[Boost-commit] svn:boost r79481 - in trunk/libs/filesystem: doc src test

Subject: [Boost-commit] svn:boost r79481 - in trunk/libs/filesystem: doc src test
From: bdawes_at_[hidden]
Date: 2012-07-13 15:43:34

Author: bemandawes
Date: 2012-07-13 15:43:33 EDT (Fri, 13 Jul 2012)
New Revision: 79481
URL: http://svn.boost.org/trac/boost/changeset/79481

Log:
Fix a Linux fchmodat problem affecting symlink permissions reported during discussion of 6659. Patch supplied by Duncan Exon Smith. Does not fix the original problem.
Text files modified: 
   trunk/libs/filesystem/doc/release_history.html |     4 +++-                                    
   trunk/libs/filesystem/src/operations.cpp       |    11 ++++++++++-                             
   trunk/libs/filesystem/test/operations_test.cpp |    17 ++++++++++++++++-                       
   3 files changed, 29 insertions(+), 3 deletions(-)

Modified: trunk/libs/filesystem/doc/release_history.html
==============================================================================
--- trunk/libs/filesystem/doc/release_history.html	(original)
+++ trunk/libs/filesystem/doc/release_history.html	2012-07-13 15:43:33 EDT (Fri, 13 Jul 2012)
@@ -47,6 +47,8 @@
   <li>Add range_begin() and range_end() non-member functions for directory_iterator and 
   recursive_directory_iterator so that 
   <a href="http://www.boost.org/libs/foreach/">BOOST_FOREACH</a> works.</li>
+  <li>Fix a Linux fchmodat problem affecting symlink permissions reported during 
+  discussion of #6659.</li>
 </ul>
 
 <h2>1.50.0</h2>
@@ -176,7 +178,7 @@
 </ul>
 <hr>
 <p>Revised
-<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->12 July, 2012<!--webbot bot="Timestamp" endspan i-checksum="21089" --></p>
+<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->13 July, 2012<!--webbot bot="Timestamp" endspan i-checksum="21091" --></p>
 <p>© Copyright Beman Dawes, 2011</p>
 <p> Use, modification, and distribution are subject to the Boost Software 
 License, Version 1.0. See <a href="http://www.boost.org/LICENSE_1_0.txt">

Modified: trunk/libs/filesystem/src/operations.cpp
==============================================================================
--- trunk/libs/filesystem/src/operations.cpp	(original)
+++ trunk/libs/filesystem/src/operations.cpp	2012-07-13 15:43:33 EDT (Fri, 13 Jul 2012)
@@ -1396,8 +1396,17 @@
       prms = current_status.permissions() & ~prms;
 
     // Mac OS X Lion and some other platforms don't support fchmodat()  
+    // Linux does not support permissions on symbolic links and has no plans to
+    // support them in the future.  The chmod() code is thus more practical,
+    // rather than always hitting ENOTSUP when sending in AT_SYMLINK_NO_FOLLOW.
+    //  - See the 3rd paragraph of
+    // "Symbolic link ownership, permissions, and timestamps" at:
+    //   "http://man7.org/linux/man-pages/man7/symlink.7.html"
+    //  - See the fchmodat() Linux man page:
+    //   "http://man7.org/linux/man-pages/man2/fchmodat.2.html"
 #   if defined(AT_FDCWD) && defined(AT_SYMLINK_NOFOLLOW) \
-      && (!defined(__SUNPRO_CC) || __SUNPRO_CC > 0x5100)
+      && (!defined(__SUNPRO_CC) || __SUNPRO_CC > 0x5100) \
+      && !(defined(linux) || defined(__linux) || defined(__linux__))
       if (::fchmodat(AT_FDCWD, p.c_str(), mode_cast(prms),
            !(prms & symlink_perms) ? 0 : AT_SYMLINK_NOFOLLOW))
 #   else  // fallback if fchmodat() not supported

Modified: trunk/libs/filesystem/test/operations_test.cpp
==============================================================================
--- trunk/libs/filesystem/test/operations_test.cpp	(original)
+++ trunk/libs/filesystem/test/operations_test.cpp	2012-07-13 15:43:33 EDT (Fri, 13 Jul 2012)
@@ -115,7 +115,7 @@
 
   unsigned short language_id;  // 0 except for Windows
 
-  const char* temp_dir_name = "v3_operations_test";
+  const char* temp_dir_name = "operations_test";
 
   void create_file(const fs::path & ph, const std::string & contents = std::string())
   {
@@ -848,6 +848,21 @@
       for (fs::directory_iterator itr(dir); itr != fs::directory_iterator(); ++itr)
         if (itr->path().filename() == fs::path("permissions.txt"))
           BOOST_TEST(itr->status().permissions() == fs::owner_all);
+
+      if (create_symlink_ok)  // only if symlinks supported
+      {
+        BOOST_TEST(fs::status(p).permissions() == fs::owner_all);
+        fs::path p2(dir / "permissions-symlink.txt");
+        fs::create_symlink(p, p2);
+        cout << std::oct; 
+        cout << "   status(p).permissions() "  << fs::status(p).permissions() << endl;
+        cout << "  status(p2).permissions() "  << fs::status(p).permissions() << endl;
+        fs::permissions(p2, fs::add_perms | fs::others_read);
+        cout << "   status(p).permissions(): " << fs::status(p).permissions() << endl; 
+        cout << "  status(p2).permissions(): " << fs::status(p2).permissions() << endl;
+        cout << std::dec;
+      }
+
     }
     else // Windows
     {