Fix editor unsaved scenes getting file path updates

[Hrothdel]

Fixes #116703

Unsaved scenes were getting their path set to another empty string every time EditorData::get_scene_path was called for them. This caused a scene tree update, resulting in some jitter for resource previews. The jitter could probably be investigated further, as it would be nice for it to not happen even on scene tree updates, but this seems to solve the main problem for now.

[EBII]

❌ CI Report — PR #118225

Repository: godotengine/godot
Base branch: master
Overall: ❌ FAIL
Date: 2026-04-06 13:45 UTC

Checks

Check	Status	Details
merge_check	✅ pass	Clean merge with master
gitignore_check	✅ pass	OK
static_checks	✅ pass	All hooks passed
build	✅ pass	target=editor
doctool	✅ pass	API docs up to date
gdextension_api	✅ pass	API consistent
unit_tests	✅ pass	All tests passed
regression_cyclic	✅ pass	GDScript cyclic compilation OK
regression_gltf	⏭️ skip	Skipped
regression_project	✅ pass	Regression project passed
build_ubsan	❌ fail	GCC + UBSan (sans ASan) — detecte les undefined behaviors (target=editor) — EXIT_CODE=2 false positive GCC
build_clang	✅ pass	Clang (sans sanitizers) — detecte les bugs compilateur-specifiques (target=editor)

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_{test build with dagger ci auto coment PR CI par}

[Hrothdel]

build_ubsan ❌ fail

This might be an issue with your setup, this PR doesn't do anything that could result in only the ubsan build to fail, and it builds fine on my end using gcc. I also got a linking error when trying to build with clang, so something similar might also be happening for you.

[KoBeWi]

The problem comes from Node's set_scene_file_path() not checking if the new path is different and always calling _emit_editor_state_changed(), but the editor-side solution is less invasive.

[Repiteo]

Thanks!