Handle Process.kill on the current PID correctly if no handler is registered

Author: eregon

spec/tags/core/signal/trap_tags.txt

@@ -6,4 +6,3 @@ slow:Signal.trap the special EXIT signal code can unset the handler
 slow:Signal.trap returns 'DEFAULT' for the initial SIGINT handler
 slow:Signal.trap accepts 'SYSTEM_DEFAULT' and uses the OS handler for SIGPIPE
 slow:Signal.trap allows to register a handler for all known signals, except reserved signals for which it raises ArgumentError
-fails:Signal.trap registers an handler doing nothing with :IGNORE

src/main/java/org/truffleruby/core/ProcessNodes.java

@@ -17,7 +17,6 @@
 import org.truffleruby.builtins.CoreClass;
 import org.truffleruby.builtins.Primitive;
 import org.truffleruby.builtins.PrimitiveArrayArgumentsNode;
-import org.truffleruby.language.control.RaiseException;
 import sun.misc.Signal;
 
 @CoreClass("Process")
@@ -54,7 +53,8 @@ public int raise(DynamicObject signalName) {
             try {
                 Signal.raise(signal);
             } catch (IllegalArgumentException e) {
-                throw new RaiseException(getContext(), coreExceptions().argumentError(e.getMessage(), this));
+                // Java does not know the handler, fallback to using kill()
+                return -1;
             }
             return 1;
         }

src/main/ruby/truffleruby/core/process.rb

@@ -376,7 +376,11 @@ def self.kill(signal, *pids)
 
       if pid == Process.pid && signal != 0
         signal_name = Signal::Numbers[signal].to_sym
-        Truffle.invoke_primitive :process_kill_raise, signal_name
+        result = Truffle.invoke_primitive :process_kill_raise, signal_name
+        if result == -1 # Try kill() if the java Signal.raise() failed
+          result = Truffle::POSIX.kill(pid, signal)
+          Errno.handle if result == -1
+        end
       else
         pid = -pid if use_process_group
         result = Truffle::POSIX.kill(pid, signal)