fix(release): avoid SIGPIPE when reading patch subject

.github/workflows/auto-release.yml

@@ -233,7 +233,7 @@ jobs:
           TAG="v${CARGO_VERSION}"
 
           # First line, minus the `--patch` token (with surrounding spaces).
-          SUBJECT="$(printf '%s' "$MSG" | head -n 1)"
+          SUBJECT="${MSG%%$'\n'*}"
           DESC="$(printf '%s' "$SUBJECT" \
                    | sed -E 's/[[:space:]]*--patch[[:space:]]*/ /g; s/^[[:space:]]+//; s/[[:space:]]+$//')"
           if [[ -z "$DESC" ]]; then

scripts/test_patch_bullet.py

@@ -0,0 +1,82 @@
+"""Run the actual patch-bullet shell step locally without publication commands."""
+from pathlib import Path
+import subprocess
+import tempfile
+import unittest
+
+ROOT = Path(__file__).resolve().parents[1]
+WORKFLOW = ROOT / ".github/workflows/auto-release.yml"
+SHA = "1234567890abcdef1234567890abcdef12345678ab"
+REPO = "fixture/owned-repository"
+
+
+def compose_script():
+    workflow = WORKFLOW.read_text()
+    marker = "      - name: Compose patch bullet\n"
+    assert workflow.count(marker) == 1
+    step = workflow.split(marker, 1)[1].split("        run: |\n", 1)[1]
+    lines = []
+    for line in step.splitlines():
+        if line and not line.startswith("          "):
+            break
+        lines.append(line[10:])
+    script = "\n".join(lines)
+    assert script.startswith("set -euo pipefail\n")
+    return script
+
+
+class PatchBullet(unittest.TestCase):
+    def check_message(self, message, description):
+        with tempfile.TemporaryDirectory(prefix="coven-patch-bullet-") as directory:
+            root = Path(directory)
+            cargo = root / "src-rust/Cargo.toml"
+            cargo.parent.mkdir()
+            original = b'[workspace.package]\nversion = "1.2.3"\n'
+            cargo.write_bytes(original)
+            output = root / "output"
+            result = subprocess.run(
+                ["/bin/bash", "--noprofile", "--norc", "-c", compose_script()],
+                cwd=root,
+                env={
+                    "PATH": "/usr/bin:/bin", "HOME": directory,
+                    "MSG": message, "SHA": SHA, "REPO": REPO,
+                    "GITHUB_OUTPUT": str(output),
+                },
+                capture_output=True, text=True, timeout=5,
+            )
+            self.assertEqual(result.returncode, 0, result.stderr)
+            bullet = f"- {description} ([`{SHA[:7]}`](https://github.com/{REPO}/commit/{SHA}))"
+            self.assertEqual(output.read_text(), f"tag=v1.2.3\nbullet<<__EOF__\n{bullet}\n__EOF__\n")
+            self.assertEqual(result.stdout, f"Will patch v1.2.3 with:\n  {bullet}\n")
+            self.assertEqual(result.stderr, "")
+            self.assertEqual(cargo.read_bytes(), original)
+            self.assertEqual(sorted(path.name for path in root.iterdir()), ["output", "src-rust"])
+
+    def test_large_bodies_do_not_break_subject_extraction(self):
+        # Each environment value stays below Linux's per-string exec limit.
+        for length in (100_000, 120_000):
+            with self.subTest(body_bytes=length):
+                self.check_message("fix output --patch\n\n" + ("body\n" * (length // 5)), "fix output")
+
+    def test_first_line_and_marker_behavior(self):
+        cases = [
+            ("fix output --patch", "fix output"),
+            ("fix output --patch\n", "fix output"),
+            ("fix output --patch\nbody ignored\n", "fix output"),
+            ("  --patch fix output --patch  \nbody", "fix output"),
+            ("subject without marker\n--patch", "subject without marker"),
+            ("--patch\nbody", "(patch — see commit)"),
+            ("\nbody --patch", "(patch — see commit)"),
+            ("", "(patch — see commit)"),
+        ]
+        for message, expected in cases:
+            with self.subTest(message=message):
+                self.check_message(message, expected)
+
+    def test_subject_is_literal_shell_data(self):
+        subject = "fix $(touch injected) `touch injected2` ; & < > 'quoted' --patch"
+        self.check_message(subject + "\nbody", subject.removesuffix(" --patch"))
+
+
+if __name__ == "__main__":
+    unittest.main()