changeset 26493:13272104bb07

util: use tuple accessor to get accurate st_mtime value (issue4836) Because st.st_mtime is computed as 'sec + 1e-9 * nsec' and double is too narrow to represent nanoseconds, int(st.st_mtime) can be 'sec + 1'. Therefore, that value could be different from the one got by osutils.listdir(). This patch fixes the problem by accessing to raw st_mtime by tuple index. It catches TypeError to fall back to st.st_mtime because our osutil.stat does not support tuple index. In dirstate.normal(), 'st' is always a Python stat, but in dirstate.status(), it can be either a Python stat or an osutil.stat. Thanks to vgatien-baron@janestreet.com for finding the root cause of this subtle problem.
author Yuya Nishihara <yuya@tcha.org>
date Sun, 04 Oct 2015 22:35:36 +0900
parents 3a0bb61371c5
children 832f40d2af53
files mercurial/util.py
diffstat 1 files changed, 13 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/mercurial/util.py	Sun Oct 04 22:25:29 2015 +0900
+++ b/mercurial/util.py	Sun Oct 04 22:35:36 2015 +0900
@@ -19,6 +19,7 @@
 import errno, shutil, sys, tempfile, traceback
 import re as remod
 import os, time, datetime, calendar, textwrap, signal, collections
+import stat
 import imp, socket, urllib
 import gc
 import bz2
@@ -953,7 +954,18 @@
         return os.stat(fp.name)
 
 def statmtimesec(st):
-    return int(st.st_mtime)
+    """Get mtime as integer of seconds
+
+    'int(st.st_mtime)' cannot be used because st.st_mtime is computed as
+    'sec + 1e-9 * nsec' and double-precision floating-point type is too narrow
+    to represent nanoseconds. If 'nsec' is close to 1 sec, 'int(st.st_mtime)'
+    can be 'sec + 1'. (issue4836)
+    """
+    try:
+        return st[stat.ST_MTIME]
+    except TypeError:
+        # osutil.stat doesn't allow index access and its st_mtime is int
+        return st.st_mtime
 
 # File system features