Issue #4969: The mimetypes module now reads the MIME database from

the registry under Windows.  Patch by Gabriel Genellina.

Lib/mimetypes.py

@@ -18,13 +18,19 @@ types_map -- dictionary mapping suffixes to types
 
 Functions:
 
-init([files]) -- parse a list of files, default knownfiles
+init([files]) -- parse a list of files, default knownfiles (on Windows, the
+  default values are taken from the registry)
 read_mime_types(file) -- parse one file, return a dictionary or None
 """
 
 import os
+import sys
 import posixpath
 import urllib
+try:
+    import _winreg
+except ImportError:
+    _winreg = None
 
 __all__ = [
     "guess_type","guess_extension","guess_all_extensions",
@@ -220,6 +226,52 @@ class MimeTypes:
             for suff in suffixes:
                 self.add_type(type, '.' + suff, strict)
 
+    def read_windows_registry(self, strict=True):
+        """
+        Load the MIME types database from Windows registry.
+
+        If strict is true, information will be added to
+        list of standard types, else to the list of non-standard
+        types.
+        """
+
+        # Windows only
+        if not _winreg:
+            return
+
+        def enum_types(mimedb):
+            i = 0
+            while True:
+                try:
+                    ctype = _winreg.EnumKey(mimedb, i)
+                except EnvironmentError:
+                    break
+                try:
+                    ctype = ctype.encode(default_encoding) # omit in 3.x!
+                except UnicodeEncodeError:
+                    pass
+                else:
+                    yield ctype
+                i += 1
+
+        default_encoding = sys.getdefaultencoding()
+        with _winreg.OpenKey(_winreg.HKEY_CLASSES_ROOT,
+                             r'MIME\Database\Content Type') as mimedb:
+            for ctype in enum_types(mimedb):
+                with _winreg.OpenKey(mimedb, ctype) as key:
+                    try:
+                        suffix, datatype = _winreg.QueryValueEx(key, 'Extension')
+                    except EnvironmentError:
+                        continue
+                    if datatype != _winreg.REG_SZ:
+                        continue
+                    try:
+                        suffix = suffix.encode(default_encoding) # omit in 3.x!
+                    except UnicodeEncodeError:
+                        continue
+                    self.add_type(ctype, suffix, strict)
+
+
 def guess_type(url, strict=True):
     """Guess the type of a file based on its URL.
 
@@ -299,6 +351,8 @@ def init(files=None):
     inited = True    # so that MimeTypes.__init__() doesn't call us again
     db = MimeTypes()
     if files is None:
+        if _winreg:
+            db.read_windows_registry()
         files = knownfiles
     for file in files:
         if os.path.isfile(file):