Dispose layout data for every node removed from the tree

[nick-thompson]

Fix for #6754.

cc @jdm – I believe this is all that's required for the fix, but until I get a better sense of #6813, I'm unsure of the best way to test this.

[highfive]

Thanks for the pull request, and welcome! The Servo team is excited to review your changes, and you should hear from @glennw (or someone else) soon.

[jdm]

Based way to ensure this is doing what we think right now is to add a println! to the dispose method that prints the pointer being disposed, and see what happens before and after this change when disconnecting a node with a child from the document.

[jdm]

-S-awaiting-review +S-needs-code-changes

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Review status: 0 of 1 files reviewed at latest revision, 1 unresolved discussion, all commit checks successful.

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^{components/script/dom/node.rs, line 375 [r1] (raw file):}
This is extraneous now, since traverse_preorder includes the root node.

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Comments from the review on Reviewable.io

[jdm]

Reviewed 1 of 1 files at r1.
Review status: all files reviewed at latest revision, 1 unresolved discussion, all commit checks successful.

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Comments from the review on Reviewable.io

[nick-thompson]

Fixed the extraneous code, tested as you suggested and saw the expected results. My test approach is covered in this paste: http://pastebin.com/LqxLxbT3

Thanks!

[jdm]

@bors-servo: r+
-S-awaiting-review +S-awaiting-merge

Thanks for the patch!

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Reviewed 1 of 1 files at r2.
Review status: all files reviewed at latest revision, all discussions resolved, all commit checks successful.

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Comments from the review on Reviewable.io

[metajack]

@bors-servo r=jdm

[bors-servo]

📌 Commit 072609a has been approved by jdm

[bors-servo]

⌛ Testing commit 072609a with merge 8b71200...

[bors-servo]

☀️ Test successful - android, gonk, linux1, linux2, linux3, mac1, mac2, mac3