lib/axlsx/workbook/worksheet/cell.rb in axlsx-1.1.4 vs lib/axlsx/workbook/worksheet/cell.rb in axlsx-1.1.5

@@ -286,16 +286,18 @@
     # @param [Integer] r_index The row index for the cell
     # @param [Integer] c_index The cell index in the row.
     # @param [String] str The string index the cell content will be appended to. Defaults to empty string.
     # @return [String] xml text for the cell
     def to_xml_string(r_index, c_index, str = '')
-      return str if @value.nil?
       str << '<c r="' << Axlsx::cell_r(c_index, r_index) << '" s="' << @style.to_s << '" '
+      return str << '/>' if @value.nil?
+
       case @type
+
       when :string
         #parse formula
         if @value.start_with?('=')
-          str  << 't="str"><f>' << @value.to_s.gsub('=', '') << '</f>'
+          str  << 't="str"><f>' << @value.to_s.sub('=', '') << '</f>'
         else
           #parse shared
           if @ssti
             str << 't="s"><v>' << @ssti.to_s << '</v>'
           else