Write file to argument given to 'w' command, if present

src/core/EncodedString.h

@@ -83,6 +83,10 @@ public:
     {
         return !(*this == s);
     }
+    std::string to_string() const
+    {
+        return std::string((const char *)&(*m_data)[0], m_size);
+    }
 
 protected:
     Encoding::Type m_encoding;

src/gui/Window.cc

@@ -552,9 +552,22 @@ void Window::handle_command(const EncodedString & command)
 void Window::command_write_file(const CommandParser & cp)
 {
     std::shared_ptr<Buffer> buffer = m_focused_buffer_pane->buffer();
-    if (buffer->filename())
+    std::string path;
+    if (cp.size() >= 2)
     {
-        buffer->write_to_file(buffer->filename()->c_str());
+        path = cp[1].to_string();
+    }
+    else
+    {
+        auto filename = buffer->filename();
+        if (filename)
+        {
+            path = *filename;
+        }
+    }
+    if (path != "")
+    {
+        buffer->write_to_file(path.c_str());
     }
 }