Fix eltype() and pointer() of Cstring (JuliaLang#31471)

Fixes JuliaLang#31381
halleysfifthinc · Mar 28, 2019 · dbe50f9 · dbe50f9
1 parent c0ebd97
commit dbe50f9
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Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/base/c.jl b/base/c.jl
@@ -183,7 +183,7 @@ Calling [`Ref(array[, index])`](@ref Ref) is generally preferable to this functi
 """
 function pointer end
 
-pointer(p::Cstring) = convert(Ptr{UInt8}, p)
+pointer(p::Cstring) = convert(Ptr{Cchar}, p)
 pointer(p::Cwstring) = convert(Ptr{Cwchar_t}, p)
 
 # comparisons against pointers (mainly to support `cstr==C_NULL`)
@@ -203,7 +203,7 @@ function cconvert(::Type{Cwstring}, s::AbstractString)
  return v
 end
 
-eltype(::Type{Cstring}) = UInt8
+eltype(::Type{Cstring}) = Cchar
 eltype(::Type{Cwstring}) = Cwchar_t
 
 containsnul(p::Ptr, len) =

diff --git a/test/strings/types.jl b/test/strings/types.jl
@@ -323,3 +323,11 @@ let
  @test cstring != C_NULL
  @test C_NULL != cstring
 end
+
+# issue #31381: eltype(Cstring) != Cchar
+let
+ s = Cstring(C_NULL)
+ @test eltype(Cstring) == Cchar
+ @test eltype(s) == Cchar
+ @test pointer(s) isa Ptr{Cchar}
+end