signal.c: EINVAL is a failure

* signal.c (ruby_signal): although "EINVAL from sigaction(2) is
  not a bug", but even it is a failure.  pointed at toRuby/guRuby
  in RubyHiroba.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47657 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 33 insertions, 9 deletions

diff --git a/ChangeLog b/ChangeLog
index 57b56974d6..a8c662967a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Sep 21 11:03:32 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* signal.c (ruby_signal): although "EINVAL from sigaction(2) is
+	  not a bug", but even it is a failure.  pointed at toRuby/guRuby
+	  in RubyHiroba.
+
 Sat Sep 20 03:00:26 2014  Masaki Matsushita <glass.saga@gmail.com>
 
 	* lib/tempfile.rb: define parameters appropriately and some
diff --git a/signal.c b/signal.c
index 075738576b..296afdd966 100644
--- a/signal.c
+++ b/signal.c
@@ -258,6 +258,18 @@ ruby_signal_name(int no)
     return signo2signm(no);
 }
 
+static VALUE
+rb_signo2signm(int signo)
+{
+    const char *const signm = signo2signm(signo);
+    if (signm) {
+	return rb_sprintf("SIG%s", signm);
+    }
+    else {
+	return rb_sprintf("SIG%u", signo);
+    }
+}
+
 /*
  * call-seq:
  *    SignalException.new(sig_name)              ->  signal_exception
@@ -290,13 +302,7 @@ esignal_init(int argc, VALUE *argv, VALUE self)
 	    sig = argv[1];
 	}
 	else {
-	    signm = signo2signm(signo);
-	    if (signm) {
-		sig = rb_sprintf("SIG%s", signm);
-	    }
-	    else {
-		sig = rb_sprintf("SIG%u", signo);
-	    }
+	    sig = rb_signo2signm(signo);
 	}
     }
     else {
@@ -600,8 +606,12 @@ ruby_signal(int signum, sighandler_t handler)
     }
     (void)VALGRIND_MAKE_MEM_DEFINED(&old, sizeof(old));
     if (sigaction(signum, &sigact, &old) < 0) {
-	if (errno != 0 && errno != EINVAL) {
-	    rb_bug_errno("sigaction", errno);
+	int e = errno;
+	if (e == EINVAL) {
+	    rb_syserr_fail_str(e, rb_signo2signm(signum));
+	}
+	else if (e != 0) {
+	    rb_bug_errno("sigaction", e);
 	}
     }
     if (old.sa_flags & SA_SIGINFO)
diff --git a/test/ruby/test_signal.rb b/test/ruby/test_signal.rb
index 251a12db17..e4cca022b3 100644
--- a/test/ruby/test_signal.rb
+++ b/test/ruby/test_signal.rb
@@ -169,6 +169,14 @@ class TestSignal < Test::Unit::TestCase
     end
   end if Process.respond_to?(:kill)
 
+  %w"KILL STOP".each do |sig|
+    if Signal.list.key?(sig)
+      define_method("test_trap_uncatchable_#{sig}") do
+        assert_raise(Errno::EINVAL, "SIG#{sig} is not allowed to be caught") { Signal.trap(sig) {} }
+      end
+    end
+  end
+
   def test_kill_immediately_before_termination
     Signal.list[sig = "USR1"] or sig = "INT"
     assert_in_out_err(["-e", <<-"end;"], "", %w"foo")