TUI composer inserts a blank row after an exact-width word

What version of Codex CLI is running?

codex-cli 0.147.0

What subscription do you have?

Pro 20x

Which model were you using?

gpt-5.6 Sol

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What terminal emulator and version are you using (if applicable)?

Windows Terminal Canary 1.26.2182.0 with PowerShell 7.6.4. No terminal multiplexer.

Codex doctor report

{
  "schemaVersion": 1,
  "generatedAt": "1786228035s since unix epoch",
  "overallStatus": "ok",
  "codexVersion": "0.148.0-alpha.5",
  "checks": {
    "app_server.status": {
      "id": "app_server.status",
      "category": "app-server",
      "status": "ok",
      "summary": "background server is not running",
      "details": {
        "control socket": "C:\\Users\\micro\\.codex\\app-server-control\\app-server-control.sock",
        "daemon state dir": "C:\\Users\\micro\\.codex\\app-server-daemon",
        "mode": "ephemeral",
        "pid file": "C:\\Users\\micro\\.codex\\app-server-daemon\\app-server.pid (missing)",
        "settings": "C:\\Users\\micro\\.codex\\app-server-daemon\\settings.json (missing)",
        "status": "not running",
        "update-loop pid file": "C:\\Users\\micro\\.codex\\app-server-daemon\\app-server-updater.pid (missing)"
      },
      "remediation": null,
      "durationMs": 0
    },
    "auth.credentials": {
      "id": "auth.credentials",
      "category": "auth",
      "status": "ok",
      "summary": "auth is configured",
      "details": {
        "auth file": "C:\\Users\\micro\\.codex\\auth.json",
        "auth storage mode": "File",
        "stored API key": "false",
        "stored ChatGPT tokens": "true",
        "stored agent identity": "false",
        "stored auth mode": "chatgpt"
      },
      "remediation": null,
      "durationMs": 0
    },
    "config.load": {
      "id": "config.load",
      "category": "config",
      "status": "ok",
      "summary": "config loaded",
      "details": {
        "CODEX_HOME": "C:\\Users\\micro\\.codex",
        "config.toml": "C:\\Users\\micro\\.codex\\config.toml",
        "config.toml parse": "ok",
        "cwd": "C:\\Users\\micro\\Documents\\projects\\subaru-ecu-research",
        "enabled feature flags": "<redacted>",
        "feature flag overrides": "none",
        "feature flags enabled": "39",
        "log dir": "C:\\Users\\micro\\.codex\\log",
        "mcp servers": "5",
        "model": "gpt-5.6-sol",
        "model provider": "openai",
        "sqlite home": "C:\\Users\\micro\\.codex"
      },
      "remediation": null,
      "durationMs": 0
    },
    "git.environment": {
      "id": "git.environment",
      "category": "git",
      "status": "ok",
      "summary": "git version 2.55.0.windows.2",
      "details": {
        ".git entry": "directory",
        "PATH git #1": "C:\\Program Files\\Git\\cmd\\git.exe",
        "PATH git entries": "1",
        "git branch": "main",
        "git build options": "git version 2.55.0.windows.2; cpu: x86_64; built from commit: c8dff95af823bd04181a583c03f3fbb954551c30; sizeof-long: 4; sizeof-size_t: 8; shell-path: D:/git-sdk-64-build-installers/usr/bin/sh; rust: disabled; feature: fsmonitor--daemon; gettext: enabled; libcurl: 8.21.0; OpenSSL: OpenSSL 3.5.7 9 Jun 2026; zlib: 1.3.2; SHA-1: SHA1_DC; SHA-256: SHA256_BLK; default-ref-format: files; default-hash: sha1",
        "git exec path": "C:/Program Files/Git/mingw64/libexec/git-core",
        "git version": "git version 2.55.0.windows.2",
        "repo detected": "true",
        "repo root": "C:\\Users\\micro\\Documents\\projects\\subaru-ecu-research",
        "selected git": "C:\\Program Files\\Git\\cmd\\git.exe"
      },
      "remediation": null,
      "durationMs": 82
    },
    "installation": {
      "id": "installation",
      "category": "install",
      "status": "ok",
      "summary": "installation looks consistent",
      "details": {
        "PATH codex #1": "C:\\Users\\micro\\AppData\\Local\\Programs\\OpenAI\\Codex\\bin\\codex.exe",
        "current executable": "C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\bin\\codex.exe",
        "install context": "other (package C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5, bin C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\bin, resources C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\codex-resources, path C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\codex-path)",
        "managed by bun": "false",
        "managed by npm": "false",
        "managed by pnpm": "false",
        "managed package root": "not set"
      },
      "remediation": null,
      "durationMs": 45
    },
    "mcp.config": {
      "id": "mcp.config",
      "category": "mcp",
      "status": "ok",
      "summary": "MCP configuration is locally consistent",
      "details": {
        "configured servers": "5",
        "disabled servers": "4",
        "stdio servers": "1",
        "streamable_http servers": "4"
      },
      "remediation": null,
      "durationMs": 38
    },
    "network.env": {
      "id": "network.env",
      "category": "network",
      "status": "ok",
      "summary": "network-related environment looks readable",
      "details": {
        "proxy env vars": "none"
      },
      "remediation": null,
      "durationMs": 0
    },
    "network.provider_reachability": {
      "id": "network.provider_reachability",
      "category": "reachability",
      "status": "ok",
      "summary": "active provider endpoints are reachable over HTTP",
      "details": {
        "ChatGPT base URL": "https://chatgpt.com/backend-api/ reachable (HTTP 403)",
        "reachability mode": "ChatGPT auth"
      },
      "remediation": null,
      "durationMs": 92
    },
    "network.websocket_reachability": {
      "id": "network.websocket_reachability",
      "category": "websocket",
      "status": "ok",
      "summary": "Responses WebSocket handshake succeeded",
      "details": {
        "DNS": "2 IPv4, 0 IPv6, first IPv4",
        "auth mode": "chatgpt",
        "connect timeout": "15000 ms",
        "endpoint": "wss://chatgpt.com/backend-api/<redacted>",
        "handshake result": "HTTP 101 Switching Protocols",
        "model provider": "openai",
        "models etag present": "true",
        "provider name": "OpenAI",
        "proxy env vars": "none",
        "reasoning header": "false",
        "server model present": "false",
        "supports websockets": "true",
