From 0b674bb8a66676e63189ba77700cf8239a26cfeb Mon Sep 17 00:00:00 2001
From: Alphonse Noni Mousse <39067955+a-noni-mousse@users.noreply.github.com>
Date: Sun, 7 May 2023 20:33:29 +0000
Subject: [PATCH] refactor: improve checking of path lengths (#4519)

Improve the checking of the path lengths during Payments. Previously,
the code that did the check of the payment path lengths was sometimes
executed, but without any effect. This changes it to only check when it
matters, and to not make unnecessary copies of the path vectors.
---
 src/ripple/app/tx/impl/Payment.cpp | 31 +++++++++---------------------
 1 file changed, 9 insertions(+), 22 deletions(-)

diff --git a/src/ripple/app/tx/impl/Payment.cpp b/src/ripple/app/tx/impl/Payment.cpp
index d3c26a37023..3903aa75045 100644
--- a/src/ripple/app/tx/impl/Payment.cpp
+++ b/src/ripple/app/tx/impl/Payment.cpp
@@ -270,27 +270,17 @@ Payment::preclaim(PreclaimContext const& ctx)
         return tecDST_TAG_NEEDED;
     }
 
-    if (paths || sendMax || !saDstAmount.native())
+    // Payment with at least one intermediate step and uses transitive balances.
+    if ((paths || sendMax || !saDstAmount.native()) && ctx.view.open())
     {
-        // Ripple payment with at least one intermediate step and uses
-        // transitive balances.
-
-        // Copy paths into an editable class.
-        STPathSet const spsPaths = ctx.tx.getFieldPathSet(sfPaths);
+        STPathSet const& paths = ctx.tx.getFieldPathSet(sfPaths);
 
-        auto pathTooBig = spsPaths.size() > MaxPathSize;
-
-        if (!pathTooBig)
-            for (auto const& path : spsPaths)
-                if (path.size() > MaxPathLength)
-                {
-                    pathTooBig = true;
-                    break;
-                }
-
-        if (ctx.view.open() && pathTooBig)
+        if (paths.size() > MaxPathSize ||
+            std::any_of(paths.begin(), paths.end(), [](STPath const& path) {
+                return path.size() > MaxPathLength;
+            }))
         {
-            return telBAD_PATH_COUNT;  // Too many paths for proposed ledger.
+            return telBAD_PATH_COUNT;
         }
     }
 
@@ -384,9 +374,6 @@ Payment::doApply()
             }
         }
 
-        // Copy paths into an editable class.
-        STPathSet spsPaths = ctx_.tx.getFieldPathSet(sfPaths);
-
         path::RippleCalc::Input rcInput;
         rcInput.partialPaymentAllowed = partialPaymentAllowed;
         rcInput.defaultPathsAllowed = defaultPathsAllowed;
@@ -404,7 +391,7 @@ Payment::doApply()
                 saDstAmount,
                 uDstAccountID,
                 account_,
-                spsPaths,
+                ctx_.tx.getFieldPathSet(sfPaths),
                 ctx_.app.logs(),
                 &rcInput);
             // VFALCO NOTE We might not need to apply, depending