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Changes between Initial Version and Version 1 of Ticket #23516, comment 3

initial	v1
10	10	you'll see failures in both 1.6 and 1.7.
11	11
12		The problem is that `IfChangedNode` stores what it looked like last time in the context by setting it as `state_frame[self]`. We were only getting the right thing in 1.6 because it was using `ConstantIncludeNode`, which calls `get_template` in its `__init__()`. With a normal `IncludeNode`, which is all there is in 1.7, `get_template` is called in `render()` causing a new `IfChangedNode` object. When the new `IfChangedNode` is looked up in as `state_frame[self]` it's not the same `self`!
	12	The problem is that `IfChangedNode` stores what it looked like last time in the context by setting it as `state_frame[self]`. We were only getting the right thing in 1.6 because it was using `ConstantIncludeNode`, which calls `get_template` in its `__init__()`. With a normal `IncludeNode`, which is all there is in 1.7, `get_template` is called in `render()` causing a new `IfChangedNode` object. When the new `IfChangedNode` is looked up as `state_frame[self]` it's not the same `self`!
13	13
14	14	Now I understand the problem, but I'm still not sure I have a solution. Perhaps `IfChangedNode` could be made to produce the same object rather than a new copy under the right circumstances, or perhaps we should store the previous version to compare to in `state_frame` using something other than `self` as the key.