Preserve whether there is a EOL at EOF when writing the file

src/core/Buffer.cc

@@ -55,8 +55,11 @@ bool Buffer::load_from_file(const char * filename)
     piece_table = std::make_shared<PieceTable>(m_file_buffer, m_file_buffer_size);
     for (auto it = text_loader.begin(); it != text_loader.end(); it++)
     {
+        auto next = it;
+        next++;
+        bool eol = next != text_loader.end();
         /* TODO: correctly calculate n_chars based on current file encoding. */
-        piece_table->append_initial_line_piece(it->first, it->second, it->second);
+        piece_table->append_initial_line_piece(it->first, it->second, it->second, eol);
     }
 
     m_eol_at_eof = text_loader.get_eol_at_eof();
@@ -93,6 +96,7 @@ bool Buffer::write_to_file(const char * filename)
         return false;
     }
 
+    uint32_t bytes_written = 0u;
     for (auto pd = piece_table->start_descriptor->next;
          pd != piece_table->end_descriptor;
          pd = pd->next)
@@ -101,12 +105,22 @@ bool Buffer::write_to_file(const char * filename)
         {
             return false;
         }
+        bytes_written += pd->length;
         if (pd->eol())
         {
             if (!file.write((const uint8_t *)eol_seq, eol_len))
             {
                 return false;
             }
+            bytes_written += eol_len;
+        }
+    }
+
+    if (m_eol_at_eof && bytes_written > 0u)
+    {
+        if (!file.write((const uint8_t *)eol_seq, eol_len))
+        {
+            return false;
         }
     }
 

src/core/PieceTable.cc

@@ -11,14 +11,16 @@ PieceTable::PieceTable(const uint8_t * file_buffer, unsigned long file_buffer_si
     m_piece_descriptor_index = 2u;
 }
 
-void PieceTable::append_initial_line_piece(uint8_t * start, uint32_t length, uint32_t n_chars)
+void PieceTable::append_initial_line_piece(uint8_t * start, uint32_t length, uint32_t n_chars, bool eol)
 {
     PieceDescriptor * pd = add_piece_descriptor();
     pd->prev = end_descriptor->prev;
     pd->next = end_descriptor;
     pd->start = start;
     pd->length = length;
-    pd->n_chars = n_chars | PIECE_DESCRIPTOR_N_CHARS_EOL_FLAG_MASK;
+    pd->n_chars = n_chars;
+    if (eol)
+        pd->n_chars |= PIECE_DESCRIPTOR_N_CHARS_EOL_FLAG_MASK;
     end_descriptor->prev->next = pd;
     end_descriptor->prev = pd;
     m_num_lines++;

src/core/PieceTable.h

@@ -68,7 +68,7 @@ public:
     PieceDescriptor * start_descriptor;
     PieceDescriptor * end_descriptor;
 
-    void append_initial_line_piece(uint8_t * start, uint32_t length, uint32_t n_chars);
+    void append_initial_line_piece(uint8_t * start, uint32_t length, uint32_t n_chars, bool eol);
 
 protected:
     const uint8_t * m_file_buffer;