Restore stacktrace scrubing in fallback REPL. (#59241)

Fixes #59223 by adding intermediary function names to use the same
`__repl_entry` prefix.

Author: BioTurboNick

base/client.jl

@@ -120,6 +120,10 @@ function display_error(io::IO, er, bt)
 end
 display_error(er, bt=nothing) = display_error(stderr, er, bt)
 
+# N.B.: Any functions starting with __repl_entry cut off backtraces when printing in the REPL.
+__repl_entry_client_lower(mod::Module, @nospecialize(ast)) = Meta.lower(mod, ast)
+__repl_entry_client_eval(mod::Module, @nospecialize(ast)) = Core.eval(mod, ast)
+
 function eval_user_input(errio, @nospecialize(ast), show_value::Bool)
     errcount = 0
     lasterr = nothing
@@ -136,8 +140,8 @@ function eval_user_input(errio, @nospecialize(ast), show_value::Bool)
                 errcount = 0
                 lasterr = nothing
             else
-                ast = Meta.lower(Main, ast)
-                value = Core.eval(Main, ast)
+                ast = __repl_entry_client_lower(Main, ast)
+                value = __repl_entry_client_eval(Main, ast)
                 setglobal!(Base.MainInclude, :ans, value)
                 if !(value === nothing) && show_value
                     if have_color

test/client.jl

@@ -1,5 +1,7 @@
 # This file is a part of Julia. License is MIT: https://julialang.org/license
 
+import Base.StackTraces: StackFrame
+
 nested_error_expr = quote
     try
         __not_a_binding__
@@ -57,3 +59,34 @@ end
     @test eval(:(ans = 1)) == 1
     @test eval(:(err = 1)) == 1
 end
+
+@testset "scrub REPL-related frames" begin
+    repl_bt = [StackFrame(:foo, "foo.jl", 1),
+          StackFrame(:__repl_entry_anysuffix, "client.jl", 2),
+          StackFrame(:bar, "bar.jl", 3)]
+    scrubbed_repl_bt = Base.scrub_repl_backtrace(repl_bt)
+
+    nonrepl_bt = [StackFrame(:foo, "foo.jl", 1),
+          StackFrame(:baz, "baz.jl", 2),
+          StackFrame(:bar, "bar.jl", 3)]
+    scrubbed_nonrepl_bt = Base.scrub_repl_backtrace(nonrepl_bt)
+
+    @test length(scrubbed_repl_bt) == 1
+    @test scrubbed_repl_bt[1].func == :foo
+    @test length(scrubbed_nonrepl_bt) == 3
+
+    errio = IOBuffer()
+    lower_errexpr = :(@bad)
+    Base.eval_user_input(errio, lower_errexpr, false)
+    outstr = String(take!(errio))
+    @test occursin("ERROR: LoadError: UndefVarError: `@bad`", outstr)
+    @test !occursin("_repl_entry", outstr)
+    @test !occursin(r"\.[/\\]client.jl", outstr)
+
+    errexpr = :(error("fail"))
+    Base.eval_user_input(errio, errexpr, false)
+    outstr = String(take!(errio))
+    @test occursin("ERROR: fail", outstr)
+    @test !occursin("_repl_entry", outstr)
+    @test !occursin(r"\.[/\\]client.jl", outstr)
+end