fix: Make path dependencies with the same name stays locked

src/cargo/core/resolver/encode.rs

@@ -202,7 +202,11 @@ impl EncodableResolve {
                 if !all_pkgs.insert(enc_id.clone()) {
                     anyhow::bail!("package `{}` is specified twice in the lockfile", pkg.name);
                 }
-                let id = match pkg.source.as_deref().or_else(|| path_deps.get(&pkg.name)) {
+                let id = match pkg
+                    .source
+                    .as_deref()
+                    .or_else(|| get_source_id(&path_deps, pkg))
+                {
                     // We failed to find a local package in the workspace.
                     // It must have been removed and should be ignored.
                     None => {
@@ -364,7 +368,11 @@ impl EncodableResolve {
 
         let mut unused_patches = Vec::new();
         for pkg in self.patch.unused {
-            let id = match pkg.source.as_deref().or_else(|| path_deps.get(&pkg.name)) {
+            let id = match pkg
+                .source
+                .as_deref()
+                .or_else(|| get_source_id(&path_deps, &pkg))
+            {
                 Some(&src) => PackageId::try_new(&pkg.name, &pkg.version, src)?,
                 None => continue,
             };
@@ -395,7 +403,7 @@ impl EncodableResolve {
             version = ResolveVersion::V2;
         }
 
-        Ok(Resolve::new(
+        return Ok(Resolve::new(
             g,
             replacements,
             HashMap::new(),
@@ -404,11 +412,42 @@ impl EncodableResolve {
             unused_patches,
             version,
             HashMap::new(),
-        ))
+        ));
+
+        fn get_source_id<'a>(
+            path_deps: &'a HashMap<String, HashMap<semver::Version, SourceId>>,
+            pkg: &'a EncodableDependency,
+        ) -> Option<&'a SourceId> {
+            {
+                if let Some(source_id) = path_deps.iter().find_map(|(name, version_source)| {
+                    // First look for cases where the version and name are the same
+                    if name == &pkg.name {
+                        if let Ok(pkg_version) = pkg.version.parse::<semver::Version>() {
+                            if let Some(source_id) = version_source.get(&pkg_version) {
+                                return Some(source_id);
+                            }
+                        }
+                    }
+                    None
+                }) {
+                    Some(source_id)
+                } else {
+                    // Next look for cases where the name is the same
+                    path_deps.iter().find_map(|(name, version_source)| {
+                        if name == &pkg.name {
+                            return version_source.values().next();
+                        }
+                        None
+                    })
+                }
+            }
+        }
     }
 }
 
-fn build_path_deps(ws: &Workspace<'_>) -> CargoResult<HashMap<String, SourceId>> {
+fn build_path_deps(
+    ws: &Workspace<'_>,
+) -> CargoResult<HashMap<String, HashMap<semver::Version, SourceId>>> {
     // If a crate is **not** a path source, then we're probably in a situation
     // such as `cargo install` with a lock file from a remote dependency. In
     // that case we don't need to fixup any path dependencies (as they're not
@@ -418,13 +457,15 @@ fn build_path_deps(ws: &Workspace<'_>) -> CargoResult<HashMap<String, SourceId>>
         .filter(|p| p.package_id().source_id().is_path())
         .collect::<Vec<_>>();
 
-    let mut ret = HashMap::new();
+    let mut ret: HashMap<String, HashMap<semver::Version, SourceId>> = HashMap::new();
     let mut visited = HashSet::new();
     for member in members.iter() {
-        ret.insert(
-            member.package_id().name().to_string(),
-            member.package_id().source_id(),
-        );
+        ret.entry(member.package_id().name().to_string())
+            .or_insert_with(HashMap::new)
+            .insert(
+                member.package_id().version().clone(),
+                member.package_id().source_id(),
+            );
         visited.insert(member.package_id().source_id());
     }
     for member in members.iter() {
@@ -444,7 +485,7 @@ fn build_path_deps(ws: &Workspace<'_>) -> CargoResult<HashMap<String, SourceId>>
     fn build_pkg(
         pkg: &Package,
         ws: &Workspace<'_>,
-        ret: &mut HashMap<String, SourceId>,
+        ret: &mut HashMap<String, HashMap<semver::Version, SourceId>>,
         visited: &mut HashSet<SourceId>,
     ) {
         for dep in pkg.dependencies() {
@@ -455,7 +496,7 @@ fn build_path_deps(ws: &Workspace<'_>) -> CargoResult<HashMap<String, SourceId>>
     fn build_dep(
         dep: &Dependency,
         ws: &Workspace<'_>,
-        ret: &mut HashMap<String, SourceId>,
+        ret: &mut HashMap<String, HashMap<semver::Version, SourceId>>,
         visited: &mut HashSet<SourceId>,
     ) {
         let id = dep.source_id();
@@ -467,7 +508,12 @@ fn build_path_deps(ws: &Workspace<'_>) -> CargoResult<HashMap<String, SourceId>>
             Err(_) => return,
         };
         let Ok(pkg) = ws.load(&path) else { return };
-        ret.insert(pkg.name().to_string(), pkg.package_id().source_id());
+        ret.entry(pkg.package_id().name().to_string())
+            .or_insert_with(HashMap::new)
+            .insert(
+                pkg.package_id().version().clone(),
+                pkg.package_id().source_id(),
+            );
         visited.insert(pkg.package_id().source_id());
         build_pkg(&pkg, ws, ret, visited);
     }

tests/testsuite/patch.rs

@@ -2939,12 +2939,12 @@ foo v0.0.0 ([ROOT]/foo)
             "\
 foo v0.0.0 ([ROOT]/foo)
 ├── bar v1.0.999 ([ROOT]/foo/bar-1-as-3)
-│   └── bar v3.0.1
+│   └── bar v3.0.0
 └── bar v2.0.999 ([ROOT]/foo/bar-2-as-3)
-    └── bar v3.0.1
+    └── bar v3.0.0
 ",
         )
         .run();
 
-    assert_ne!(p.read_file("Cargo.lock"), p.read_file("Cargo.lock.orig"));
-}
+    assert_eq!(p.read_file("Cargo.lock"), p.read_file("Cargo.lock.orig"));
+}