From 5ab62f4422f830c421e75f6b7efd3535cf54def5 Mon Sep 17 00:00:00 2001
From: Ed Hennis <ed@ripple.com>
Date: Tue, 27 Jan 2026 19:07:08 -0500
Subject: [PATCH] Clean-ups and tweaks

---
 include/xrpl/basics/Number.h    |  4 ++--
 src/libxrpl/basics/Number.cpp   |  7 ++++---
 src/test/basics/Number_test.cpp | 20 +++++++++++++++++++-
 3 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/include/xrpl/basics/Number.h b/include/xrpl/basics/Number.h
index 09dfe53651..2854ae7bc2 100644
--- a/include/xrpl/basics/Number.h
+++ b/include/xrpl/basics/Number.h
@@ -632,7 +632,7 @@ private:
 
     /** Breaks down the number into components, potentially de-normalizing it.
      *
-     * Ensures that the mantissa always has range_.log digits.
+     * Ensures that the mantissa always has range_.log + 1 digits.
      *
      */
     template <detail::UnsignedMantissa Rep = internalrep>
@@ -641,7 +641,7 @@ private:
 
     /** Breaks down the number into components, potentially de-normalizing it.
      *
-     * Ensures that the mantissa always has range_.log digits.
+     * Ensures that the mantissa always has range_.log + 1 digits.
      *
      */
     template <detail::UnsignedMantissa Rep = internalrep>
diff --git a/src/libxrpl/basics/Number.cpp b/src/libxrpl/basics/Number.cpp
index 71bbb7dbf5..0b2ff09eba 100644
--- a/src/libxrpl/basics/Number.cpp
+++ b/src/libxrpl/basics/Number.cpp
@@ -293,7 +293,8 @@ Number::Guard::doRound(rep& drops, std::string_view location)
     auto r = round();
     if (r == 1 || (r == 0 && (drops & 1) == 1))
     {
-        if (drops >= maxMantissa())
+        auto const& range = range_.get();
+        if (drops >= range.max)
         {
             static_assert(sizeof(internalrep) == sizeof(rep));
             // This should be impossible, because it's impossible to represent
@@ -1120,7 +1121,7 @@ Number::root(MantissaRange const& range, Number f, unsigned d)
 
         // Scale f into the range (0, 1) such that the scale change (e) is a
         // multiple of the root (d)
-        auto e = exponent + Number::mantissaLog() + 1;
+        auto e = exponent + range.log + 1;
         auto const di = static_cast<int>(d);
         auto ex = [e = e, di = di]()  // Euclidean remainder of e/d
         {
@@ -1213,7 +1214,7 @@ root2(Number f)
 
         // Scale f into the range (0, 1) such that f's exponent is a
         // multiple of d
-        auto e = exponent + Number::mantissaLog() + 1;
+        auto e = exponent + range.log + 1;
         if (e % 2 != 0)
             ++e;
         f = f.shiftExponent(-e);  // f /= 10^e;
diff --git a/src/test/basics/Number_test.cpp b/src/test/basics/Number_test.cpp
index 078c2fa57c..314e0f58e6 100644
--- a/src/test/basics/Number_test.cpp
+++ b/src/test/basics/Number_test.cpp
@@ -228,6 +228,25 @@ public:
                     // result will overflow. With addition using uint128_t,
                     // there's no problem. After normalizing, the resulting
                     // mantissa ends up less than largestMantissa.
+                    Number{
+                        false,
+                        Number::largestMantissa,
+                        0,
+                        Number::normalized{}},
+                    Number{
+                        false,
+                        Number::largestMantissa,
+                        0,
+                        Number::normalized{}},
+                    Number{
+                        false,
+                        Number::largestMantissa * 2,
+                        0,
+                        Number::normalized{}},
+                },
+                {
+                    // These mantissas round down, so adding them together won't
+                    // have any consequences.
                     Number{
                         false,
                         9'999'999'999'999'999'990ULL,
@@ -604,7 +623,6 @@ public:
                          Number::normalized{}},
                      __LINE__},
                     // Maximum actual mantissa range - same as int64
-                    // 99'999'999'999'999'999'800'000'000'000'000'000'100
                     {Number{false, maxMantissa, 0, Number::normalized{}},
                      Number{false, maxMantissa, 0, Number::normalized{}},
                      Number{85'070'591'730'234'615'84, 19},