Add back the empty-credentials test but as test_broken

on windows with libgit2 >= v0.26

Author: tkelman

test/libgit2-online.jl

@@ -30,5 +30,24 @@ mktempdir() do dir
                 @test ex.code == LibGit2.Error.EAUTH
             end
         end
+
+        @testset "with empty credentials" begin
+            try
+                repo_path = joinpath(dir, "Example3")
+                # credentials are required because github tries to authenticate on unknown repo
+                cred = LibGit2.UserPasswordCredentials("","") # empty credentials cause authentication error
+                LibGit2.clone(repo_url*randstring(10), repo_path, payload=Nullable(cred))
+                error("unexpected")
+            catch ex
+                @test isa(ex, LibGit2.Error.GitError)
+                if is_windows() && LibGit2.version() >= v"0.26.0"
+                    # see #22681 and https://github.com/libgit2/libgit2/pull/4055
+                    @test_broken ex.code == LibGit2.Error.EAUTH
+                    @test ex.code == LibGit2.Error.ERROR
+                else
+                    @test ex.code == LibGit2.Error.EAUTH
+                end
+            end
+        end
     end
 end