Fix incorrect mtime comparison in distutils (#11933).

This is a regression introduced in 9211a5d7d0b4, when uses of ST_MTIME
constants were changed to uses of st_mtime attributes.  As diagnosed in
the bug report, this change is not merely stylistic: st_mtime is a
float but ST_MTIME’s resolution is rounded to the seconds, so there was
a mismatch between the values seen by file_util and dep_util which
caused an sdist to be unnecessarily created a second time on an ext4
filesystem.

This patch has been tested by John S. Gruber, who reported the bug.
As this is a simple code revert, I think it’s okay to commit without a
unit test.

diff --git a/Lib/distutils/dep_util.py b/Lib/distutils/dep_util.py
index 4e40df6899b91849b23b8a468b76b4bd766b4d66..2b759056ea8b2a0042355d715d984c496dae54a6 100644 (file)
--- a/Lib/distutils/dep_util.py
+++ b/Lib/distutils/dep_util.py
@@ -7,6 +7,7 @@ timestamp dependency analysis."""
 __revision__ = "$Id$"
 
 import os
+from stat import ST_MTIME
 from distutils.errors import DistutilsFileError
 
 def newer(source, target):
@@ -27,7 +28,7 @@ def newer(source, target):
     if not os.path.exists(target):
         return True
 
-    return os.stat(source).st_mtime > os.stat(target).st_mtime
+    return os.stat(source)[ST_MTIME] > os.stat(target)[ST_MTIME]
 
 def newer_pairwise(sources, targets):
     """Walk two filename lists in parallel, testing if each source is newer
@@ -71,7 +72,7 @@ def newer_group(sources, target, missing='error'):
     # is more recent than 'target', then 'target' is out-of-date and
     # we can immediately return true.  If we fall through to the end
     # of the loop, then 'target' is up-to-date and we return false.
-    target_mtime = os.stat(target).st_mtime
+    target_mtime = os.stat(target)[ST_MTIME]
 
     for source in sources:
         if not os.path.exists(source):
@@ -82,7 +83,7 @@ def newer_group(sources, target, missing='error'):
             elif missing == 'newer':    # missing source means target is
                 return True             #  out-of-date
 
-        if os.stat(source).st_mtime > target_mtime:
+        if os.stat(source)[ST_MTIME] > target_mtime:
             return True
 
     return False

diff --git a/Misc/ACKS b/Misc/ACKS
index ff0a29a18da425344c56b03463c98f30c14f4d41..a04b63718d43881e6cfb02f49f2c6ff1e80b38d0 100644 (file)
--- a/Misc/ACKS
+++ b/Misc/ACKS
@@ -309,6 +309,7 @@ Hans de Graaff
 Eddy De Greef
 Duncan Grisby
 Fabian Groffen
+John S. Gruber
 Dag Gruneau
 Filip Gruszczyński
 Michael Guravage

diff --git a/Misc/NEWS b/Misc/NEWS
index 01660d568116f7e0b91628b5989e9fa3ec9d1a05..e824332157394975a041b4f141dc55e4cd2bbdec 100644 (file)
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -37,6 +37,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #11933: Fix incorrect mtime comparison in distutils.
+
 - Issues #11104, #8688: Fix the behavior of distutils' sdist command with
   manually-maintained MANIFEST files.