BUG: Block Navigation no longer works correctly in v2025.39

[goran-w]

Block Navigation has become "derailed", after exactly this commit (which is included in release v2025.39) : 0d7d9c2

Specifically, it's no longer always highlighting the correct block when navigating - instead it starts offsetting the line-interval more and more when stepping forward through the sequence of change-blocks. It gets worse the more change-blocks there are in a diff.

See this example screenshot, which is taken when running from the culprit-commit and using one of the changed files from that commit to illustrate the problem. The highlight for change-block 3/10 should match exactly the 1 green changed line slightly above it, but instead it covers 2 unchanged lines further down...

(This issue is the same, regardless of the Show All Lines and Ignore Whitespace Changes toggles.)

BTW, the very first change-block 1/10 of this diff (not shown in the screenshot) is correctly placed but highlighting 2 lines instead of 1.

However, if we reset to the commit before the culprit one, the issue is gone:

[goran-w]

OK - I found the culprit change. When splitting the call to the BlockNavigation constructor here, the 1st argument was mistakenly changed from Old to _data.Lines (a copy-paste mistake, from a similar change earlier in this file).

[love-linger]

merged