From bca9991f5cb72538a6a028db71060b764dc87236 Mon Sep 17 00:00:00 2001
From: Jeff Kreeftmeijer <jeffkreeftmeijer@gmail.com>
Date: Fri, 13 Jan 2017 12:52:13 +0100
Subject: [PATCH] Appsignal.Transaction.set_error/4 handles unformatted
 stacktraces (#72)

* Transaction.set_error/4 handles unformatted stacktraces

* Don't format_stack/1 in Phoenix.submit_http_error/5
---
 lib/appsignal/phoenix.ex              | 2 +-
 lib/appsignal/transaction.ex          | 8 ++++++++
 test/transaction/transaction_test.exs | 7 +++++++
 3 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/lib/appsignal/phoenix.ex b/lib/appsignal/phoenix.ex
index 7075d2421..9a9c98141 100644
--- a/lib/appsignal/phoenix.ex
+++ b/lib/appsignal/phoenix.ex
@@ -61,7 +61,7 @@ defmodule Appsignal.Phoenix do
 
   @doc false
   def submit_http_error(reason, message, stack, transaction, conn) do
-    Transaction.set_error(transaction, reason, message, ErrorHandler.format_stack(stack))
+    Transaction.set_error(transaction, reason, message, stack)
     Transaction.try_set_action(transaction, conn)
     if Transaction.finish(transaction) == :sample do
       Transaction.set_request_metadata(transaction, conn)
diff --git a/lib/appsignal/transaction.ex b/lib/appsignal/transaction.ex
index c87d1aea7..c207fac3d 100644
--- a/lib/appsignal/transaction.ex
+++ b/lib/appsignal/transaction.ex
@@ -171,6 +171,14 @@ defmodule Appsignal.Transaction do
   """
   @spec set_error(Transaction.t | nil, String.t, String.t, any) :: Transaction.t
   def set_error(nil, _name, _message, _backtrace), do: nil
+  def set_error(%Transaction{} = transaction, name, message, [h|_] = backtrace) when is_tuple(h) do
+    set_error(
+      transaction,
+      name,
+      message,
+      Appsignal.ErrorHandler.format_stack(backtrace)
+    )
+  end
   def set_error(%Transaction{} = transaction, name, message, backtrace) do
     name = name |> String.split_at(@max_name_size) |> elem(0)
     backtrace_data = Appsignal.Utils.DataEncoder.encode(backtrace)
diff --git a/test/transaction/transaction_test.exs b/test/transaction/transaction_test.exs
index 3d5e6bb5b..d16bcd11e 100644
--- a/test/transaction/transaction_test.exs
+++ b/test/transaction/transaction_test.exs
@@ -93,4 +93,11 @@ defmodule AppsignalTransactionTest do
     assert ^transaction = Transaction.start_event(transaction)
     assert ^transaction = Transaction.finish_event(transaction, "phoenix_controller_render", "phoenix_controller_render", %{format: "html", template: "index.html"}, 0)
   end
+
+  test "handles unformatted stacktraces" do
+    transaction = Transaction.start("test1", :http_request)
+    assert ^transaction = Transaction.set_error(transaction, "Error", "error message", System.stacktrace)
+    assert ^transaction = Transaction.start_event(transaction)
+    assert ^transaction = Transaction.finish_event(transaction, "phoenix_controller_render", "phoenix_controller_render", %{format: "html", template: "index.html"}, 0)
+  end
 end