Fix: Incorrect curves and pointcloud bounding boxes

The generic bounds utility used an incorrect initial value. The value
cannot be zero-initialized, because that breaks the case where all
values are greater than zero.

source/blender/blenlib/BLI_bounds.hh

@@ -28,10 +28,11 @@ template<typename T> static std::optional<MinMaxResult<T>> min_max(Span<T> value
   if (values.is_empty()) {
     return std::nullopt;
   }
+  const MinMaxResult<T> init{values.first(), values.first()};
   return threading::parallel_reduce(
       values.index_range(),
       1024,
-      MinMaxResult<T>(),
+      init,
       [&](IndexRange range, const MinMaxResult<T> &init) {
         MinMaxResult<T> result = init;
         for (const int i : range) {
@@ -55,10 +56,11 @@ static std::optional<MinMaxResult<T>> min_max_with_radii(Span<T> values, Span<Ra
   if (values.is_empty()) {
     return std::nullopt;
   }
+  const MinMaxResult<T> init{values.first(), values.first()};
   return threading::parallel_reduce(
       values.index_range(),
       1024,
-      MinMaxResult<T>(),
+      init,
       [&](IndexRange range, const MinMaxResult<T> &init) {
         MinMaxResult<T> result = init;
         for (const int i : range) {

source/blender/blenlib/tests/BLI_bounds_test.cc

@@ -33,6 +33,13 @@ TEST(bounds, MinMaxFloat)
   EXPECT_EQ(result->max, 3.0f);
 }
 
+TEST(bounds, MinGreaterThanZero)
+{
+  Array<float> data = {1.5f, 3.0f, 1.1f, 100.0f};
+  auto result = bounds::min_max(data.as_span());
+  EXPECT_GT(result->min, 1.0f);
+}
+
 TEST(bounds, MinMaxRadii)
 {
   Array<int2> data = {int2(0, 1), int2(3, -1), int2(0, -2), int2(-1, 1)};