Make at-__DIR__ return pwd() when run interactively

base/loading.jl

@@ -518,7 +518,11 @@ end
 
 function source_dir()
     p = source_path(nothing)
-    p === nothing ? p : dirname(p)
+    if p === nothing
+        isinteractive() ? pwd() : p
+    else
+        dirname(p)
+    end
 end
 
 """
@@ -534,8 +538,8 @@ macro __FILE__() source_path() end
     @__DIR__ -> AbstractString
 
 `@__DIR__` expands to a string with the directory part of the absolute path of the file
-containing the macro. Returns `nothing` if run from a REPL or an empty string if
-evaluated by `julia -e <expr>`.
+containing the macro. Returns the current working directory if run from a REPL or an empty
+string if evaluated by `julia -e <expr>`.
 """
 macro __DIR__() source_dir() end
 

test/loading.jl

@@ -14,6 +14,12 @@ include_string_test_func = include_string("include_string_test() = @__FILE__", t
 
 @test isdir(@__DIR__)
 @test @__DIR__() == dirname(@__FILE__)
+let exename = `$(Base.julia_cmd()) --precompiled=yes --startup-file=no`
+    wd = string('"', pwd(), '"')
+    @test readchomp(`$exename -E "@__DIR__" -i`) == wd
+    @test readchomp(`$exename -E "cd(()->@__DIR__, tempdir())" -i`) != wd
+    @test readchomp(`$exename -E "@__DIR__"`) == "\"nothing\"" # non-interactive
+end
 
 # Issue #5789 and PR #13542:
 mktempdir() do dir