        "wire API": "responses"
      },
      "remediation": null,
      "durationMs": 662
    },
    "runtime.provenance": {
      "id": "runtime.provenance",
      "category": "runtime",
      "status": "ok",
      "summary": "running local build on windows-x86_64",
      "details": {
        "commit": "unknown",
        "current executable": "C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\bin\\codex.exe",
        "install method": "other (package C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5, bin C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\bin, resources C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\codex-resources, path C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\codex-path)",
        "platform": "windows-x86_64",
        "version": "0.148.0-alpha.5"
      },
      "remediation": null,
      "durationMs": 0
    },
    "runtime.search": {
      "id": "runtime.search",
      "category": "search",
      "status": "ok",
      "summary": "search is OK (bundled)",
      "details": {
        "search command": "C:\\Users\\micro\\AppData\\Local\\Temp\\codex-official-0.148.0-alpha.5\\codex-path\\rg.exe",
        "search command readiness": "file exists",
        "search provider": "bundled"
      },
      "remediation": null,
      "durationMs": 0
    },
    "sandbox.helpers": {
      "id": "sandbox.helpers",
      "category": "sandbox",
      "status": "ok",
      "summary": "sandbox configuration is readable",
      "details": {
        "approval policy": "OnRequest",
        "codex-linux-sandbox helper": "none",
        "execve wrapper helper": "none",
        "filesystem sandbox": "restricted",
        "network sandbox": "restricted"
      },
      "remediation": null,
      "durationMs": 0
    },
    "state.paths": {
      "id": "state.paths",
      "category": "state",
      "status": "ok",
      "summary": "state paths and databases are inspectable",
      "details": {
        "CODEX_HOME": "C:\\Users\\micro\\.codex (dir)",
        "active rollout files": "309 files, 1408771752 total bytes, 4559131 average bytes",
        "archived rollout files": "0 files, 0 total bytes, 0 average bytes",
        "goals DB": "C:\\Users\\micro\\.codex\\goals_1.sqlite (file)",
        "goals DB integrity": "ok",
        "log DB": "C:\\Users\\micro\\.codex\\logs_2.sqlite (file)",
        "log DB integrity": "ok",
        "log dir": "C:\\Users\\micro\\.codex\\log (missing)",
        "memories DB": "C:\\Users\\micro\\.codex\\memories_1.sqlite (file)",
        "memories DB integrity": "ok",
        "queue DB": "C:\\Users\\micro\\.codex\\queue_1.sqlite (file)",
        "queue DB integrity": "ok",
        "sqlite home": "C:\\Users\\micro\\.codex (dir)",
        "state DB": "C:\\Users\\micro\\.codex\\state_5.sqlite (file)",
        "state DB integrity": "ok",
        "thread history DB": "C:\\Users\\micro\\.codex\\thread_history_1.sqlite (file)",
        "thread history DB integrity": "ok"
      },
      "remediation": null,
      "durationMs": 1164
    },
    "state.rollout_db_parity": {
      "id": "state.rollout_db_parity",
      "category": "threads",
      "status": "ok",
      "summary": "rollout files and state DB thread inventory agree",
      "details": {
        "default model provider": "openai",
        "rollout DB active files": "309",
        "rollout DB active rows": "309",
        "rollout DB archive mismatches": "0",
        "rollout DB archived files": "0",
        "rollout DB archived rows": "0",
        "rollout DB duplicate DB paths": "0",
        "rollout DB duplicate rollout thread ids": "0",
        "rollout DB malformed file names": "0",
        "rollout DB missing active rows": "0",
        "rollout DB missing archived rows": "0",
        "rollout DB model providers": "openai=309",
        "rollout DB rows": "309",
        "rollout DB scan cap reached": "false",
        "rollout DB scan errors": "0",
        "rollout DB sources": "subagent:thread_spawn=199, subagent:other=62, cli=47, unknown=1",
        "rollout DB stale rows": "0"
      },
      "remediation": null,
      "durationMs": 224
    },
    "system.environment": {
      "id": "system.environment",
      "category": "system",
      "status": "ok",
      "summary": "OS language en-US",
      "details": {
        "EDITOR": "set",
        "PAGER": "set",
        "VISUAL": "not set",
        "os": "Windows 10.0.26200 (Windows 11 Professional) [64-bit]",
        "os language": "en-US",
        "os type": "Windows",
        "os version": "10.0.26200"
      },
      "remediation": null,
      "durationMs": 0
    },
    "terminal.env": {
      "id": "terminal.env",
      "category": "terminal",
      "status": "ok",
      "summary": "terminal metadata was detected",
      "details": {
        "COLORTERM": "truecolor",
        "WT_SESSION": "present",
        "color output": "disabled (stdout is not a terminal)",
        "console input code page": "437",
        "console output code page": "437",
        "stderr console mode": "0x00000007 (VT processing: true)",
        "stderr is terminal": "true",
        "stdin is terminal": "true",
        "stdout console mode": "unavailable",
        "stdout is terminal": "false",
        "terminal": "Windows Terminal",
        "terminal size": "156x36"
      },
      "remediation": null,
      "durationMs": 0
    },
    "terminal.title": {
      "id": "terminal.title",
      "category": "title",
      "status": "ok",
      "summary": "terminal title default",
      "details": {
        "terminal title activity": "true",
        "terminal title items": "activity, project-name",
        "terminal title project source": "git repo root",
        "terminal title project value": "subaru-ecu-research",
        "terminal title source": "default"
      },
      "remediation": null,
      "durationMs": 0
    },
    "updates.status": {
      "id": "updates.status",
      "category": "updates",
      "status": "ok",
      "summary": "update configuration is locally consistent",
      "details": {
        "cached latest version": "0.147.0",
        "check for update on startup": "true",
        "last checked at": "2026-08-08T16:38:58.645428900Z",
        "latest version": "0.147.0",
        "latest version status": "current version is not older",
        "update action": "manual or unknown",
        "version cache": "C:\\Users\\micro\\.codex\\version.json"
      },
      "remediation": null,
      "durationMs": 356
    }
  }
}

