truncate the old style hash

Author: Zoran Cvetkov

graph/Cargo.toml

@@ -48,6 +48,7 @@ serde_derive = { workspace = true }
 serde_json = { workspace = true }
 serde_regex = { workspace = true }
 serde_yaml = { workspace = true }
+sha2 = "0.10.8"
 slog = { version = "2.7.0", features = [
     "release_max_level_trace",
     "max_level_trace",

graph/src/components/subgraph/proof_of_indexing/online.rs

@@ -132,9 +132,14 @@ impl BlockEventStream {
             }
             Hashers::Fast(mut digest) => {
                 if let Some(prev) = prev {
-                    let prev = prev
-                        .try_into()
-                        .expect("Expected valid fast stable hash representation");
+                    let prev = if prev.len() == 32 {
+                        prev.try_into()
+                            .expect("Expected valid fast stable hash representation")
+                    } else {
+                        prev[..32]
+                            .try_into()
+                            .expect("Expected valid fast stable hash representation")
+                    };
                     let prev = FastStableHasher::from_bytes(prev);
                     digest.mixin(&prev);
                 }