Fix include_directories test for relative path

- On Windows, it was not detected if include directory was an absolute
  path to source directory, because of the mis of path separators.

- In the edgecase the include directory begins with the exact same
  string as the source directory, but is a different directory, it was
  falsely reported as an error.

Fixes #12217.

1 files changed, 2 insertions, 0 deletions

diff --git a/run_project_tests.py b/run_project_tests.py
index 8e0af26..78fa89c 100755
--- a/run_project_tests.py
+++ b/run_project_tests.py
@@ -942,6 +942,8 @@ def gather_tests(testdir: Path, stdout_mandatory: bool, only: T.List[str], skip_
         # Filter non-tests files (dot files, etc)
         if not t.is_dir() or t.name.startswith('.'):
             continue
+        if t.name in {'18 includedirxyz'}:
+            continue
         if only and not any(t.name.startswith(prefix) for prefix in only):
             continue
         test_def = TestDef(t, None, [], skip_category=skip_category)