What issue are you seeing?

The prompt composer inserts an apparently empty row when a word ends exactly at the last available column and the next character is a single ASCII space.

The space is assigned its own visual row. Because the separator is invisible, the following word appears one row too low. Adding one character earlier in the prompt forces a normal word wrap and immediately removes the blank row.

This also makes the cursor and composer height change unexpectedly while editing across the boundary.

What steps can reproduce the bug?

1. Start the Codex CLI TUI.
2. Type a prompt whose final word ends exactly at the last available composer column.
3. Type one ASCII space, then continue typing the next word.
4. Observe an empty visual row between the exactly full row and the following visible text.
5. Insert one character earlier in the prompt so the preceding word wraps normally.
6. Observe that the empty row disappears.

Minimal layout example:

    textarea width: 4
    source text: "abad next"

    expected visible rows:
    abad
    next

    actual visible rows:
    abad

    next

What is the expected behavior?

The following visible text should render on the immediately adjacent row. A single soft-wrap separator must not occupy its own blank visual row, and cursor placement should remain correct while editing across the boundary.

Additional information

The defect is in generic textarea wrapping rather than Windows-specific terminal handling. At the exact-width boundary, the wrapping ranges contain a standalone single-space separator between a full row and the following visible text, and the composer renders that separator as a separate row.

The doctor report was captured later from official codex-cli 0.148.0-alpha.5 on the same computer and terminal environment; the screenshots show the original 0.147.0 reproduction.