Parsing headerFotter block of test sheet correctly

include/xlnt/styles/font.hpp

@@ -242,7 +242,10 @@ public:
     /// <summary>
     /// Returns true if left is not exactly equal to right.
     /// </summary>
-    bool operator!=(const font &other) const;
+    bool operator!=(const font &other) const
+    {
+        return !operator==(other);
+    }
 
 private:
     friend class style;

source/detail/header_footer/header_footer_code.cpp

@@ -360,6 +360,11 @@ std::array<xlnt::optional<xlnt::rich_text>, 3> decode_header_footer(const std::s
 
             case hf_code::text_single_underline:
                 {
+                    if (!current_run.second.is_set())
+                    {
+                        current_run.second = xlnt::font();
+                    }
+                    current_run.second.get().underline(font::underline_style::single);
                     break;
                 }
 
@@ -533,7 +538,23 @@ std::string encode_header_footer(const rich_text &t, header_footer::location whe
                 ss << run.second.get().size();
                 encoded.append(ss.str());
             }
-
+            if (run.second.get().underlined())
+            {
+                switch (run.second.get().underline()) 
+                {
+                case font::underline_style::single:
+                case font::underline_style::single_accounting:
+                    encoded.append("&U");
+                    break;
+                case font::underline_style::double_:
+                case font::underline_style::double_accounting:
+                    encoded.append("&E");
+                    break;
+                default:
+                case font::underline_style::none:
+                    break;
+                }
+            }
             if (run.second.get().has_color())
             {
                 encoded.push_back('&');

source/styles/font.cpp

@@ -29,8 +29,6 @@
 namespace xlnt {
 
 font::font()
-    : name_("Calibri"),
-      size_(12.0)
 {
 }
 
@@ -155,9 +153,13 @@ font &font::name(const std::string &name)
 }
 
 std::string font::name() const
+{
+    if (name_.is_set())
     {
         return name_.get();
     }
+    return "Calibri";
+}
 
 bool font::has_color() const
 {