Don't show string concatenation error hint with zero arg + (#55749)

Closes #55745
JuliaLang · Sep 12, 2024 · 492ef6e · 492ef6e
1 parent 00fce67
commit 492ef6e
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diff --git a/base/errorshow.jl b/base/errorshow.jl
@@ -1067,7 +1067,7 @@ Experimental.register_error_hint(nonsetable_type_hint_handler, MethodError)
 # (probably attempting concatenation)
 function string_concatenation_hint_handler(io, ex, arg_types, kwargs)
     @nospecialize
-    if (ex.f === +) && all(i -> i <: AbstractString, arg_types)
+    if (ex.f === +) && !isempty(arg_types) && all(i -> i <: AbstractString, arg_types)
         print(io, "\nString concatenation is performed with ")
         printstyled(io, "*", color=:cyan)
         print(io, " (See also: https://docs.julialang.org/en/v1/manual/strings/#man-concatenation).")

diff --git a/test/errorshow.jl b/test/errorshow.jl
@@ -1079,6 +1079,12 @@ let err_str
     @test occursin("String concatenation is performed with *", err_str)
 end
 
+# https://github.com/JuliaLang/julia/issues/55745
+let err_str
+    err_str = @except_str +() MethodError
+    @test !occursin("String concatenation is performed with *", err_str)
+end
+
 struct MissingLength; end
 struct MissingSize; end
 Base.IteratorSize(::Type{MissingSize}) = Base.HasShape{2}()