From e1cd42dcaac407f6bb21d70aea5f113583165c99 Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Thu, 15 Jan 2026 14:26:15 +0100
Subject: [PATCH] xwayland/ci: Enforce various code style checks

Make sure the code change does not contain tab characters nor stray
newlines.

This is contributed by Peter Hutterer, adapted from the libinput similar
CI check.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/2121>
(cherry picked from commit 9c31b4ad8faa6f36ae08a18d008303d07d274e1a)
---
 .gitlab-ci.yml                 |   7 ++
 .gitlab-ci/whitespace-check.py | 133 +++++++++++++++++++++++++++++++++
 2 files changed, 140 insertions(+)
 create mode 100755 .gitlab-ci/whitespace-check.py

diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index c1510da1d..22aadf97c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -334,6 +334,13 @@ check-commits:
       junit: results.xml
   allow_failure: true
 
+check-whitespace:
+  extends:
+    - .fdo.ci-fairy
+  stage: test
+  script:
+    - .gitlab-ci/whitespace-check.py $(git ls-files hw/xwayland)
+
 #
 # Workflow rules needed due to:
 # https://gitlab.freedesktop.org/freedesktop/freedesktop/-/issues/438
diff --git a/.gitlab-ci/whitespace-check.py b/.gitlab-ci/whitespace-check.py
new file mode 100755
index 000000000..ca6745ab2
--- /dev/null
+++ b/.gitlab-ci/whitespace-check.py
@@ -0,0 +1,133 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: MIT
+
+from pathlib import Path
+from dataclasses import dataclass
+
+import argparse
+import itertools
+import os
+import re
+import sys
+
+
+@dataclass
+class WhitespaceError:
+    message: str
+    lineno: int
+    nlines: int = 1
+    column: None | int = None
+    ncolumns: int = 1
+
+
+def test_tab_indent(lines: list[str]) -> list[WhitespaceError]:
+    errors = []
+    for idx, l in enumerate(lines):
+        if re.match("^\t+.*", l):
+            errors.append(
+                WhitespaceError(
+                    "Tab indent", idx, ncolumns=2
+                )
+            )
+    return errors
+
+
+def test_duplicate_empty_lines(lines: list[str]) -> list[WhitespaceError]:
+    errors = []
+    for idx, (l1, l2) in enumerate(itertools.pairwise(lines)):
+        if not l1 and not l2:
+            errors.append(WhitespaceError("Duplicated empty lines", idx, nlines=2))
+    return errors
+
+
+def test_tab_after_space(lines: list[str]) -> list[WhitespaceError]:
+    errors = []
+    for idx, l in enumerate(lines):
+        index = l.find(" \t")
+        if index > -1:
+            errors.append(
+                WhitespaceError(
+                    "Tab after space", idx, nlines=index, column=index, ncolumns=2
+                )
+            )
+    return errors
+
+
+def test_trailing_whitespace(lines: list[str]) -> list[WhitespaceError]:
+    errors = []
+    for idx, l in enumerate(lines):
+        if l.rstrip() != l:
+            errors.append(WhitespaceError("Trailing whitespace", idx))
+    return errors
+
+
+def test_empty_line_between_braces(lines: list[str]) -> list[WhitespaceError]:
+    errors = []
+    for idx in range(len(lines) - 3):
+        l1 = lines[idx]
+        l2 = lines[idx + 1]
+        l3 = lines[idx + 2]
+        if l1.strip() == "}" and l3.strip() == "}" and l2.strip() == "":
+            errors.append(WhitespaceError("Empty line between closing braces", idx + 1))
+    return errors
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Whitespace checker script")
+    parser.add_argument(
+        "files",
+        metavar="FILES",
+        type=Path,
+        nargs="+",
+        help="The files to check",
+    )
+
+    args = parser.parse_args()
+
+    have_errors: bool = False
+
+    if os.isatty(sys.stderr.fileno()):
+        red = "\x1b[0;31m"
+        reset = "\x1b[0m"
+    else:
+        red = ""
+        reset = ""
+
+    for file in args.files:
+        lines = [l.rstrip("\n") for l in file.open().readlines()]
+
+        errors = []
+        errors.extend(test_tab_indent(lines))
+        errors.extend(test_tab_after_space(lines))
+        errors.extend(test_trailing_whitespace(lines))
+        if any(file.name.endswith(suffix) for suffix in [".c", ".h"]):
+            if not file.parts[0] == "include":
+                errors.extend(test_duplicate_empty_lines(lines))
+                errors.extend(test_empty_line_between_braces(lines))
+
+        for e in errors:
+            print(f"{red}ERROR: {e.message} in {file}:{reset}", file=sys.stderr)
+            print(f"{'-' * 72}", file=sys.stderr)
+            lineno = max(0, e.lineno - 5)
+            for idx, l in enumerate(lines[lineno : lineno + 10]):
+                if e.lineno <= lineno + idx < e.lineno + e.nlines:
+                    prefix = "->"
+                    hl = red
+                    nohl = reset
+                else:
+                    prefix = "  "
+                    hl = ""
+                    nohl = ""
+                print(f"{hl}{lineno + idx:3d}: {prefix} {l.rstrip()}{nohl}")
+
+            print(f"{'-' * 72}", file=sys.stderr)
+
+        if errors:
+            have_errors = True
+
+    if have_errors:
+        sys.exit(1)
+
+
+if __name__ == "__main__":
+    main()