tests: resolve zsh paths in redraw regressions

docs/ghostty-fork.md

@@ -45,8 +45,9 @@ Fork rebased onto upstream `v1.3.0` plus newer `main` commits as of March 12, 20
 
 ### 4) macOS resize stale-frame mitigation
 
-Sections 3 and 4 are grouped by feature, not by commit order. The fork branch HEAD is the
-section 3 copy-mode commit, even though the section 4 resize commits were applied earlier.
+Sections 3 and 4 are grouped by feature, not by commit order. The section 4 resize commits were
+applied earlier than the section 3 copy-mode commit, but they are kept together here because they
+touch the same stale-frame mitigation path and tend to conflict in the same files during rebases.
 
 - Commits:
   - `769bbf7a9` (macos: reduce transient blank/scaled frames during resize)

tests/test_ghostty_zsh_prompt_redraw_uses_prompt_start.py

@@ -73,10 +73,10 @@ zle -N zle-line-init _cmux_redraw_line_init
     )
 
 
-def _capture_session(env: dict[str, str]) -> bytes:
+def _capture_session(env: dict[str, str], zsh_path: str) -> bytes:
     master, slave = pty.openpty()
     proc = subprocess.Popen(
-        ["zsh", "-d", "-i"],
+        [zsh_path, "-d", "-i"],
         stdin=slave,
         stdout=slave,
         stderr=slave,
@@ -123,7 +123,8 @@ def main() -> int:
         print(f"SKIP: missing Ghostty zsh wrapper at {wrapper_dir}")
         return 0
 
-    if shutil.which("zsh") is None:
+    zsh_path = shutil.which("zsh")
+    if zsh_path is None:
         print("SKIP: zsh not installed")
         return 0
 
@@ -141,7 +142,7 @@ def main() -> int:
         env.pop("GHOSTTY_SHELL_FEATURES", None)
         env.pop("GHOSTTY_BIN_DIR", None)
 
-        output = _capture_session(env)
+        output = _capture_session(env, zsh_path)
 
         marker = output.find(END_COMMAND)
         if marker == -1:

tests/test_ghostty_zsh_pure_preprompt_redraw.py

@@ -89,7 +89,14 @@ PROMPT='%F{5}❯%f '
 _ANSI_RE = re.compile(rb"\x1b\][^\x07]*\x07|\x1b\[[0-9;?]*[ -/]*[@-~]|\r")
 
 
-def _capture_session(*, use_ghostty: bool, wrapper_dir: Path, resources_dir: Path, workdir: Path) -> str:
+def _capture_session(
+    *,
+    use_ghostty: bool,
+    wrapper_dir: Path,
+    resources_dir: Path,
+    workdir: Path,
+    zsh_path: str,
+) -> str:
     base = Path(tempfile.mkdtemp(prefix="cmux_ghostty_pure_preprompt_"))
     try:
         home = base / "home"
@@ -112,7 +119,7 @@ def _capture_session(*, use_ghostty: bool, wrapper_dir: Path, resources_dir: Pat
 
         master, slave = pty.openpty()
         proc = subprocess.Popen(
-            ["zsh", "-d", "-i"],
+            [zsh_path, "-d", "-i"],
             cwd=str(workdir),
             stdin=slave,
             stdout=slave,
@@ -174,7 +181,8 @@ def main() -> int:
     if not (wrapper_dir / ".zshenv").exists():
         print(f"SKIP: missing Ghostty zsh wrapper at {wrapper_dir}")
         return 0
-    if shutil.which("zsh") is None:
+    zsh_path = shutil.which("zsh")
+    if zsh_path is None:
         print("SKIP: zsh not installed")
         return 0
 
@@ -186,12 +194,14 @@ def main() -> int:
         wrapper_dir=wrapper_dir,
         resources_dir=resources_dir,
         workdir=workdir,
+        zsh_path=zsh_path,
     )
     ghostty = _capture_session(
         use_ghostty=True,
         wrapper_dir=wrapper_dir,
         resources_dir=resources_dir,
         workdir=workdir,
+        zsh_path=zsh_path,
     )
 
     plain_stale, plain_async = _stale_preprompt_lines(plain, path_line, async_line)