Collection.update() delete&recreate the template instance instead of just rerender it

[acemtp]

Collection.update() delete&recreate the template instance instead of just rerender it.

To reproduce this bug, follow the instruction (don't pay attention to the repo name, there's no constant in the code):

git clone git://github.com/acemtp/meteor-constant-bug.git
cd meteor-constant-bug/
./meteor

Open the browser console, you'll see that when you click the first time on the button, the template is destroyed and created again. if you click a second time, it's not destroyed/created anymore, just rerendered (as expected).

About the created(), the doc says that "This callback is called when an invocation of myTemplate represents a new occurrence of the template and not a re-rendering of an existing template instance."

In the example, it's a re-rendering of an existing template instance.

The very strange thing is that if you remove the {{#if blockLoading}} and just keep the {{>blocks}} then it works as expected in the doc so it seems to be related to the reactive session in blockLoading helper.

As @avital and @dgreensp said in https://groups.google.com/forum/?fromgroups=#!topic/meteor-talk/LKeoSkYqrYE

It seems to be a bug so I fill this issue :-)

[dgreensp]

Fixed on devel. It was a logic bug in the automatic labeling of templates for matching purposes.

Thanks for the great small reproduction. It allowed me to track down the problem, and I used it as the basis for a unit test.