When linking a page to include it into an other, it's content is erased

Step to reproduce :

• Create Main.Accueil page
• Add a title and a content to it
• Go in Main.WebHome
• Include Main.Acceuil in using the zone macro
• Go in the Main.Acceuil page and edit (inline mode)
• Content is empty
• Go in wiki mode
• Content is empty

Expected result :

• The existing content should not be erased since some other script / code etc... may use them