Crash when searching in the layers panel
#### Summary:
In this particular file, when I search for anything in the layers panel, Inkscape crashes.
#### Steps to reproduce:
- Open Inkscape
- Open sample file
- Open layers panel
- Search something in the search field
#### What happened?
- Inkscape crashes after typing the first character (in my case, "r")
#### What should have happened?
- Layers list should be filtered according to the searched term
Sample attachments:
{width=329 height=600}
#### Version info
<pre>
0# Inkscape::Application::crash_handler(int) in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
1# _sigtramp in /usr/lib/system/libsystem_platform.dylib
2# Inkscape::UI::Dialog::ObjectsPanel::showChildInTree(SPItem*) in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
3# Inkscape::UI::Dialog::ObjectsPanel::showChildInTree(SPItem*) in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
4# Inkscape::UI::Dialog::ObjectWatcher::addChild(SPItem*, bool) in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
5# Inkscape::UI::Dialog::ObjectWatcher::ObjectWatcher(Inkscape::UI::Dialog::ObjectsPanel*, SPItem*, Gtk::TreeRow*, bool) in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
6# Inkscape::UI::Dialog::ObjectWatcher::addChild(SPItem*, bool) in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
7# Inkscape::UI::Dialog::ObjectWatcher::ObjectWatcher(Inkscape::UI::Dialog::ObjectsPanel*, SPItem*, Gtk::TreeRow*, bool) in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
8# Inkscape::UI::Dialog::ObjectsPanel::setRootWatcher() in /Applications/Inkscape.app/Contents/Frameworks/inkscape/libinkscape_base.1.5.0.0.dylib
9# (anonymous namespace)::SignalProxyNormal_slot0_void_callback(_GObject*, void*) in /Applications/Inkscape.app/Contents/Frameworks/libglibmm-2.68.1.dylib
10# _g_closure_invoke_va in /Applications/Inkscape.app/Contents/Frameworks/libgobject-2.0.0.dylib
11# signal_emit_valist_unlocked in /Applications/Inkscape.app/Contents/Frameworks/libgobject-2.0.0.dylib
12# g_signal_emit in /Applications/Inkscape.app/Contents/Frameworks/libgobject-2.0.0.dylib
13# gtk_search_entry_changed_timeout_cb in /Applications/Inkscape.app/Contents/Frameworks/libgtk-4.1.dylib
14# g_timeout_dispatch in /Applications/Inkscape.app/Contents/Frameworks/libglib-2.0.0.dylib
15# g_main_context_dispatch_unlocked in /Applications/Inkscape.app/Contents/Frameworks/libglib-2.0.0.dylib
16# g_main_context_iterate_unlocked in /Applications/Inkscape.app/Contents/Frameworks/libglib-2.0.0.dylib
17# g_main_context_iteration in /Applications/Inkscape.app/Contents/Frameworks/libglib-2.0.0.dylib
18# g_application_run in /Applications/Inkscape.app/Contents/Frameworks/libgio-2.0.0.dylib
19# main in /Applications/Inkscape.app/Contents/MacOS/Inkscape
</pre>
<details><summary>System info</summary>
Inkscape 1.5-dev (81a8d32, 2025-12-07)
Compile (Run)
GLib version: 2.83.4
GTK version: 4.20.2 (4.20.2)
glibmm version: 2.83.1
gtkmm version: 4.20.0
libxml2 version: 2.11.5
libxslt version: 1.1.35
Cairo version: 1.18.2 (1.18.2)
Pango version: 1.56.1 (1.56.1)
HarfBuzz version: 10.2.0 (10.2.0)
Poppler version: 24.02.0
OS version: macOS 15.5 (24F74) arm64
</details>
issue