bpo-31202: Preserve case of literal parts in Path.glob() on Windows. (GH-16860)

Lib/pathlib.py

@@ -187,6 +187,9 @@ class _WindowsFlavour(_Flavour):
     def casefold_parts(self, parts):
         return [p.lower() for p in parts]
 
+    def compile_pattern(self, pattern):
+        return re.compile(fnmatch.translate(pattern), re.IGNORECASE).fullmatch
+
     def resolve(self, path, strict=False):
         s = str(path)
         if not s:
@@ -309,6 +312,9 @@ class _PosixFlavour(_Flavour):
     def casefold_parts(self, parts):
         return parts
 
+    def compile_pattern(self, pattern):
+        return re.compile(fnmatch.translate(pattern)).fullmatch
+
     def resolve(self, path, strict=False):
         sep = self.sep
         accessor = path._accessor
@@ -446,7 +452,7 @@ _normal_accessor = _NormalAccessor()
 # Globbing helpers
 #
 
-def _make_selector(pattern_parts):
+def _make_selector(pattern_parts, flavour):
     pat = pattern_parts[0]
     child_parts = pattern_parts[1:]
     if pat == '**':
@@ -457,7 +463,7 @@ def _make_selector(pattern_parts):
         cls = _WildcardSelector
     else:
         cls = _PreciseSelector
-    return cls(pat, child_parts)
+    return cls(pat, child_parts, flavour)
 
 if hasattr(functools, "lru_cache"):
     _make_selector = functools.lru_cache()(_make_selector)
@@ -467,10 +473,10 @@ class _Selector:
     """A selector matches a specific glob pattern part against the children
     of a given path."""
 
-    def __init__(self, child_parts):
+    def __init__(self, child_parts, flavour):
         self.child_parts = child_parts
         if child_parts:
-            self.successor = _make_selector(child_parts)
+            self.successor = _make_selector(child_parts, flavour)
             self.dironly = True
         else:
             self.successor = _TerminatingSelector()
@@ -496,9 +502,9 @@ class _TerminatingSelector:
 
 class _PreciseSelector(_Selector):
 
-    def __init__(self, name, child_parts):
+    def __init__(self, name, child_parts, flavour):
         self.name = name
-        _Selector.__init__(self, child_parts)
+        _Selector.__init__(self, child_parts, flavour)
 
     def _select_from(self, parent_path, is_dir, exists, scandir):
         try:
@@ -512,13 +518,12 @@ class _PreciseSelector(_Selector):
 
 class _WildcardSelector(_Selector):
 
-    def __init__(self, pat, child_parts):
-        self.pat = re.compile(fnmatch.translate(pat))
-        _Selector.__init__(self, child_parts)
+    def __init__(self, pat, child_parts, flavour):
+        self.match = flavour.compile_pattern(pat)
+        _Selector.__init__(self, child_parts, flavour)
 
     def _select_from(self, parent_path, is_dir, exists, scandir):
         try:
-            cf = parent_path._flavour.casefold
             entries = list(scandir(parent_path))
             for entry in entries:
                 entry_is_dir = False
@@ -529,8 +534,7 @@ class _WildcardSelector(_Selector):
                         raise
                 if not self.dironly or entry_is_dir:
                     name = entry.name
-                    casefolded = cf(name)
-                    if self.pat.match(casefolded):
+                    if self.match(name):
                         path = parent_path._make_child_relpath(name)
                         for p in self.successor._select_from(path, is_dir, exists, scandir):
                             yield p
@@ -541,8 +545,8 @@ class _WildcardSelector(_Selector):
 
 class _RecursiveWildcardSelector(_Selector):
 
-    def __init__(self, pat, child_parts):
-        _Selector.__init__(self, child_parts)
+    def __init__(self, pat, child_parts, flavour):
+        _Selector.__init__(self, child_parts, flavour)
 
     def _iterate_directories(self, parent_path, is_dir, scandir):
         yield parent_path
@@ -1118,11 +1122,10 @@ class Path(PurePath):
         """
         if not pattern:
             raise ValueError("Unacceptable pattern: {!r}".format(pattern))
-        pattern = self._flavour.casefold(pattern)
         drv, root, pattern_parts = self._flavour.parse_parts((pattern,))
         if drv or root:
             raise NotImplementedError("Non-relative patterns are unsupported")
-        selector = _make_selector(tuple(pattern_parts))
+        selector = _make_selector(tuple(pattern_parts), self._flavour)
         for p in selector.select_from(self):
             yield p
 
@@ -1131,11 +1134,10 @@ class Path(PurePath):
         directories) matching the given relative pattern, anywhere in
         this subtree.
         """
-        pattern = self._flavour.casefold(pattern)
         drv, root, pattern_parts = self._flavour.parse_parts((pattern,))
         if drv or root:
             raise NotImplementedError("Non-relative patterns are unsupported")
-        selector = _make_selector(("**",) + tuple(pattern_parts))
+        selector = _make_selector(("**",) + tuple(pattern_parts), self._flavour)
         for p in selector.select_from(self):
             yield p
 

Lib/test/test_pathlib.py

@@ -2378,11 +2378,15 @@ class WindowsPathTest(_BasePathTest, unittest.TestCase):
         P = self.cls
         p = P(BASE)
         self.assertEqual(set(p.glob("FILEa")), { P(BASE, "fileA") })
+        self.assertEqual(set(p.glob("F*a")), { P(BASE, "fileA") })
+        self.assertEqual(set(map(str, p.glob("FILEa"))), {f"{p}\\FILEa"})
+        self.assertEqual(set(map(str, p.glob("F*a"))), {f"{p}\\fileA"})
 
     def test_rglob(self):
         P = self.cls
         p = P(BASE, "dirC")
         self.assertEqual(set(p.rglob("FILEd")), { P(BASE, "dirC/dirD/fileD") })
+        self.assertEqual(set(map(str, p.rglob("FILEd"))), {f"{p}\\dirD\\FILEd"})
 
     def test_expanduser(self):
         P = self.cls

Misc/NEWS.d/next/Library/2019-10-20-12-04-48.bpo-31202.NfdIus.rst

+The case the result of :func:`pathlib.WindowsPath.glob` matches now the case
+of the pattern for literal parts.