Fix #19834: merge with 3.3.

1 files changed, 30 insertions, 4 deletions

diff --git a/Lib/genericpath.py b/Lib/genericpath.py
index 340c00494d..ca4a5108fd 100644
--- a/Lib/genericpath.py
+++ b/Lib/genericpath.py
@@ -7,7 +7,8 @@ import os
 import stat
 
 __all__ = ['commonprefix', 'exists', 'getatime', 'getctime', 'getmtime',
-           'getsize', 'isdir', 'isfile']
+           'getsize', 'isdir', 'isfile', 'samefile', 'sameopenfile',
+           'samestat']
 
 
 # Does a path exist?
@@ -16,7 +17,7 @@ def exists(path):
     """Test whether a path exists.  Returns False for broken symbolic links"""
     try:
         os.stat(path)
-    except os.error:
+    except OSError:
         return False
     return True
 
@@ -27,7 +28,7 @@ def isfile(path):
     """Test whether a path is a regular file"""
     try:
         st = os.stat(path)
-    except os.error:
+    except OSError:
         return False
     return stat.S_ISREG(st.st_mode)
 
@@ -39,7 +40,7 @@ def isdir(s):
     """Return true if the pathname refers to an existing directory."""
     try:
         st = os.stat(s)
-    except os.error:
+    except OSError:
         return False
     return stat.S_ISDIR(st.st_mode)
 
@@ -75,6 +76,31 @@ def commonprefix(m):
             return s1[:i]
     return s1
 
+# Are two stat buffers (obtained from stat, fstat or lstat)
+# describing the same file?
+def samestat(s1, s2):
+    """Test whether two stat buffers reference the same file"""
+    return (s1.st_ino == s2.st_ino and
+            s1.st_dev == s2.st_dev)
+
+
+# Are two filenames really pointing to the same file?
+def samefile(f1, f2):
+    """Test whether two pathnames reference the same actual file"""
+    s1 = os.stat(f1)
+    s2 = os.stat(f2)
+    return samestat(s1, s2)
+
+
+# Are two open files really referencing the same file?
+# (Not necessarily the same file descriptor!)
+def sameopenfile(fp1, fp2):
+    """Test whether two open file objects reference the same file"""
+    s1 = os.fstat(fp1)
+    s2 = os.fstat(fp2)
+    return samestat(s1, s2)
+
+
 # Split a path in root and extension.
 # The extension is everything starting at the last dot in the last
 # pathname component; the root is everything before that.