Rm some offers where the quality is reduced:

Substantial reductions in an offer's effective quality from its
initial quality may clog offer books.

src/ripple/protocol/AmountConversions.h

@@ -63,11 +63,7 @@ toSTAmount(XRPAmount const& xrp, Issue const& iss)
 
 template <class T>
 T
-toAmount(STAmount const& amt)
-{
-    static_assert(sizeof(T) == -1, "Must use specialized function");
-    return T(0);
-}
+toAmount(STAmount const& amt) = delete;
 
 template <>
 inline STAmount
@@ -102,6 +98,28 @@ toAmount<XRPAmount>(STAmount const& amt)
     return XRPAmount(sMant);
 }
 
+template <class T>
+T
+toAmount(IOUAmount const& amt) = delete;
+
+template <>
+inline IOUAmount
+toAmount<IOUAmount>(IOUAmount const& amt)
+{
+    return amt;
+}
+
+template <class T>
+T
+toAmount(XRPAmount const& amt) = delete;
+
+template <>
+inline XRPAmount
+toAmount<XRPAmount>(XRPAmount const& amt)
+{
+    return amt;
+}
+
 }  // namespace ripple
 
 #endif

src/ripple/protocol/Feature.h

@@ -116,6 +116,7 @@ class FeatureCollections
         "TicketBatch",
         "FlowSortStrands",
         "fixSTAmountCanonicalize",
+        "fixRmSmallIncreasedQOffers",
     };
 
     std::vector<uint256> features;
@@ -376,6 +377,7 @@ extern uint256 const featureNegativeUNL;
 extern uint256 const featureTicketBatch;
 extern uint256 const featureFlowSortStrands;
 extern uint256 const fixSTAmountCanonicalize;
+extern uint256 const fixRmSmallIncreasedQOffers;
 
 }  // namespace ripple
 

src/ripple/protocol/Quality.h

@@ -132,6 +132,13 @@ public:
     /** Create a quality from the ratio of two amounts. */
     explicit Quality(Amounts const& amount);
 
+    /** Create a quality from the ratio of two amounts. */
+    template <class In, class Out>
+    Quality(TAmounts<In, Out> const& amount)
+        : Quality(Amounts(toSTAmount(amount.in), toSTAmount(amount.out)))
+    {
+    }
+
     /** Create a quality from the ratio of two amounts. */
     template <class In, class Out>
     Quality(Out const& out, In const& in)

src/ripple/protocol/impl/Feature.cpp

@@ -135,6 +135,7 @@ detail::supportedAmendments()
         "TicketBatch",
         "FlowSortStrands",
         "fixSTAmountCanonicalize",
+        "fixRmSmallIncreasedQOffers",
     };
     return supported;
 }
@@ -190,7 +191,8 @@ uint256 const
     featureNegativeUNL              = *getRegisteredFeature("NegativeUNL"),
     featureTicketBatch              = *getRegisteredFeature("TicketBatch"),
     featureFlowSortStrands          = *getRegisteredFeature("FlowSortStrands"),
-    fixSTAmountCanonicalize         = *getRegisteredFeature("fixSTAmountCanonicalize");
+    fixSTAmountCanonicalize         = *getRegisteredFeature("fixSTAmountCanonicalize"),
+    fixRmSmallIncreasedQOffers      = *getRegisteredFeature("fixRmSmallIncreasedQOffers");
 
 // The following amendments have been active for at least two years. Their
 // pre-amendment code has been removed and the identifiers are deprecated.