diff -r cb297930d2cf Lib/shutil.py
--- a/Lib/shutil.py	Thu Jan 17 23:36:08 2013 +0100
+++ b/Lib/shutil.py	Thu Jan 17 23:24:15 2013 +0000
@@ -1078,7 +1078,7 @@
 
     # Short circuit. If we're given a full path which matches the mode
     # and it exists, we're done here.
-    if _access_check(cmd, mode):
+    if os.path.isabs(cmd) and _access_check(cmd, mode):
         return cmd
 
     path = (path or os.environ.get("PATH", os.defpath)).split(os.pathsep)
diff -r cb297930d2cf Lib/test/test_shutil.py
--- a/Lib/test/test_shutil.py	Thu Jan 17 23:36:08 2013 +0100
+++ b/Lib/test/test_shutil.py	Thu Jan 17 23:24:15 2013 +0000
@@ -1316,6 +1316,21 @@
             self.assertEqual(rv, os.path.join(tail_dir, self.file))
         finally:
             os.chdir(old_cwd)
+    
+    def test_cwd(self):
+        old_cwd = os.getcwd()
+        base_dir, _ = os.path.split(self.dir)
+        os.chdir(self.dir)
+        try:
+            rv = shutil.which(self.file, path=base_dir)
+            if sys.platform == "win32":
+                # Windows: current directory implicitly on PATH
+                self.assertEqual(rv, os.path.join(os.curdir, self.file))
+            else:
+                # Other platforms: shouldn't match in the current directory.
+                self.assertIsNone(rv)
+        finally:
+            os.chdir(old_cwd)
 
     def test_nonexistent_file(self):
         # Return None when no matching executable file is found on the path.