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Dion Moult
cc54237f51
Loading a model whose first placement sits at the world origin
stack-overflowed BonsaiViewer instantly on Windows (and macOS).
WinDbg trace was a 5-frame Qt signal-slot cycle hitting the guard
page ~1400 levels deep; Linux escaped only because that machine's
iterator order put a non-origin instance first, which made the guess
return a non-default value and naturally terminated the recursion
after one step.
Root cause is the architecture, not the specific guard inside the
guess function. `ViewportView::refresh()` was connected to six
SessionState signals (projectReset, projectOpened, modelsChanged,
federationChanged, visibilityChanged, modelGeometryReady) and was
calling `maybeGuessFederatedFalseOrigin` on every model on every
fire. That helper called `session_state_->notifyFederationChanged()`
unconditionally after the mutation, which re-emitted
SessionState::federationChanged, which re-entered refresh(), which
re-entered the guess — a hidden emit-in-slot loop. The "current ==
defaults" guard at the top of the guess prevented further mutations
once the value moved off defaults, but on machines where the guess
itself returned defaults the guard never fired and the loop ran
forever.
Cleanup:
* refresh() is now terminal: it reads federation state, pushes it to
the viewport, and returns. No mutations, no signal emissions.
maybeGuessFederatedFalseOrigin is removed from its for-loop.
* The guess is renamed to `tryGuessFirstModelFalseOrigin(uint32_t)`
and is now invoked only from the modelGeometryReady connection,
not from refresh(). Conditions:
1. modelIds().size() == 1 (the just-loaded model is the only
model — i.e. this is the "first model added" edge)
2. federation->federatedFalseOrigin() == defaults (nobody has
set the origin yet — possibly because the previous attempt
guessed defaults and no-op'd, in which case we deliberately
want to retry next time a model lands)
No one-shot flag: add→remove→add cycles re-attempt the guess
precisely while the origin is still default, which is the right
semantics.
* SessionState now relays Federation::federatedFalseOriginChanged
onto its own bus via notifyFederationChanged. This replaces the
manual `session_state_->notifyFederationChanged()` call the old
guess made post-mutation. With the relay in place, any future
mutation site (commands, settings dialog, project load) will
propagate to views automatically — the emit point lives at the
data change, not at every caller. Views still subscribe to
SessionState only; Federation stays a back-end detail.
Reproduced with ISSUE_053_20181220Holter_Tower_10.ifcview on
Windows (build 21d3945, WinDbg `kn30` showed the recurring cycle
explicitly). Diagnosis confirmed on Linux by adding tracing prints
in refresh() and the guess body: same model, same code, but the
iterator's first-placement happened to be non-origin so the loop
terminated after one step.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
IfcOpenShell
IfcOpenShell is an open source (LGPL) software library for working with Industry Foundation Classes (IFC). Complete parsing support is provided for IFC2x3 TC1, IFC4 Add2 TC1, IFC4x1, IFC4x2, and IFC4x3 Add2. Extensive geometric support is implemented for the IFC releases IFC2x3 TC1 and IFC4 Add2 TC1. Extending with support for arbitrary IFC schemas is possible at compile-time when using C++ and at run-time when using Python.
In addition to a C++ and Python API, IfcOpenShell comes with an ecosystem of tools, notably including IfcConvert (an application to convert IFC models to other formats), Bonsai (an add-on to Blender providing a graphical IFC authoring platform), and many other libraries, CLI apps, and more. Support is also provided for auxiliary standards such as BCF and IDS.
For more information, see:
Development is sponsored through your generous donations!
Contents
| Name | Description | License | Service |
|---|---|---|---|
| bcf | Library to read and write BCF-XML and query OpenCDE BCF-API modules | LGPL-3.0-or-later |   |
| bonsai | Add-on to Blender providing a graphical native IFC authoring platform | GPL-3.0-or-later |    |
| bsdd | Library to query the bSDD API | LGPL-3.0-or-later |  |
| ifc2ca | Utility to convert IFC structural analysis models to Code_Aster | LGPL-3.0-or-later | |
| ifc4d | Convert to and from IFC and project management software | LGPL-3.0-or-later |  |
| ifc5d | Report and optimise cost information from IFC | LGPL-3.0-or-later |  |
| ifcbimtester | Wrapper for Gherkin based unit testing for IFC models | LGPL-3.0-or-later | |
| ifcblender | Historic Blender IFC import add-on | LGPL-3.0-or-later* | |
| ifccityjson | Convert CityJSON to IFC | LGPL-3.0-or-later |  |
| ifcclash | Clash detection library and CLI app | LGPL-3.0-or-later |  |
| ifcconvert | CLI app to convert IFC to many other formats | LGPL-3.0-or-later* |   |
| ifccsv | Library and CLI app to export and import schedules from IFC | LGPL-3.0-or-later |  |
| ifcdiff | Compare changes between IFC models | LGPL-3.0-or-later |  |
| ifcedit | CLI wrapper for ifcopenshell.api IFC model mutation functions | LGPL-3.0-or-later |  |
| ifcfm | Extract IFC data for FM handover requirements | LGPL-3.0-or-later |  |
| ifcmax | Historic extension for IFC support in 3DS Max | LGPL-3.0-or-later* | |
| ifcmcp | MCP server for querying and editing IFC building models | LGPL-3.0-or-later |  |
| ifcopenshell-python | Python library for IFC manipulation | LGPL-3.0-or-later* |         |
| ifcpatch | Utility to run pre-packaged scripts to manipulate IFCs | LGPL-3.0-or-later |  |
| ifcquery | CLI tool for querying and inspecting IFC building models | LGPL-3.0-or-later |  |
| ifcsverchok | Blender Add-on for visual node programming with IFC | GPL-3.0-or-later |  |
| ifctester | Library, CLI and webapp for IDS model auditing | LGPL-3.0-or-later |  |
The IfcOpenShell C++ codebase is split into multiple interal libraries:
| Name | Description | License |
|---|---|---|
| ifcgeom | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcgeom_schema_agnostic | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcgeomserver | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcjni | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcparse | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcwrap | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| qtviewer | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| serializers | Internal library for IfcOpenShell | LGPL-3.0-or-later* |