Fix bug in properties directive. Refs #9585.

- If a property had all empty field for a specific argument then the table would not be built.

Code/Mantid/docs/sphinxext/mantiddoc/directives/properties.py

@@ -65,8 +65,11 @@ class PropertiesDirective(BaseDirective):
             'Name', 'Direction', 'Type', 'Default', 'Description')
         # The width of the columns. Multiply row length by 10 to ensure small
         # properties format correctly.
-        col_sizes = [max(len(row[i] * 10) for row in table_content)
-                     for i in range(len(header_content))]
+        # Added 10 to the length to ensure if table_content is 0 that
+        # the table is still displayed.
+        col_sizes = [max( (len(row[i] * 10) + 10) for row in table_content)
+                for i in range(len(header_content))]
+
         # Use the column widths as a means to formatting columns.
         formatter = ' '.join('{%d:<%d}' % (index,col) for index, col in enumerate(col_sizes))
         # Add whitespace to each column. This depends on the values returned by