From 43335bc2495c597477fc140aefe066f552c3c294 Mon Sep 17 00:00:00 2001
From: onevcat <onevcat@gmail.com>
Date: Tue, 29 Sep 2026 09:14:44 +0900
Subject: [PATCH] Preserve caller argument boundaries and daemon log continuity

---
 docs/components/agent-detection.md            |  3 ++
 docs/components/cli.md                        |  2 ++
 .../AgentDetection/CodexLogProvider.swift     | 14 ++++++---
 .../AgentDetection/ProcessDetection.swift     |  9 ++++++
 supacodeTests/CodexLogProviderTests.swift     | 29 +++++++++++++++++++
 .../ProcessDetectionSmokeTests.swift          | 12 ++++++++
 6 files changed, 65 insertions(+), 4 deletions(-)

diff --git a/docs/components/agent-detection.md b/docs/components/agent-detection.md
index b08e87a0e..3b4349969 100644
--- a/docs/components/agent-detection.md
+++ b/docs/components/agent-detection.md
@@ -119,6 +119,9 @@ at a `~/.grok/` install (so Cursor's own `agent` entrypoint stays Cursor).
    Until the pane's Codex submits its first message, and for a moment after each
    new submit, detection falls back to the screen. A Codex launched from an Agent
    Profile or with `--no-daemon` owns its logs and is read directly.
+   If a previously established daemon binding becomes unavailable, detection falls
+   back to the screen but retains its log cursors. When the binding returns, it
+   consumes pending events without replaying earlier turn starts.
 
    Claude reads the detected PID's native registry under its configured root
    (`~/.claude/sessions` by default). `busy` and `shell` mean **Working**, including
diff --git a/docs/components/cli.md b/docs/components/cli.md
index 57f33f1e5..4c0fc8b34 100644
--- a/docs/components/cli.md
+++ b/docs/components/cli.md
@@ -132,6 +132,8 @@ the submitted prompts there (mode 0600); Prowl deletes the file once the pane's
 longer be undone. A pane whose Codex has not submitted anything yet, or whose shell
 overrides those variables, cannot be mapped, and caller-scoped commands fail with
 `SOURCE_REQUIRED`.
+Session logs larger than 64 MiB are not mapped. Restarting Codex in the pane resets its
+session log; its first indexed submit can establish the mapping again.
 Codex launched from an Agent Profile, or with `--no-daemon`, runs commands inside the pane
 and is not affected.
 
diff --git a/supacode/Infrastructure/AgentDetection/CodexLogProvider.swift b/supacode/Infrastructure/AgentDetection/CodexLogProvider.swift
index d66c96a47..62fae841d 100644
--- a/supacode/Infrastructure/AgentDetection/CodexLogProvider.swift
+++ b/supacode/Infrastructure/AgentDetection/CodexLogProvider.swift
@@ -57,10 +57,16 @@ actor CodexLogProvider {
       .compactMap { parse($0)?.transcriptPath }
     var liveOffsets: [URL: UInt64] = [:]
     // An embedded TUI owns its rollouts. A TUI that owns none may drive daemon threads.
-    if complete, paths.isEmpty, let daemonBinding, let binding = await daemonBinding(process, configRoot) {
-      paths = binding.paths.map { URL(filePath: $0, directoryHint: .notDirectory) }
-      for (path, offset) in binding.liveOffsets {
-        liveOffsets[URL(filePath: path, directoryHint: .notDirectory)] = offset
+    if complete, paths.isEmpty, let daemonBinding {
+      if let binding = await daemonBinding(process, configRoot) {
+        paths = binding.paths.map { URL(filePath: $0, directoryHint: .notDirectory) }
+        for (path, offset) in binding.liveOffsets {
+          liveOffsets[URL(filePath: path, directoryHint: .notDirectory)] = offset
+        }
+      } else if !cursors.isEmpty {
+        // A failed lookup does not prove that previously bound work disappeared.
+        // Suspend authority and keep the cursors until a complete binding returns.
+        complete = false
       }
     }
     let events = sample(paths: paths, inventoryComplete: complete, liveOffsets: liveOffsets)
diff --git a/supacode/Infrastructure/AgentDetection/ProcessDetection.swift b/supacode/Infrastructure/AgentDetection/ProcessDetection.swift
index fa89752ac..1a3e1799d 100644
--- a/supacode/Infrastructure/AgentDetection/ProcessDetection.swift
+++ b/supacode/Infrastructure/AgentDetection/ProcessDetection.swift
@@ -327,6 +327,15 @@ nonisolated enum ProcessDetection {
     }
 
