Merge pull request #4575 from IanButterworth/ib/1.12_source_fix

Author: IanButterworth

src/API.jl

@@ -207,7 +207,10 @@ function update_source_if_set(env, pkg)
             source["rev"] = pkg.repo.rev
         end
         if pkg.path !== nothing
-            source["path"] = pkg.path
+            # pkg.path is manifest-relative, but sources store project-relative paths
+            source["path"] = Types.manifest_path_to_project_path(
+                env.project_file, env.manifest_file, pkg.path
+            )
         end
 
         path, repo = get_path_repo(project, env.project_file, env.manifest_file, pkg.name)

test/workspaces.jl

@@ -203,6 +203,10 @@ end
                 manifest = TOML.parsefile("Manifest.toml")
                 parent_entry = only(manifest["deps"]["WorkspaceSourcesParent"])
                 @test parent_entry["path"] == "."
+                # Verify the Project.toml sources path was NOT corrupted (issue #4575)
+                # The path should remain ".." (project-relative), not "." (manifest-relative)
+                project = TOML.parsefile("docs/Project.toml")
+                @test project["sources"]["WorkspaceSourcesParent"]["path"] == ".."
             end
         end
     end