selector: fail safe instead of silently corrupting on ambiguous dotted keys

An unquoted query segment like "Foo.Bar.Baz" is ambiguous whenever a
pset is literally named "Foo.Bar" (see #6937, ifccsv spreadsheet
export/import). get_element_value already returned None for the
simple case, but if a shorter, coincidentally-named pset/property also
existed (e.g. pset "Foo" with property "Bar"), it silently returned
that unrelated value instead. set_element_value had the same problem
in reverse: it silently wrote into the wrong property/pset rather than
reporting the extra unresolved key. Both now fail safely (None / a
raised SetElementValueException) so bad data is never produced. The
documented quoted/regex query forms already round-trip correctly and
are unaffected. ifccsv now catches that exception per-column so one
unresolved query doesn't abort the whole import.

Generated with the assistance of an AI coding tool.

src/ifccsv/ifccsv.py

@@ -511,7 +511,10 @@ class IfcCsv:
             if any(pattern in key.lower() for pattern in SKIP_PATTERNS):
                 continue
 
-            ifcopenshell.util.selector.set_element_value(ifc_file, element, key, value, concat=concat)
+            try:
+                ifcopenshell.util.selector.set_element_value(ifc_file, element, key, value, concat=concat)
+            except ifcopenshell.util.selector.SetElementValueException as e:
+                print("Skipping column '{}' for element {}: {}".format(key, row[0], e))
 
 
 if __name__ == "__main__":

src/ifcopenshell-python/ifcopenshell/util/selector.py

@@ -557,6 +557,9 @@ def _get_element_value(element: ifcopenshell.entity_instance, keys: list[str]) -
                     else:
                         results.append(subvalue)
                 value = results
+        else:
+            # No more keys can be applied to a terminal value.
+            value = None
     return value
 
 
@@ -803,6 +806,12 @@ def set_element_value(
 
                 element = result
         elif isinstance(element, dict):  # Such as from the result of a prior get_pset
+            if len(keys) != i + 1:
+                raise SetElementValueException(
+                    f"Failed to set value '{value}' for element '{original_element}' with query '{query}': "
+                    f"'{key}' is not the last key. If a name contains a literal '.', quote it, "
+                    'e.g. "Pset.Name".Property or /Pset\\.Name/.Property.'
+                )
             pset = ifc_file.by_id(element["id"])
             if isinstance(key, re.Pattern):
                 for prop, prop_value in element.items():

src/ifcopenshell-python/test/util/test_selector.py

@@ -195,6 +195,27 @@ class TestGetElementValue(test.bootstrap.IFC4):
         assert subject.get_element_value(element, "/Pset_.*Common/.Status") == ["New"]
         assert subject.get_element_value(element, "/Pset_.*Common/.Status.0") == "New"
 
+    def test_selecting_a_pset_with_a_dot_in_its_name_requires_quoting(self):
+        # See #6937: a pset literally named "Foo.Bar" is ambiguous with an
+        # unquoted "Foo.Bar.Baz" query, since "." also separates keys.
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        pset = ifcopenshell.api.pset.add_pset(self.file, product=element, name="Foo.Bar")
+        ifcopenshell.api.pset.edit_pset(self.file, pset=pset, properties={"Baz": "correct"})
+
+        # Quoting resolves the ambiguity unambiguously.
+        assert subject.get_element_value(element, '"Foo.Bar".Baz') == "correct"
+        assert subject.get_element_value(element, r"/Foo\.Bar/.Baz") == "correct"
+
+        # An unquoted query fails silently rather than misresolving.
+        assert subject.get_element_value(element, "Foo.Bar.Baz") is None
+
+        # If a *different*, coincidentally-named pset also exists (e.g. "Foo"
+        # with a property "Bar"), the unquoted query must not silently return
+        # that unrelated value instead.
+        other_pset = ifcopenshell.api.pset.add_pset(self.file, product=element, name="Foo")
+        ifcopenshell.api.pset.edit_pset(self.file, pset=other_pset, properties={"Bar": "unrelated"})
+        assert subject.get_element_value(element, "Foo.Bar.Baz") is None
+
 
 class TestFilterElements(test.bootstrap.IFC4):
     def test_selecting_by_globalid(self):
@@ -440,6 +461,26 @@ class TestSetElementValue(test.bootstrap.IFC4):
         subject.set_element_value(self.file, layer, "Material.Name", "Foo")
         assert material.Name == "Foo"
 
+    def test_setting_a_pset_with_a_dot_in_its_name_requires_quoting(self):
+        # See #6937: an unquoted query must not silently write into an
+        # unrelated, coincidentally-named pset/property.
+        element = ifcopenshell.api.root.create_entity(self.file, ifc_class="IfcWall")
+        pset = ifcopenshell.api.pset.add_pset(self.file, product=element, name="Foo.Bar")
+        ifcopenshell.api.pset.edit_pset(self.file, pset=pset, properties={"Baz": "original"})
+        other_pset = ifcopenshell.api.pset.add_pset(self.file, product=element, name="Foo")
+        ifcopenshell.api.pset.edit_pset(self.file, pset=other_pset, properties={"Bar": "original_unrelated"})
+
+        with pytest.raises(subject.SetElementValueException):
+            subject.set_element_value(self.file, element, "Foo.Bar.Baz", "new_value")
+
+        # Neither pset should have been touched.
+        assert ifcopenshell.util.element.get_pset(element, "Foo.Bar")["Baz"] == "original"
+        assert ifcopenshell.util.element.get_pset(element, "Foo")["Bar"] == "original_unrelated"
+
+        # The quoted form is unambiguous and works.
+        subject.set_element_value(self.file, element, '"Foo.Bar".Baz', "new_value")
+        assert ifcopenshell.util.element.get_pset(element, "Foo.Bar")["Baz"] == "new_value"
+
 
 class TestSetElementValuePredefinedType(test.bootstrap.IFC4):
     def test_setting_an_element_predefined_type(self):