     var strings: [String] = []
+    // Only the executable-path padding may contain extra NUL bytes. Within argv,
+    // each NUL ends one argument, including an empty one.
+    for _ in 0..<Int(argc) {
+      guard position < buffer.count, let end = buffer[position...].firstIndex(of: 0),
+        let value = String(bytes: buffer[position..<end], encoding: .utf8)
+      else { return nil }
+      strings.append(value)
+      position = end + 1
+    }
     while position < buffer.count {
       let start = position
       while position < buffer.count, buffer[position] != 0 {
diff --git a/supacodeTests/CodexLogProviderTests.swift b/supacodeTests/CodexLogProviderTests.swift
index 70c42449a..db907f790 100644
--- a/supacodeTests/CodexLogProviderTests.swift
+++ b/supacodeTests/CodexLogProviderTests.swift
@@ -287,6 +287,35 @@ struct CodexLogProviderTests {
     #expect(requested.withLock { $0 } == [configRoot as URL?])
   }
 
+  @Test func missingDaemonBindingSuspendsWithoutDiscardingProgress() async throws {
+    let directory = try fixture()
+    defer { try? FileManager.default.removeItem(at: directory) }
+    let path = directory.appending(path: "rollout-daemon.jsonl")
+    let prefix = header("root")
+    try (prefix + start("t1")).write(to: path, atomically: false, encoding: .utf8)
+    let started = try #require(ProcessDetection.processStartDate(pid: getpid()))
+    let process = AgentProcessGeneration(pid: getpid(), startedAt: started)
+    let available = Mutex(true)
+    let provider = CodexLogProvider(
+      startedAt: .distantFuture,
+      daemonBinding: { _, _ in
+        guard available.withLock({ $0 }) else { return nil }
+        return CodexDaemonBinding(
+          rootID: "root", paths: [path.path], liveOffsets: [path.path: UInt64(prefix.utf8.count)])
+      })
+
+    #expect(startedTurns(await provider.sample(process: process, configRoot: nil)) == ["t1"])
+    available.withLock { $0 = false }
+    let missing = await provider.sample(process: process, configRoot: nil)
+    if case .suspended = missing.first {} else { Issue.record("Missing binding must suspend") }
+    try append(complete("t1"), to: path)
+    available.withLock { $0 = true }
+    let recovered = await provider.sample(process: process, configRoot: nil)
+    #expect(startedTurns(recovered).isEmpty)
+    if case .turnEnded("root", "t1") = recovered.last {} else { Issue.record("Completion was lost") }
+    #expect(await provider.metadataReadCount == 1)
+  }
+
   @Test func managedDaemonPIDRequiresALiveDaemonProcess() throws {
     let home = try fixture()
     defer { try? FileManager.default.removeItem(at: home) }
diff --git a/supacodeTests/ProcessDetectionSmokeTests.swift b/supacodeTests/ProcessDetectionSmokeTests.swift
index 5e61d35ea..a485e3881 100644
--- a/supacodeTests/ProcessDetectionSmokeTests.swift
+++ b/supacodeTests/ProcessDetectionSmokeTests.swift
@@ -30,6 +30,18 @@ struct ProcessDetectionSmokeTests {
     #expect(ProcessDetection.procargs2Environment(buffer) == ["CODEX_THREAD_ID=abc", "PATH=/bin"])
   }
 
+  @Test func emptyArgumentsDoNotShiftTheEnvironmentBoundary() {
+    var buffer: [UInt8] = []
+    withUnsafeBytes(of: Int32(3)) { buffer.append(contentsOf: $0) }
+    for string in ["/usr/bin/prowl", "", "prowl", "", "list", "CODEX_THREAD_ID=abc", "PATH=/bin"] {
+      buffer.append(contentsOf: string.utf8)
+      buffer.append(0)
+    }
+
+    #expect(ProcessDetection.procargs2Argv(buffer) == ["prowl", "", "list"])
+    #expect(ProcessDetection.procargs2Environment(buffer) == ["CODEX_THREAD_ID=abc", "PATH=/bin"])
+  }
+
   // The kernel hides the environment of Apple platform binaries (`/bin/sleep`), so the test
   // reads its own host process, which, like the `prowl` CLI, is not one.
   @Test func readsAProcessLaunchEnvironmentValue() throws {