Return current directory without the trailing slash (JuliaLang#31417)

base/loading.jl

@@ -1428,5 +1428,6 @@ Return the current working directory if run from a REPL or if evaluated by `juli
 """
 macro __DIR__()
     __source__.file === nothing && return nothing
-    return abspath(dirname(String(__source__.file)))
+    _dirname = dirname(String(__source__.file))
+    return isempty(_dirname) ? pwd() : abspath(_dirname)
 end

base/path.jl

@@ -145,12 +145,16 @@ end
 """
     dirname(path::AbstractString) -> AbstractString
 
-Get the directory part of a path.
+Get the directory part of a path. Trailing characters ('/' or '\\') in the path are
+counted as part of the path.
 
 # Examples
 ```jldoctest
 julia> dirname("/home/myuser")
 "/home"
+
+julia> dirname("/home/myuser/")
+"/home/myuser"
 ```
 
 See also: [`basename`](@ref)

test/loading.jl

@@ -45,13 +45,16 @@ include_string_test_func = include_string(@__MODULE__, "include_string_test() =
 
 @test isdir(@__DIR__)
 @test @__DIR__() == dirname(@__FILE__)
+@test !endswith(@__DIR__, Base.Filesystem.path_separator)
 let exename = `$(Base.julia_cmd()) --compiled-modules=yes --startup-file=no`,
-    wd = sprint(show, abspath(pwd(), "")),
-    s_dir = sprint(show, joinpath(realpath(tempdir()), ""))
+    wd = sprint(show, pwd())
+    s_dir = sprint(show, realpath(tempdir()))
     @test wd != s_dir
     @test readchomp(`$exename -E "@__DIR__" -i`) == wd
     @test readchomp(`$exename -E "cd(()->eval(:(@__DIR__)), $s_dir)" -i`) == s_dir
     @test readchomp(`$exename -E "@__DIR__"`) == wd # non-interactive
+    @test !endswith(wd, Base.Filesystem.path_separator)
+    @test !endswith(s_dir, Base.Filesystem.path_separator)
 end
 
 # Issue #5789 and PR #13542: