Fix UndefVarError due to unintentional signature change (#43173)

* Fix UndefVarError due to unintentional signature change

* Add wait for REPL task to exit

* Add test

* test fix

* no invoke

Author: BioTurboNick

base/client.jl

@@ -106,7 +106,7 @@ end
 display_error(stack::ExceptionStack) = display_error(stderr, stack)
 
 # these forms are depended on by packages outside Julia
-function display_error(io::IO, exception, backtrace)
+function display_error(io::IO, er, bt)
     printstyled(io, "ERROR: "; bold=true, color=Base.error_color())
     showerror(IOContext(io, :limit => true), er, bt, backtrace = bt!==nothing)
     println(io)

stdlib/REPL/test/repl.jl

@@ -1402,4 +1402,6 @@ fake_repl() do stdin_write, stdout_read, repl
     @test readline(stdout_read) == "\e[0m1-element ExceptionStack:"
     @test readline(stdout_read) == "UndefVarError: foobar not defined"
     @test readline(stdout_read) == "Stacktrace:"
+    write(stdin_write, '\x04')
+    Base.wait(repltask)
 end

test/client.jl

@@ -43,3 +43,12 @@ end
     err_str = String(take!(errio))
     @test occursin(nested_error_pattern, err_str)
 end
+
+@testset "display_error(io, er, bt) works" begin
+    errio = IOBuffer()
+    Base.display_error(errio, ErrorException, [])
+    err_str = String(take!(errio))
+    @test occursin(r"""
+        ERROR: ErrorException
+        """s, err_str)
+end