Only warn in helpmode on successful nonpublic access (#51346)

Author: LilithHafner

stdlib/REPL/src/docview.jl

@@ -166,7 +166,7 @@ struct Logged{F}
     collection::Set{Pair{Module,Symbol}}
 end
 function (la::Logged)(m::Module, s::Symbol)
-    m !== la.mod && !Base.ispublic(m, s) && push!(la.collection, m => s)
+    m !== la.mod && Base.isdefined(m, s) && !Base.ispublic(m, s) && push!(la.collection, m => s)
     la.f(m, s)
 end
 (la::Logged)(args...) = la.f(args...)

stdlib/REPL/test/docview.jl

@@ -132,3 +132,6 @@ module InternalWarningsTests
         @test docstring("A.B3") == "No docstring or readme file found for public module `$(@__MODULE__).A.B3`.\n\nModule does not have any public names.\n"
     end
 end
+
+# Issue #51344, don't print "internal binding" warning for non-existent bindings.
+@test string(eval(REPL.helpmode("Base.no_such_symbol"))) == "No documentation found.\n\nBinding `Base.no_such_symbol` does not exist.\n"