fuzz tests: exercise --panel with waybar (launch, cycle, teardown)

tests/test_fuzz.py

@@ -11,6 +11,7 @@ Run with: pytest -m fuzz
 """
 
 import os
+import re
 import shutil
 import signal
 import time
@@ -19,7 +20,7 @@ import pytest
 
 from test_smoke import (
     ALT, DOWN, UP, LEFT, RIGHT, DELETE, KEY_PRESSED, KEY_RELEASED,
-    BIN, LOG, Session, _nested_session,
+    BIN, LOG, WL, Session, _nested_session,
 )
 
 # Skip the entire module if no host Wayland session.
@@ -33,6 +34,7 @@ GNOME_CALC = shutil.which("gnome-calculator")
 EVINCE = shutil.which("evince")
 MPV = shutil.which("mpv")
 XMSG = shutil.which("xmessage")
+WAYBAR = shutil.which("waybar")
 
 
 def _alive(s):
@@ -45,7 +47,7 @@ def _alive(s):
 def _crash_free(s):
     """Assert no crash signals or assertions in the log."""
     log = s.read_log()
-    for pat in ("Segmentation fault", "Aborted", "Backtrace"):
+    for pat in ("Segmentation fault", "Aborted", "Backtrace", "BACKTRACE"):
         assert pat not in log, f"crash indicator '{pat}' in log"
     # Check for wlroots assertion failures (the pattern is "Assertion `...' failed")
     assert "assertion" not in log.lower() or "assertion failed" not in log.lower(), \
@@ -136,6 +138,65 @@ def test_fuzz_xmessage():
     _run_fuzz(s)
 
 
+# ── layer-shell panel tests ──────────────────────────────────────────
+
+def _kill_session_group(s):
+    """SIGTERM the panel kick spawns for --panel (the sh -c wrapper's group),
+    forcing its layer surfaces down through the normal destroy path."""
+    pid = 0
+    for line in s.read_log().splitlines():
+        m = re.search(r"\[panel\] pid=(\d+)", line)
+        if m:
+            pid = int(m.group(1))
+    assert pid, "no [panel] pid= line in log"
+    os.killpg(pid, signal.SIGTERM)
+    time.sleep(1.0)
+
+
+@pytest.mark.fuzz
+def test_fuzz_waybar_panel():
+    """A --panel waybar should keep kick alive, including when the panel
+    dies and tears its layer surfaces down."""
+    if not WAYBAR:
+        pytest.skip("waybar not installed")
+    s = _nested_session(f"{WL} '#ff0000'", extra_args=("--panel", WAYBAR))
+    try:
+        s.wait_for(r"\[diag\] map app=\d", timeout=10.0)
+        s.wait_for(r"\[panel\] pid=\d+", timeout=10.0)
+        _alive(s)
+
+        # A few cycles (exercises matching actions with a panel attached).
+        for _ in range(3):
+            s.mods(ALT)
+            s.tap(DOWN)
+            time.sleep(0.3)
+        s.mods(0)
+        _alive(s)
+
+        # Hold Alt to check overlay renders.
+        s.mods(ALT)
+        time.sleep(0.5)
+        s.mods(0)
+        _alive(s)
+
+        # Kill the panel, then re-cycle: layer-surface teardown must not
+        # crash the compositor.
+        _kill_session_group(s)
+        s.mods(ALT)
+        s.tap(DOWN)
+        time.sleep(0.5)
+        s.mods(0)
+        _alive(s)
+
+        # Close the tab, then check the whole session was crash-free.
+        s.chord(ALT, DELETE)
+        time.sleep(1.0)
+        _alive(s)
+        _crash_free(s)
+    finally:
+        s.close()
+
+
 # ── multi-tab tests ─────────────────────────────────────────────────
 
 @pytest.mark.fuzz