Handle macOS filesystem sometimes setting lower digits to zero.

test cases/common/14 configure file/check_file.py

@@ -3,6 +3,16 @@
 import os
 import sys
 
+def permit_osx_workaround(m1,  m2):
+    import platform
+    if platform.system().lower() != 'darwin':
+        return False
+    if m2 % 10000 != 0:
+        return False
+    if m1//10000 != m2//10000:
+        return False
+    return True
+
 if len(sys.argv) == 2:
     assert(os.path.exists(sys.argv[1]))
 elif len(sys.argv) == 3:
@@ -12,7 +22,11 @@ elif len(sys.argv) == 3:
     m2 = os.stat(f2).st_mtime_ns
     # Compare only os.stat()
     if m1 != m2:
-        raise RuntimeError(f'mtime of {f1!r} () != mtime of {m1!r} ()')
+        # Under macOS the lower four digits sometimes get assigned
+        # zero, even though shutil.copy2 should preserve metadata.
+        # Just have to accept it, I guess.
+        if not permit_osx_workaround(m1, m2):
+            raise RuntimeError(f'mtime of {f1!r} ({m1!r}) != mtime of {f2!r} ({m2!r})')
     import filecmp
     if not filecmp.cmp(f1, f2):
         raise RuntimeError(f'{f1!r} != {f2!r}')