From 8442b2d3761795da1902aaa356c7a3468360d205 Mon Sep 17 00:00:00 2001
From: Hannes Karppila <hannes.karppila@gmail.com>
Date: Tue, 21 Mar 2023 00:09:41 +0200
Subject: [PATCH] Remove nested call limit (#399)

---
 fuel-asm/src/panic_reason.rs                     | 5 +----
 fuel-vm/src/interpreter/executors/instruction.rs | 4 ----
 fuel-vm/src/tests/flow.rs                        | 5 +++--
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/fuel-asm/src/panic_reason.rs b/fuel-asm/src/panic_reason.rs
index e469a24da6..72f7e47009 100644
--- a/fuel-asm/src/panic_reason.rs
+++ b/fuel-asm/src/panic_reason.rs
@@ -75,8 +75,6 @@ pub enum PanicReason {
     ContractIdAlreadyDeployed = 0x20,
     /// The loaded contract mismatch expectations.
     ContractMismatch = 0x21,
-    /// No more nested calls are allowed.
-    NestedCallLimitReached = 0x22,
     /// The byte can't be mapped to any known `PanicReason`.
     UnknownPanicReason = 0x23,
 }
@@ -139,7 +137,6 @@ impl From<u8> for PanicReason {
             0x1f => IllegalJump,
             0x20 => ContractIdAlreadyDeployed,
             0x21 => ContractMismatch,
-            0x22 => NestedCallLimitReached,
             _ => UnknownPanicReason,
         }
     }
@@ -166,7 +163,7 @@ mod tests {
 
     #[test]
     fn test_u8_panic_reason_round_trip() {
-        const LAST_PANIC_REASON: u8 = 0x23;
+        const LAST_PANIC_REASON: u8 = 0x22;
         for i in 0..LAST_PANIC_REASON {
             let reason = PanicReason::from(i);
             let i2 = reason as u8;
diff --git a/fuel-vm/src/interpreter/executors/instruction.rs b/fuel-vm/src/interpreter/executors/instruction.rs
index 36468ade8c..d125e11946 100644
--- a/fuel-vm/src/interpreter/executors/instruction.rs
+++ b/fuel-vm/src/interpreter/executors/instruction.rs
@@ -552,10 +552,6 @@ where
             Instruction::CALL(call) => {
                 let (a, b, c, d) = call.unpack();
 
-                if self.frames.len() >= VM_MAX_NESTED_CALLS {
-                    return Err(PanicReason::NestedCallLimitReached.into());
-                }
-
                 // Enter call context
                 self.prepare_call(a, b, c, d)?;
             }
diff --git a/fuel-vm/src/tests/flow.rs b/fuel-vm/src/tests/flow.rs
index 3cb02dc6bc..0db9257141 100644
--- a/fuel-vm/src/tests/flow.rs
+++ b/fuel-vm/src/tests/flow.rs
@@ -417,8 +417,9 @@ fn revert_from_call_immediately_ends_execution() {
     assert_eq!(revert_receipts.len(), 1);
 }
 
+/// Makes sure that infinte recursion with CALL instruction doesn't crash
 #[test]
-fn nested_call_limit() {
+fn repeated_nested_calls() {
     let rng = &mut StdRng::seed_from_u64(2322u64);
 
     let mut client = MemoryClient::default();
@@ -496,7 +497,7 @@ fn nested_call_limit() {
     if let Receipt::Panic { reason: pr, .. } = receipts.pop().expect("Missing panic reason receipt") {
         assert_eq!(
             *pr.reason(),
-            PanicReason::NestedCallLimitReached,
+            PanicReason::OutOfGas,
             "Panic reason differs for the expected reason"
         );
     } else {