vm: fix consensus ordering for regtest

Closes #273

.github/workflows/build.yml

@@ -57,7 +57,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        toolchain: [ nightly, beta, stable, 1.75.0 ]
+        toolchain: [ nightly, beta, stable, 1.76.0 ]
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master

Cargo.toml

@@ -10,7 +10,7 @@ categories = ["cryptography::cryptocurrencies"]
 readme = "README.md"
 license = "Apache-2.0"
 edition = "2021"
-rust-version = "1.75.0"
+rust-version = "1.76.0"
 exclude = [".github"]
 
 [lib]

MANIFEST.yml

@@ -3,7 +3,7 @@ Type: Library
 Kind: Free software
 License: Apache-2.0
 Language: Rust
-Compiler: 1.75
+Compiler: 1.76
 Author: Maxim Orlovsky
 Maintained: LNP/BP Standards Association, Switzerland
 Maintainers:

src/vm/contract.rs

@@ -324,10 +324,16 @@ impl Ord for WitnessPos {
     /// timestamp information and not height. The timestamp data are consistent
     /// across multiple blockchains, while height evolves with a different
     /// speed and can't be used in comparisons.
+    ///
+    /// If the timestamp of two witnesses is the same, we use the height for the ordering. This
+    /// might be the case for regtests, where multiple blocks can be mined with the same timestamp.
     fn cmp(&self, other: &Self) -> Ordering {
         assert!(self.timestamp > 0);
         assert!(other.timestamp > 0);
-        self.timestamp.cmp(&other.timestamp)
+        match self.timestamp.cmp(&other.timestamp) {
+            Ordering::Equal => self.height.cmp(&other.height),
+            ordering => ordering,
+        }
     }
 }