erts: Change default of erl_crash.dump

* Create an erl_crash.dump if no heart exists
  and no ERL_CRASH_DUMP_SECONDS is set (behaviour changed)
* Don't create an erl_crash.dump if heart do exists
  and no ERL_CRASH_DUMP_SECONDS is set (behaviour not changed)

This changes the behaviour back to the R15B02 default considering
if a beam was running with no heart.

The motivation is that we want a fast heart to fast restart erlang if
it crashes but to be able to get non-truncated erl_crash.dumps via
setting ERL_CRASH_DUMP_SECONDS if we so desire.

1 files changed, 5 insertions, 2 deletions

diff --git a/erts/emulator/sys/win32/sys.c b/erts/emulator/sys/win32/sys.c
index 50f6219374..578536ed08 100755
--- a/erts/emulator/sys/win32/sys.c
+++ b/erts/emulator/sys/win32/sys.c
@@ -255,8 +255,7 @@ void erl_sys_args(int* argc, char** argv)
 #endif
 }
 
-void
-erts_sys_prepare_crash_dump(int secs)
+int erts_sys_prepare_crash_dump(int secs)
 {
     Port *heart_port;
     Eterm heap[3];
@@ -271,10 +270,14 @@ erts_sys_prepare_crash_dump(int secs)
 
 	/* send to heart port, CMD = 8, i.e. prepare crash dump =o */
 	erts_write_to_port(NIL, heart_port, list);
+
+	return 1;
     }
 
     /* Windows - free file descriptors are hopefully available */
     /* Alarm not used on windows */
+
+    return 0;
 }
 
 static void