fixed inconsistency when creating torrents with symlinks

ChangeLog

@@ -26,6 +26,7 @@
 	  incoming connection
 	* added more detailed instrumentation of the disk I/O thread
 
+	* fixed inconsistency when creating torrents with symlinks
 	* properly detect windows version to initialize half-open connection limit
 	* fixed bug in url encoder where $ would not be encoded
 

docs/make_torrent.rst

@@ -58,12 +58,16 @@ add_files
 	::
 	
 		template <class Pred>
-		void add_files(file_storage& fs, boost::filesystem::path const& path, Pred p);
+		void add_files(file_storage& fs, boost::filesystem::path const& path, Pred p
+			, boost::uint32_t flags = 0);
 		template <class Pred>
-		void add_files(file_storage& fs, boost::filesystem::wpath const& path, Pred p);
+		void add_files(file_storage& fs, boost::filesystem::wpath const& path, Pred p
+			, boost::uint32_t flags = 0);
 
-		void add_files(file_storage& fs, boost::filesystem::path const& path);
-		void add_files(file_storage& fs, boost::filesystem::wpath const& path);
+		void add_files(file_storage& fs, boost::filesystem::path const& path
+			, boost::uint32_t flags = 0);
+		void add_files(file_storage& fs, boost::filesystem::wpath const& path
+			, boost::uint32_t flags = 0);
 
 Adds the file specified by ``path`` to the ``file_storage`` object. In case ``path``
 refers to a diretory, files will be added recursively from the directory.
@@ -84,6 +88,9 @@ are traveresed.
 
 The ".." directory is never traversed.
 
+The ``flags`` argument should be the same as the flags passed to the `create_torrent`_
+constructor.
+
 set_piece_hashes()
 ==================
 
@@ -224,7 +231,8 @@ The ``create_torrent`` class has the following synopsis::
 			, symlink = 8
 			, calculate_file_hashes = 16
 		};
-		create_torrent(file_storage& fs, int piece_size = 0, int pad_size_limit = -1, int flags = optimize);
+		create_torrent(file_storage& fs, int piece_size = 0, int pad_size_limit = -1
+			, int flags = optimize);
 		create_torrent(torrent_info const& ti);
 
 		entry generate() const;
@@ -258,7 +266,8 @@ create_torrent()
 			, symlink = 8
 			, calculate_file_hashes = 16
 		};
-		create_torrent(file_storage& fs, int piece_size = 0, int pad_size_limit = -1, int flags = optimize);
+		create_torrent(file_storage& fs, int piece_size = 0, int pad_size_limit = -1
+			, int flags = optimize);
 		create_torrent(torrent_info const& ti);
 
 The ``piece_size`` is the size of each piece in bytes. It must
@@ -300,11 +309,10 @@ modification_time
 	files.
 
 symlink
-	If this flag is defined, files that are symlinks get a symlink attribute
-	set on them. The file data will still be the same, the symlink will always
-	be followed when opening the file, but the file list will include the path
-	of the symlink so that the original directory structure can be reproduced
-	on the downloading side.
+	If this flag is set, files that are symlinks get a symlink attribute
+	set on them and their data will not be included in the torrent. This
+	is useful if you need to reconstruct a file hierarchy which contains
+	symlinks.
 
 calculate_file_hashes
 	If this is set, the `set_piece_hashes()`_ function will, as it calculates

examples/make_torrent.cpp

@@ -77,6 +77,8 @@ void print_usage()
 		"            than bytes will be piece-aligned\n"
 		"-s bytes    specifies a piece size for the torrent\n"
 		"            This has to be a multiple of 16 kiB\n"
+		"-l          Don't follow symlinks, instead encode them as\n"
+		"            links in the torrent file\n"
 		"-o file     specifies the output filename of the torrent file\n"
 		"            If this is not specified, the torrent file is\n"
 		"            printed to the standard out, except on windows\n"
@@ -150,6 +152,9 @@ int main(int argc, char* argv[])
 				case 'f':
 					flags |= create_torrent::calculate_file_hashes;
 					break;
+				case 'l':
+					flags |= create_torrent::symlinks;
+					break;
 				default:
 					print_usage();
 					return 1;
@@ -160,7 +165,7 @@ int main(int argc, char* argv[])
 		file_pool fp;
 		std::string full_path = libtorrent::complete(argv[1]);
 
-		add_files(fs, full_path, file_filter);
+		add_files(fs, full_path, file_filter, flags);
 		if (fs.num_files() == 0)
 		{
 			fputs("no files specified.\n", stderr);

include/libtorrent/create_torrent.hpp

@@ -180,22 +180,32 @@ namespace libtorrent
 
 		template <class Pred>
 		void add_files_impl(file_storage& fs, std::string const& p
-			, std::string const& l, Pred pred)
+			, std::string const& l, Pred pred, boost::uint32_t flags)
 		{
 			std::string f = combine_path(p, l);
 			if (!pred(f)) return;
 			error_code ec;
 			file_status s;
-			stat_file(f, &s, ec);
+			stat_file(f, &s, ec, (flags & create_torrent::symlinks) ? dont_follow_links : 0);
 			if (ec) return;
 
