RFR: 8368675: IGV: nodes are wrongly marked as changed in the difference view

[Manuel Hässig]

On Fri, 26 Sep 2025 08:34:34 GMT, Roberto Castañeda Lozano <rcastanedalo at openjdk.org> wrote:

> This changeset refines IGV's node difference analysis to ignore changes in node properties that are derived by IGV, as opposed to generated by HotSpot. Derived properties include the label and color of each node. Ignoring changes in these properties prevents IGV from wrongly marking equal nodes as "changed" (colored in yellow) when showing the difference between two graphs:
> 
> <img width="2323" height="651" alt="before-after" src="https://github.com/user-attachments/assets/ea51c86d-4719-45c0-b615-e6e4b8aec023" />
> 
> **Testing:** tier1 and manual testing on a few graphs.

Thank you very much for fixing this, @robcasloz! I have been seeing this and wondered if that is intentional.

I tested this on my machine and it works a treat! Looks good to me.

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Marked as reviewed by mhaessig (Committer).

PR Review: https://git.openjdk.org/jdk/pull/27515#pullrequestreview-3272075747