Duplicate gutter icons are displayed

[xterao]

Describe the bug
When opening an SQL file from the search results, if the search window remains open, the gutter icon for jumping to a DAO method is displayed twice.

To Reproduce
Steps to reproduce the behavior:

1. Open the “Search” window and search for any string.
2. Press Ctrl+Enter to pin the search window.
3. Select a file from the search results to open it in the editor
4. Make any modification to the first line of the file.
5. Observe that the gutter icon is displayed multiple times.

Expected behavior
Even when the same file is open in multiple windows, only a single gutter icon should be displayed.

Screenshots

Desktop :

• IntelliJ Community 2024.3.1
• Doma Tools Version : 1.0.0 or 0.8.0

[xterao]

Upon investigating the gutter icon rendering, we discovered that the IntelliJ platform invokes the provider logic separately for each view.
https://github.com/JetBrains/intellij-community/blob/1708c46d3dae4f9d0488989365e206e7661a4fd1/platform/lang-impl/src/com/intellij/ide/actions/RelatedItemLineMarkerGotoAdapter.java#L44

While there is control to prevent a LineMarkerInfo generated in one view from being applied to the same file in that view, there doesn’t appear to be any deduplication of LineMarkerInfos across different views.

Because this issue only occurs intermittently—depending on file-update timing when multiple views are open—we’ll hold off on addressing it for now.

[xterao]

Since DAO-method gutter icons aren’t affected by this issue, it seems that gutter markers for elements inheriting from PsiNameIdentifierOwner do not duplicate.
In our SQL handling, we don’t target PsiNameIdentifierOwner objects because we use custom-language element classes. In the future, we might explore having our custom-language classes extend PsiNameIdentifierOwner to validate this behavior.