[patch] Backport of upstream r69481 without "with"

bug256953e.patch (text/plain), 2.00 KB, created by Martin von Gagern on 2009-02-10 11:20:19 UTC

compileall used the ctime of bytecode and source to determine if the bytecode
should be recreated. This created a timing hole. Fixed by just doing what
import does; check the mtime and magic number.

Backport of the core difference from r69481 to the release25-maint branch.
By replacing the with/as with a try/finally, this patch should work for
python 2.4 as well.

2009-02-10 Martin von Gagern

References:
https://bugs.gentoo.org/256953
http://bugs.python.org/issue5128
http://svn.python.org/view?view=rev&rev=69481

Index: Lib/compileall.py
===================================================================
--- Lib/compileall.py	(revision 69204)
+++ Lib/compileall.py	(working copy)
@@ -11,10 +11,11 @@
 See module py_compile for details of the actual byte-compilation.
 
 """
-
 import os
 import sys
 import py_compile
+import struct
+import imp
 
 __all__ = ["compile_dir","compile_path"]
 
@@ -54,11 +55,20 @@
         if os.path.isfile(fullname):
             head, tail = name[:-3], name[-3:]
             if tail == '.py':
-                cfile = fullname + (__debug__ and 'c' or 'o')
-                ftime = os.stat(fullname).st_mtime
-                try: ctime = os.stat(cfile).st_mtime
-                except os.error: ctime = 0
-                if (ctime > ftime) and not force: continue
+                if not force:
+                    try:
+                        mtime = os.stat(fullname).st_mtime
+                        expect = struct.pack('<4sl', imp.get_magic(), mtime)
+                        cfile = fullname + (__debug__ and 'c' or 'o')
+                        chandle = open(cfile, 'rb')
+                        try:
+                            actual = chandle.read(8)
+                        finally:
+                            chandle.close()
+                        if expect == actual:
+                            continue
+                    except IOError:
+                        pass
                 if not quiet:
                     print 'Compiling', fullname, '...'
                 try: