From b28f62bbd9e4e003d67c3dc662a53df1a739e029 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.

Signed-off-by: Manoj Doshi <mdoshi@ripple.com>
---
 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 d3c26a3702..3903aa7504 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.
+        STPathSet const& paths = ctx.tx.getFieldPathSet(sfPaths);
 
-        // Copy paths into an editable class.
-        STPathSet const spsPaths = 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