From 934c81c9d49ea22021791f666e9088e11bd0ccf8 Mon Sep 17 00:00:00 2001
From: Kyrylo Silin <silin@kyrylo.org>
Date: Fri, 15 Jan 2016 17:14:49 +0200
Subject: [PATCH] nested_exception: fix backtrace parsing

While working on https://github.com/airbrake/airbrake/pull/479 I
stumbled upon a bug in Airbrake Ruby where the default filter couldn't
process error payload because `:backtrace` was `nil`. Returning an
empty array in case the real backtrace is missing seems to be a more
secure approach.
---
 CHANGELOG.md                                           | 4 +++-
 lib/airbrake-ruby/backtrace.rb                         | 2 ++
 lib/airbrake-ruby/nested_exception.rb                  | 7 +------
 spec/{nested_exception.rb => nested_exception_spec.rb} | 4 ++--
 4 files changed, 8 insertions(+), 9 deletions(-)
 rename spec/{nested_exception.rb => nested_exception_spec.rb} (95%)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 924c217e..ac723153 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,9 @@ Airbrake Ruby Changelog
 ### master
 
 * Improved parsing of backtraces
-  ([#25](https://github.com/airbrake/airbrake-ruby/pull/25))
+  ([#25](https://github.com/airbrake/airbrake-ruby/pull/25),
+  [#29](https://github.com/airbrake/airbrake-ruby/pull/29),
+  [#30](https://github.com/airbrake/airbrake-ruby/pull/30))
 * Made sure that generated notices always have a backtrace
   ([#21](https://github.com/airbrake/airbrake-ruby/pull/21))
 * Made the asynchronous delivery mechanism more robust
diff --git a/lib/airbrake-ruby/backtrace.rb b/lib/airbrake-ruby/backtrace.rb
index 12b496c2..b3eefef2 100644
--- a/lib/airbrake-ruby/backtrace.rb
+++ b/lib/airbrake-ruby/backtrace.rb
@@ -51,6 +51,8 @@ module Backtrace
     #   parse
     # @return [Array<Hash{Symbol=>String,Integer}>] the parsed backtrace
     def self.parse(exception)
+      return [] if exception.backtrace.nil? || exception.backtrace.none?
+
       regexp = if java_exception?(exception)
                  JAVA_STACKFRAME_REGEXP
                else
diff --git a/lib/airbrake-ruby/nested_exception.rb b/lib/airbrake-ruby/nested_exception.rb
index 5d668a31..4b5f3f9e 100644
--- a/lib/airbrake-ruby/nested_exception.rb
+++ b/lib/airbrake-ruby/nested_exception.rb
@@ -16,7 +16,7 @@ def as_json
       unwind_exceptions.map do |exception|
         { type: exception.class.name,
           message: exception.message,
-          backtrace: parse_backtrace(exception) }
+          backtrace: Backtrace.parse(exception) }
       end
     end
 
@@ -33,10 +33,5 @@ def unwind_exceptions
 
       exception_list
     end
-
-    def parse_backtrace(exception)
-      return if exception.backtrace.nil? || exception.backtrace.none?
-      Backtrace.parse(exception)
-    end
   end
 end
diff --git a/spec/nested_exception.rb b/spec/nested_exception_spec.rb
similarity index 95%
rename from spec/nested_exception.rb
rename to spec/nested_exception_spec.rb
index 1602ee33..05694faa 100644
--- a/spec/nested_exception.rb
+++ b/spec/nested_exception_spec.rb
@@ -68,8 +68,8 @@
           exceptions = nested_exception.as_json
 
           expect(exceptions.size).to eq(2)
-          expect(exceptions[0][:backtrace]).to be_nil
-          expect(exceptions[1][:backtrace]).to be_nil
+          expect(exceptions[0][:backtrace]).to be_empty
+          expect(exceptions[1][:backtrace]).to be_empty
         end
       end
     end