fixes to storage full allocation mode

src/file.cpp

@@ -248,15 +248,15 @@ namespace libtorrent
 		void set_size(size_type s)
 		{
 			size_type pos = tell();
-			seek(1, 0);
+			seek(s);
 			char dummy = 0;
 			read(&dummy, 1);
-			seek(1, 0);
+			seek(s);
 			write(&dummy, 1);
-			seek(pos, 1);
+			seek(pos);
 		}
 
-		size_type seek(size_type offset, int m)
+		size_type seek(size_type offset, int m = 1)
 		{
 			assert(m_open_mode);
 			assert(m_fd != -1);

src/storage.cpp

@@ -309,7 +309,7 @@ namespace libtorrent
 #endif
 			}
 			catch (std::exception&) {}
-			if (size != s->first
+			if ((compact_mode && size != s->first)
 				|| (!compact_mode && size < s->first))
 			{
 				if (error) *error = "filesize mismatch for file '"
@@ -319,7 +319,7 @@ namespace libtorrent
 					+ " bytes";
 				return false;
 			}
-			if (time != s->second
+			if ((compact_mode && time != s->second)
 				|| (!compact_mode && time < s->second))
 			{
 				if (error) *error = "timestamp mismatch for file '"
@@ -1613,22 +1613,42 @@ namespace libtorrent
 				m_unallocated_slots.push_back(i);
 			}
 
-			if (!m_compact_mode && !m_unallocated_slots.empty())
-			{
-				m_state = state_allocating;
-				return false;
-			}
-			else
+			if (m_compact_mode || m_unallocated_slots.empty())
 			{
 				m_state = state_finished;
 				return true;
 			}
 		}
 
-		m_state = state_create_files;
+		m_current_slot = 0;
+		m_state = state_full_check;
 		return false;
 	}
 
+/*
+	state chart:
+
+	check_fastresume()
+
+		|        |
+		|        v
+		|  +------------+
+		|  | full_check |
+		|  +------------+
+		|        |
+		|        v
+		|  +------------+   +--------------+
+		|  | allocating |-->| create_files |
+		|  +------------+   +--------------+
+		|        |                 |
+		|        v                 |
+		|     +----------+         |
+		+---->| finished |<--------+
+				+----------+
+
+*/
+
+
 	// performs the full check and full allocation
 	// (if necessary). returns true if finished and
 	// false if it should be called again
@@ -1654,6 +1674,15 @@ namespace libtorrent
 				return std::make_pair(true, 1.f);
 			}
 
+			if (int(m_unallocated_slots.size()) == m_info.num_pieces()
+				&& !m_fill_mode)
+			{
+				// if there is not a single file on disk, just
+				// create the files
+				m_state = state_create_files;
+				return std::make_pair(false, 1.f);
+			}
+
 			// if we're not in compact mode, make sure the
 			// pieces are spread out and placed at their
 			// final position.
@@ -1682,10 +1711,19 @@ namespace libtorrent
 		{
 			m_storage->initialize(!m_fill_mode && !m_compact_mode);
 
-			m_current_slot = 0;
-			m_state = state_full_check;
-			m_piece_data.resize(int(m_info.piece_length()));
-			return std::make_pair(false, 0.f);
+			if (!m_unallocated_slots.empty())
+			{
+				assert(!m_fill_mode);
+				assert(!m_compact_mode);
+				std::vector<int>().swap(m_unallocated_slots);
+				std::fill(m_slot_to_piece.begin(), m_slot_to_piece.end(), int(unassigned));
+				m_free_slots.resize(m_info.num_pieces());
+				for (int i = 0; i < m_info.num_pieces(); ++i)
+					m_free_slots[i] = i;
+			}
+
+			m_state = state_finished;
+			return std::make_pair(true, 1.f);
 		}
 
 		assert(m_state == state_full_check);
@@ -1697,6 +1735,7 @@ namespace libtorrent
 		try
 		{
 
+			m_piece_data.resize(int(m_info.piece_length()));
 			int piece_size = int(m_info.piece_size(m_current_slot));
 			int num_read = m_storage->read(&m_piece_data[0]
 				, m_current_slot, 0, piece_size);