ScalingSettings::MinPartiality: validate the argument, not the value it replaces

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015CeEGgpKdfkCTJb3YNMJcu
(cherry picked from commit df5f2ae22f979a5569f4d569fe2a8cdd5999d242)

common/ScalingSettings.cpp

@@ -90,7 +90,7 @@ std::optional<double> ScalingSettings::GetRotationWedgeForScaling() const {
 }
 
 ScalingSettings &ScalingSettings::MinPartiality(double input) {
-    if (min_partiality < 0.0 || min_partiality > 1.0)
+    if (!(input >= 0.0 && input <= 1.0))
         throw JFJochException(JFJochExceptionCategory::InputParameterInvalid, "Min partiality must be between 0 and 1");
     min_partiality = input;
     return *this;

tests/MergeScaleTest.cpp

@@ -1143,3 +1143,12 @@ TEST_CASE("MergeOnTheFly_CaptureTermDownweightsPartials") {
     CHECK(with < without);
     CHECK(with < 1.08f);
 }
+
+// The setter checks the value it is given, not the one it replaces.
+TEST_CASE("ScalingSettings_MinPartialityRange") {
+    ScalingSettings s;
+    CHECK_THROWS(s.MinPartiality(1.5));
+    CHECK_THROWS(s.MinPartiality(-0.1));
+    CHECK_NOTHROW(s.MinPartiality(0.5));
+    CHECK(s.GetMinPartiality() == 0.5);
+}