+  } finally {
+    if (desc) {
+      Object.defineProperty(process.stdout, "isTTY", desc)
+    } else {
+      delete (process.stdout as any).isTTY
+    }
+  }
+}
+
+/** Replace process.stdout.write to collect writes into an array, restore afterwards. */
+async function captureStdoutWrite(fn: () => Promise<void>): Promise<Buffer[]> {
+  const bufs: Buffer[] = []
+  const origWrite = process.stdout.write.bind(process.stdout)
+  process.stdout.write = ((chunk: any) => {
+    bufs.push(Buffer.from(chunk))
+    return true
+  }) as typeof process.stdout.write
+  try {
+    await fn()
+    return bufs
+  } finally {
+    process.stdout.write = origWrite
+  }
+}
+
+describe("clipboard writeOsc52", () => {
+  test("emits plain OSC 52 without TMUX: ESC ] 5 2 ; c ; <b64> BEL", async () => {
+    const bufs = await withTty(true, () =>
+      withTmux(undefined, () =>
+        captureStdoutWrite(async () => {
+          const { copy } = await import("../../../../../src/cli/cmd/tui/util/clipboard")
+          await copy("hello").catch(() => {})
+        }),
+      ),
+    )
+
+    expect(bufs.length).toBeGreaterThanOrEqual(1)
+
+    const buf = bufs[0]!
+
+    // ESC ] 5 2 ; c ; aGVsbG8= BEL
+    expect(buf[0]).toBe(0x1b) // ESC
+    expect(buf[1]).toBe(0x5d) // ]
+    expect(buf.slice(2, 5).toString()).toBe("52;")
+    expect(buf.slice(5, 7).toString()).toBe("c;")
+    expect(buf.slice(7, 15).toString()).toBe("aGVsbG8=") // base64("hello")
+    expect(buf[buf.length - 1]).toBe(0x07) // BEL
+    expect(buf.filter((b) => b === 0x1b).length).toBe(1)
+  })
+
+  test("emits DCS-wrapped OSC 52 with TMUX: ESC P tmux ; ESC ] ... BEL ESC \\", async () => {
+    const bufs = await withTty(true, () =>
+      withTmux("ses", () =>
+        captureStdoutWrite(async () => {
+          const { copy } = await import("../../../../../src/cli/cmd/tui/util/clipboard")
+          await copy("x").catch(() => {})
+        }),
+      ),
+    )
+
+    expect(bufs.length).toBeGreaterThanOrEqual(1)
+
+    const buf = bufs[0]!
+
+    // DCS prefix: ESC P t m u x ;
+    expect(buf[0]).toBe(0x1b)
+    expect(buf[1]).toBe(0x50)
+    expect(buf.slice(2, 7).toString()).toBe("tmux;")
+
+    // Immediately after "tmux;" we must have ESC ] (1b 5d), NOT ESC ESC (1b 1b)
+    expect(buf[7]).toBe(0x1b)
+    expect(buf[8]).toBe(0x5d)
+    // ^ If there were a double-ESC bug, buf[8] would be 0x1b
+
+    // OSC 52 content inside DCS wrapper
+    expect(buf.slice(7, 9).toString()).toBe("\x1b]")
+    expect(buf.slice(9, 12).toString()).toBe("52;")
+    expect(buf.slice(12, 14).toString()).toBe("c;")
+
+    // DCS terminator: ESC \
+    expect(buf[buf.length - 2]).toBe(0x1b)
+    expect(buf[buf.length - 1]).toBe(0x5c)
+
+    // CRITICAL: exactly 3 ESC bytes (no double-ESC bug)
+    expect(buf.filter((b) => b === 0x1b).length).toBe(3)
+  })
+
+  test("skips OSC 52 write when stdout is not a TTY", async () => {
+    const bufs = await withTty(false, () =>
+      withTmux(undefined, () =>
+        captureStdoutWrite(async () => {
+          const { copy } = await import("../../../../../src/cli/cmd/tui/util/clipboard")
+          await copy("data").catch(() => {})
+        }),
+      ),
+    )
+
+    for (const b of bufs) {
+      expect(b.toString()).not.toMatch(/\x1b\]52;c;/)
+    }
+  })
+})