From 5539c0f53c05f1cdd95a0457b1f3277284ee8cb3 Mon Sep 17 00:00:00 2001
From: Jernej Kos <jernej@kos.mx>
Date: Sat, 15 Jul 2023 23:12:08 +0200
Subject: [PATCH] runtime-sdk/modules/evm: Make custom ABI-encoded error
 decoding easier

---
 runtime-sdk/modules/evm/src/lib.rs  | 16 +++-------------
 runtime-sdk/modules/evm/src/test.rs |  6 +++---
 2 files changed, 6 insertions(+), 16 deletions(-)

diff --git a/runtime-sdk/modules/evm/src/lib.rs b/runtime-sdk/modules/evm/src/lib.rs
index f0fe9294d8..5954e72a0b 100644
--- a/runtime-sdk/modules/evm/src/lib.rs
+++ b/runtime-sdk/modules/evm/src/lib.rs
@@ -230,26 +230,16 @@ fn process_evm_result(exit_reason: evm::ExitReason, data: Vec<u8>) -> Result<Vec
             const MIN_SIZE: usize = FIELD_REASON_START;
             const MAX_REASON_SIZE: usize = 1024;
 
-            let max_raw_len = if data.len() > MAX_REASON_SIZE {
-                MAX_REASON_SIZE
-            } else {
-                data.len()
-            };
+            let max_raw_len = data.len().clamp(0, MAX_REASON_SIZE);
             if data.len() < MIN_SIZE || !data.starts_with(ERROR_STRING_SELECTOR) {
-                return Err(Error::Reverted(format!(
-                    "invalid reason prefix: '{}'",
-                    base64::encode(&data[..max_raw_len])
-                )));
+                return Err(Error::Reverted(base64::encode(&data[..max_raw_len])));
             }
             // Decode and validate length.
             let mut length =
                 primitive_types::U256::from(&data[FIELD_LENGTH_START..FIELD_LENGTH_START + 32])
                     .low_u32() as usize;
             if FIELD_REASON_START + length > data.len() {
-                return Err(Error::Reverted(format!(
-                    "invalid reason length: '{}'",
-                    base64::encode(&data[..max_raw_len])
-                )));
+                return Err(Error::Reverted(base64::encode(&data[..max_raw_len])));
             }
             // Make sure that this doesn't ever return huge reason values as this is at least
             // somewhat contract-controlled.
diff --git a/runtime-sdk/modules/evm/src/test.rs b/runtime-sdk/modules/evm/src/test.rs
index 253dd4d529..d08f77faac 100644
--- a/runtime-sdk/modules/evm/src/test.rs
+++ b/runtime-sdk/modules/evm/src/test.rs
@@ -837,7 +837,7 @@ fn test_revert_reason_decoding() {
         // Malformed output, incorrect selector and bad length.
         (
             "BADBADBADBADBADBAD",
-            "invalid reason prefix: 'utututututut'",
+            "utututututut",
         ),
         // Malformed output, bad selector.
         (
@@ -845,7 +845,7 @@ fn test_revert_reason_decoding() {
             0000000000000000000000000000000000000000000000000000000000000020\
             0000000000000000000000000000000000000000000000000000000000000018\
             4461692f696e73756666696369656e742d62616c616e63650000000000000000",
-            "invalid reason prefix: 'uqqqrQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABhEYWkvaW5zdWZmaWNpZW50LWJhbGFuY2UAAAAAAAAAAA=='",
+            "uqqqrQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABhEYWkvaW5zdWZmaWNpZW50LWJhbGFuY2UAAAAAAAAAAA==",
         ),
         // Malformed output, corrupted length.
         (
@@ -853,7 +853,7 @@ fn test_revert_reason_decoding() {
             0000000000000000000000000000000000000000000000000000000000000020\
             00000000000000000000000000000000000000000000000000000000FFFFFFFF\
             4461692f696e73756666696369656e742d62616c616e63650000000000000000",
-            "invalid reason length: 'CMN5oAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP////9EYWkvaW5zdWZmaWNpZW50LWJhbGFuY2UAAAAAAAAAAA=='",
+            "CMN5oAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAP////9EYWkvaW5zdWZmaWNpZW50LWJhbGFuY2UAAAAAAAAAAA==",
         ),
     ];