Block will be placed when you right-click flag on the chest

BTW,there is one another similar issue:If you have Quark installed and enable 'Shift-click to ignore signs' option,the block in hand will be placed when you shift-click the signs on the chest.

What exactly do you mean by "when you right-click flag"?
It´s the flag part, that I can´t get to make sense!

Sry my expression may be not clear enough.
When you right-click a sign/painting/banner/item frame attached to a chest,you will open the chest.But if you right-click the banner/shift-click the sign attached the chest with placeable block in hand,this block will be placed.
Please watch this video

That´s intended behaviour :)

That´s the same as if you shift right-click a chest, then it will place the block you´re holding.

That´s the same as if you shift right-click a chest, then it will place the block you´re holding.

The issue on banner don't need press shift to trigger.It can happen when you only right-click the banner.Is this also an intended behavior? It's enough to affect the gaming experience negatively,every time I open the chest,a block will be placed

Oh I see what you´re saying now!
No that´s indeed not intended.