use correct variable in windowserror description (#34067)

Author: vtjnash

base/error.jl

@@ -179,7 +179,7 @@ end
 Like [`systemerror`](@ref), but for Windows API functions that use [`GetLastError`](@ref Base.Libc.GetLastError) to
 return an error code instead of setting [`errno`](@ref Base.Libc.errno).
 """
-windowserror(p, b::Bool; extrainfo=nothing) = b ? windowserror(b, extrainfo=extrainfo) : nothing
+windowserror(p, b::Bool; extrainfo=nothing) = b ? windowserror(p, extrainfo=extrainfo) : nothing
 windowserror(p, code::UInt32=Libc.GetLastError(); extrainfo=nothing) = throw(Main.Base.SystemError(string(p), 0, WindowsErrorInfo(code, extrainfo)))
 
 

base/libc.jl

@@ -313,14 +313,15 @@ function FormatMessage end
 if Sys.iswindows()
     GetLastError() = ccall(:GetLastError, stdcall, UInt32, ())
 
-    function FormatMessage(e=GetLastError())
+    FormatMessage(e) = FormatMessage(UInt32(e))
+    function FormatMessage(e::UInt32=GetLastError())
         FORMAT_MESSAGE_ALLOCATE_BUFFER = UInt32(0x100)
         FORMAT_MESSAGE_FROM_SYSTEM = UInt32(0x1000)
         FORMAT_MESSAGE_IGNORE_INSERTS = UInt32(0x200)
         FORMAT_MESSAGE_MAX_WIDTH_MASK = UInt32(0xFF)
         lpMsgBuf = Ref{Ptr{UInt16}}()
         lpMsgBuf[] = 0
-        len = ccall(:FormatMessageW, stdcall, UInt32, (Cint, Ptr{Cvoid}, Cint, Cint, Ptr{Ptr{UInt16}}, Cint, Ptr{Cvoid}),
+        len = ccall(:FormatMessageW, stdcall, UInt32, (UInt32, Ptr{Cvoid}, UInt32, UInt32, Ptr{Ptr{UInt16}}, UInt32, Ptr{Cvoid}),
                     FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_MAX_WIDTH_MASK,
                     C_NULL, e, 0, lpMsgBuf, 0, C_NULL)
         p = lpMsgBuf[]

test/errorshow.jl

@@ -5,6 +5,50 @@ using Random, LinearAlgebra
 # For curmod_*
 include("testenv.jl")
 
+
+@testset "SystemError" begin
+    err = try; systemerror("reason", Cint(0)); false; catch ex; ex; end::SystemError
+    errs = sprint(Base.showerror, err)
+    @test startswith(errs, "SystemError: reason: ")
+
+    err = try; systemerror("reason", Cint(0), extrainfo="addend"); false; catch ex; ex; end::SystemError
+    errs = sprint(Base.showerror, err)
+    @test startswith(errs, "SystemError (with addend): reason: ")
+
+    err = try
+            Libc.errno(0xc0ffee)
+            systemerror("reason", true)
+            false
+        catch ex
+            ex
+        end::SystemError
+    errs = sprint(Base.showerror, err)
+    @test startswith(errs, "SystemError: reason: ")
+
+    err = try; Base.windowserror("reason", UInt32(0)); false; catch ex; ex; end::SystemError
+    errs = sprint(Base.showerror, err)
+    @test startswith(errs, Sys.iswindows() ? "SystemError: reason: " :
+        "SystemError (with Base.WindowsErrorInfo(0x00000000, nothing)): reason: ")
+
+    err = try; Base.windowserror("reason", UInt32(0); extrainfo="addend"); false; catch ex; ex; end::SystemError
+    errs = sprint(Base.showerror, err)
+    @test startswith(errs, Sys.iswindows() ? "SystemError (with addend): reason: " :
+        "SystemError (with Base.WindowsErrorInfo(0x00000000, \"addend\")): reason: ")
+
+    @static if Sys.iswindows()
+        err = try
+                ccall(:SetLastError, stdcall, Cvoid, (UInt32,), 0x00000000)
+                Base.windowserror("reason", true)
+                false
+            catch ex
+                ex
+            end::SystemError
+        errs = sprint(Base.showerror, err)
+        @test startswith(errs, "SystemError: reason: ")
+    end
+end
+
+
 cfile = " at $(@__FILE__):"
 c1line = @__LINE__() + 1
 method_c1(x::Float64, s::AbstractString...) = true
@@ -593,4 +637,4 @@ for (func,str) in ((TestMethodShadow.:+,":+"), (TestMethodShadow.:(==),":(==)"),
        e
     end::MethodError
     @test occursin("You may have intended to import Base.$str", sprint(Base.showerror, ex))
-end
+end