Look for package name in [extras] for Preferences (#43361)

* Look for package name in `[extras]`

When Preferences.jl set's a preferences in a non-top-level package,
it adds that package to the `[extras]` entries in the project path.

Package loading should have used thhose entries to map the module uuid
to the key name in the Preferences.toml

Fixes JuliaPackaging/Preferences.jl#24

Co-authored-by: Elliot Saba <[email protected]>
(cherry picked from commit 8197c41)

base/loading.jl

@@ -1652,7 +1652,8 @@ function srctext_files(f::IO, srctextpos::Int64)
 end
 
 # Test to see if this UUID is mentioned in this `Project.toml`; either as
-# the top-level UUID (e.g. that of the project itself) or as a dependency.
+# the top-level UUID (e.g. that of the project itself), as a dependency,
+# or as a extra for Preferences.
 function get_uuid_name(project::Dict{String, Any}, uuid::UUID)
  uuid_p = get(project, "uuid", nothing)::Union{Nothing, String}
  name = get(project, "name", nothing)::Union{Nothing, String}
@@ -1667,6 +1668,16 @@ function get_uuid_name(project::Dict{String, Any}, uuid::UUID)
  end
  end
  end
+ for subkey in ("deps", "extras")
+ subsection = get(project, subkey, nothing)::Union{Nothing, Dict{String, Any}}
+ if subsection !== nothing
+ for (k, v) in subsection
+ if uuid == UUID(v::String)
+ return k
+ end
+ end
+ end
+ end
  return nothing
 end
 

test/loading.jl

@@ -189,6 +189,42 @@ end
  end
 end
 
+# extras
+@testset "extras" begin
+ mktempdir() do dir
+ project_file = joinpath(dir, "Project.toml")
+ touch(project_file) # dummy_uuid calls realpath
+ # various UUIDs to work with
+ proj_uuid = dummy_uuid(project_file)
+ root_uuid = uuid4()
+ this_uuid = uuid4()
+
+ old_load_path = copy(LOAD_PATH)
+ try
+ copy!(LOAD_PATH, [project_file])
+ write(project_file, """
+ name = "Root"
+ uuid = "$root_uuid"
+ [extras]
+ This = "$this_uuid"
+ """)
+ # look up various packages by name
+ root = Base.identify_package("Root")
+ this = Base.identify_package("This")
+ that = Base.identify_package("That")
+
+ @test root.uuid == root_uuid
+ @test this == nothing
+ @test that == nothing
+
+ @test Base.get_uuid_name(project_file, this_uuid) == "This"
+ finally
+ copy!(LOAD_PATH, old_load_path)
+ end
+ end
+end
+
+
 ## functional testing of package identification, location & loading ##
 
 saved_load_path = copy(LOAD_PATH)