-			if (s.mode & file_status::directory)
+			// recurse into directories
+			bool recurse = s.mode & file_status::directory;
+
+			// if the file is not a link or we're following links, and it's a directory
+			// only then should we recurse
+#ifndef TORRENT_WINDOWS
+			if ((s.mode & file_status::link) && (flags & create_torrent::symlinks))
+				recurse = false;
+#endif
+
+			if (recurse)
 			{
 				for (directory i(f, ec); !i.done(); i.next(ec))
 				{
 					std::string leaf = i.file();
 					if (ignore_subdir(leaf)) continue;
-					add_files_impl(fs, p, combine_path(l, leaf), pred);
+					add_files_impl(fs, p, combine_path(l, leaf), pred, flags);
 				}
 			}
 			else
@@ -204,7 +214,8 @@ namespace libtorrent
 				int file_flags = get_file_attributes(f);
 
 				// mask all bits to check if the file is a symlink
-				if (file_flags & file_storage::attribute_symlink) 
+				if ((file_flags & file_storage::attribute_symlink)
+					&& (flags & create_torrent::symlinks)) 
 				{
 					std::string sym_path = get_symlink_path(f);
 					fs.add_file(l, 0, file_flags, s.mtime, sym_path);
@@ -218,14 +229,15 @@ namespace libtorrent
 	}
 
 	template <class Pred>
-	void add_files(file_storage& fs, std::string const& file, Pred p)
+	void add_files(file_storage& fs, std::string const& file, Pred p, boost::uint32_t flags = 0)
 	{
-		detail::add_files_impl(fs, parent_path(complete(file)), filename(file), p);
+		detail::add_files_impl(fs, parent_path(complete(file)), filename(file), p, flags);
 	}
 
-	inline void add_files(file_storage& fs, std::string const& file)
+	inline void add_files(file_storage& fs, std::string const& file, boost::uint32_t flags = 0)
 	{
-		detail::add_files_impl(fs, parent_path(complete(file)), filename(file), detail::default_pred);
+		detail::add_files_impl(fs, parent_path(complete(file)), filename(file)
+			, detail::default_pred, flags);
 	}
 	
 	struct piece_holder
@@ -318,18 +330,20 @@ namespace libtorrent
 	// wstring versions
 
 	template <class Pred>
-	void add_files(file_storage& fs, std::wstring const& wfile, Pred p)
+	void add_files(file_storage& fs, std::wstring const& wfile, Pred p, boost::uint32_t flags = 0)
 	{
 		std::string utf8;
 		wchar_utf8(wfile, utf8);
-		detail::add_files_impl(fs, parent_path(complete(utf8)), filename(utf8), p);
+		detail::add_files_impl(fs, parent_path(complete(utf8))
+			, filename(utf8), p, flags);
 	}
 
-	inline void add_files(file_storage& fs, std::wstring const& wfile)
+	inline void add_files(file_storage& fs, std::wstring const& wfile, boost::uint32_t flags = 0)
 	{
 		std::string utf8;
 		wchar_utf8(wfile, utf8);
-		detail::add_files_impl(fs, parent_path(complete(utf8)), filename(utf8), detail::default_pred);
+		detail::add_files_impl(fs, parent_path(complete(utf8))
+			, filename(utf8), detail::default_pred, flags);
 	}
 	
 	template <class Fun>

include/libtorrent/file.hpp

@@ -104,8 +104,9 @@ namespace libtorrent
 		int mode;
 	};
 
+	enum stat_flags_t { dont_follow_links = 1 };
 	TORRENT_EXPORT void stat_file(std::string const& f, file_status* s
-		, error_code& ec);
+		, error_code& ec, int flags = 0);
 	TORRENT_EXPORT void rename(std::string const& f
 		, std::string const& newf, error_code& ec);
 	TORRENT_EXPORT void create_directories(std::string const& f

src/create_torrent.cpp

@@ -170,6 +170,7 @@ namespace libtorrent
 		, m_merkle_torrent(ti.is_merkle_torrent())
 		, m_include_mtime(false)
 		, m_include_symlinks(false)
+		, m_calculate_file_hashes(false)
 	{
 		TORRENT_ASSERT(ti.is_valid());
 		if (ti.creation_date()) m_creation_date = *ti.creation_date();

src/file.cpp

@@ -126,7 +126,8 @@ BOOST_STATIC_ASSERT((libtorrent::file::no_buffer & libtorrent::file::attribute_m
 
 namespace libtorrent
 {
-	void stat_file(std::string const& inf, file_status* s, error_code& ec)
+	void stat_file(std::string const& inf, file_status* s
+		, error_code& ec, int flags)
 	{
 		ec.clear();
 
@@ -149,7 +150,12 @@ namespace libtorrent
 		}
 #else
 		struct stat ret;
-		if (::stat(f.c_str(), &ret) < 0)
+		int retval;
+		if (flags & dont_follow_links)
+			retval = ::lstat(f.c_str(), &ret);
+		else
+			retval = ::stat(f.c_str(), &ret);
+		if (retval < 0)
 		{
 			ec.assign(errno, boost::system::get_generic_category());
 			return;