Throw on reversed range in AddRange for consistency

A reversed range (start > end) indicates a bug in the caller and
should fail fast with std::invalid_argument rather than silently
succeed. An empty range (start == end) remains a valid no-op.

This makes AddRange behavior consistent across the Java, C++, and
Rust Iceberg implementations.

Author: Baunsgaard

src/iceberg/deletes/roaring_position_bitmap.cc

@@ -22,6 +22,7 @@
 #include <cstring>
 #include <exception>
 #include <limits>
+#include <stdexcept>
 #include <utility>
 #include <vector>
 
@@ -128,7 +129,12 @@ void RoaringPositionBitmap::Add(int64_t pos) {
 }
 
 void RoaringPositionBitmap::AddRange(int64_t pos_start, int64_t pos_end) {
-  if (pos_start >= pos_end) {
+  if (pos_start > pos_end) {
+    throw std::invalid_argument(
+        "AddRange requires pos_start <= pos_end, got [" + std::to_string(pos_start) +
+        ", " + std::to_string(pos_end) + ")");
+  }
+  if (pos_start == pos_end) {
     return;
   }
   pos_start = std::max(pos_start, int64_t{0});

src/iceberg/deletes/roaring_position_bitmap.h

@@ -67,7 +67,8 @@ class ICEBERG_EXPORT RoaringPositionBitmap {
   /// \brief Sets a range of positions [pos_start, pos_end).
   /// \param pos_start the start of the range (inclusive), clamped to 0
   /// \param pos_end the end of the range (exclusive), clamped to kMaxPosition + 1
-  /// \note If pos_start >= pos_end after clamping, this method does nothing.
+  /// \throws std::invalid_argument if pos_start > pos_end
+  /// \note If pos_start == pos_end, this method does nothing.
   ///       Positions outside [0, kMaxPosition] are silently ignored.
   void AddRange(int64_t pos_start, int64_t pos_end);
 

src/iceberg/test/roaring_position_bitmap_test.cc

@@ -25,6 +25,7 @@
 #include <fstream>
 #include <random>
 #include <set>
+#include <stdexcept>
 #include <string>
 #include <vector>
 
@@ -203,8 +204,7 @@ TEST_P(RoaringPositionBitmapAddRangeNoOpTest, IsNoOp) {
 
 INSTANTIATE_TEST_SUITE_P(
     AddRangeNoOpScenarios, RoaringPositionBitmapAddRangeNoOpTest,
-    ::testing::Values(AddRangeNoOpParams{.name = "reversed", .start = 100, .end = 50},
-                      AddRangeNoOpParams{.name = "equal", .start = 100, .end = 100},
+    ::testing::Values(AddRangeNoOpParams{.name = "equal", .start = 100, .end = 100},
                       AddRangeNoOpParams{.name = "zero_length_at_zero",
                                          .start = 0,
                                          .end = 0},
@@ -215,6 +215,11 @@ INSTANTIATE_TEST_SUITE_P(
       return info.param.name;
     });
 
+TEST(RoaringPositionBitmapTest, TestAddRangeReversedThrows) {
+  RoaringPositionBitmap bitmap;
+  ASSERT_THROW(bitmap.AddRange(100, 50), std::invalid_argument);
+}
+
 struct OrParams {
   const char* name;
   std::set<int64_t> lhs_input;