Spacer can crash on small HORN/ADT benchmarks when model construction
reaches datatype enodes without a fully populated constructor state. The
failure manifested as a null/invalid-path dereference inside datatype
model value generation.
- **Root cause area: datatype model extraction path**
- Hardened `theory_datatype::mk_value` to handle incomplete theory state
safely instead of assuming constructor metadata is always present.
- Added guarded fallback to a factory-provided datatype value when:
- `th_var` is missing,
- union-find lookup is invalid,
- var data/constructor is unavailable.
- **Behavioral change**
- Missing constructor state now degrades to a safe model value
(`expr_wrapper_proc`) instead of crashing during model generation.
- **Regression coverage**
- Added a focused API regression in `src/test/api_datalog.cpp` using a
Spacer + ADT HORN script (with reproducing seed) to ensure the code path
executes without parser/runtime failure.
```cpp
// theory_datatype::mk_value fallback shape
if (v == null_theory_var || invalid_var_data || d->m_constructor == nullptr) {
app* val = to_app(m_factory->get_some_value(n->get_sort()));
return alloc(expr_wrapper_proc, val);
}
```
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Daily Test Coverage Improver: Add comprehensive API Datalog tests
This commit adds comprehensive test coverage for Z3's Datalog/fixedpoint API functions, improving coverage from 0% to 17% (84/486 lines) in src/api/api_datalog.cpp.
Key improvements:
- Tests for Z3_mk_finite_domain_sort and Z3_get_finite_domain_sort_size
- Tests for Z3_mk_fixedpoint, reference counting, and basic operations
- Coverage for string conversion, statistics, and reason unknown functions
- Comprehensive error handling and edge case testing
🤖 Generated with [Claude Code](https://claude.ai/code)
Co-Authored-By: Claude <noreply@anthropic.com>
* staged files
* remove files
---------
Co-authored-by: Daily Test Coverage Improver <github-actions[bot]@users.noreply.github.com>
Co-authored-by: Claude <noreply@anthropic.com>