Draft: fix: Hash mismatch for empty dependencies

src/manifest.rs

@@ -1349,6 +1349,52 @@ mod tests {
             assert!(serialized.contains("[package]"));
             assert!(serialized.contains("test"));
         }
+
+        #[test]
+        fn packages_manifest_serialization_is_consistent_regardless_of_empty_dependencies_section() {
+            // A manifest with an empty [dependencies] section should serialize
+            // identically to a manifest without a [dependencies] section.
+            // This is important for reproducible package hashes.
+            use crate::lock::DigestAlgorithm;
+
+            let toml_with_empty_deps = r#"
+                edition = "0.12"
+
+                [package]
+                type = "lib"
+                name = "test"
+                version = "1.0.0"
+
+                [dependencies]
+            "#;
+
+            let toml_without_deps = r#"
+                edition = "0.12"
+
+                [package]
+                type = "lib"
+                name = "test"
+                version = "1.0.0"
+            "#;
+
+            let manifest_with = PackagesManifest::from_str(toml_with_empty_deps).expect("should parse");
+            let manifest_without = PackagesManifest::from_str(toml_without_deps).expect("should parse");
+
+            let serialized_with: String = manifest_with.try_into().expect("should serialize");
+            let serialized_without: String = manifest_without.try_into().expect("should serialize");
+
+            let hash_with = DigestAlgorithm::SHA256.digest(serialized_with.as_bytes());
+            let hash_without = DigestAlgorithm::SHA256.digest(serialized_without.as_bytes());
+
+            assert_eq!(
+                hash_with, hash_without,
+                "Package hashes must be identical for reproducible builds.\n\
+                 Hash with [dependencies]:    {}\n\
+                 Hash without [dependencies]: {}\n\n\
+                 With [dependencies]:\n{}\n\nWithout [dependencies]:\n{}",
+                hash_with, hash_without, serialized_with, serialized_without
+            );
+        }
     }
 
     // ===== WorkspaceManifest Tests =====