Set Thread.report_on_exception=true by default to report exceptions in Threads

* [Feature #14143] [ruby-core:83979]
* vm.c (vm_init2): Set Thread.report_on_exception to true.
* thread.c (thread_start_func_2): Add indication the message is caused
  by report_on_exception = true.
* spec/ruby: Specify the new behavior.
* test/ruby/test_thread.rb: Adapt and improve tests for
  Thread.report_on_exception and Thread#report_on_exception.
* test/ruby/test_thread.rb, test/ruby/test_exception.rb: Unset
  report_on_exception for tests expecting no extra output.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@61183 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 2 deletions

diff --git a/spec/ruby/core/thread/report_on_exception_spec.rb b/spec/ruby/core/thread/report_on_exception_spec.rb
index 4128dad470..74b7984a32 100644
--- a/spec/ruby/core/thread/report_on_exception_spec.rb
+++ b/spec/ruby/core/thread/report_on_exception_spec.rb
@@ -2,8 +2,16 @@ require File.expand_path('../../../spec_helper', __FILE__)
 
 ruby_version_is "2.4" do
   describe "Thread.report_on_exception" do
-    it "defaults to false" do
-      ruby_exe("p Thread.report_on_exception").should == "false\n"
+    ruby_version_is "2.4"..."2.5" do
+      it "defaults to false" do
+        ruby_exe("p Thread.report_on_exception").should == "false\n"
+      end
+    end
+
+    ruby_version_is "2.5" do
+      it "defaults to true" do
+        ruby_exe("p Thread.report_on_exception").should == "true\n"
+      end
     end
   end