diff -up release26-maint/Lib/os.py.orig release26-maint/Lib/os.py
--- release26-maint/Lib/os.py.orig	2008-10-23 04:27:36.000000000 +0300
+++ release26-maint/Lib/os.py	2009-02-20 10:46:44.000000000 +0200
@@ -668,9 +668,11 @@ if _exists("fork"):
             msg = "os.popen2 is deprecated.  Use the subprocess module."
             warnings.warn(msg, DeprecationWarning, stacklevel=2)
 
+            use_shell = isinstance(cmd, str)
+
             import subprocess
             PIPE = subprocess.PIPE
-            p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,
+            p = subprocess.Popen(cmd, shell=use_shell, bufsize=bufsize,
                                  stdin=PIPE, stdout=PIPE, close_fds=True)
             return p.stdin, p.stdout
         __all__.append("popen2")
@@ -687,9 +689,11 @@ if _exists("fork"):
             msg = "os.popen3 is deprecated.  Use the subprocess module."
             warnings.warn(msg, DeprecationWarning, stacklevel=2)
 
+            use_shell = isinstance(cmd, str)
+            
             import subprocess
             PIPE = subprocess.PIPE
-            p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,
+            p = subprocess.Popen(cmd, shell=use_shell, bufsize=bufsize,
                                  stdin=PIPE, stdout=PIPE, stderr=PIPE,
                                  close_fds=True)
             return p.stdin, p.stdout, p.stderr
@@ -707,9 +711,11 @@ if _exists("fork"):
             msg = "os.popen4 is deprecated.  Use the subprocess module."
             warnings.warn(msg, DeprecationWarning, stacklevel=2)
 
+            use_shell = isinstance(cmd, str)
+
             import subprocess
             PIPE = subprocess.PIPE
-            p = subprocess.Popen(cmd, shell=True, bufsize=bufsize,
+            p = subprocess.Popen(cmd, shell=use_shell, bufsize=bufsize,
                                  stdin=PIPE, stdout=PIPE,
                                  stderr=subprocess.STDOUT, close_fds=True)
             return p.stdin, p.stdout