Return EXIT_FAILURE on post-init fatal errors

It seems odd to return `EXIT_SUCCESS` when the node aborted
execution due a fatal internal error or any post-init problem
that triggers an unrequested shutdown.

e.g. blocks or coins db I/O errors, disconnect block failure,
failure during thread import (external blocks loading process
error), among others.

Co-authored-by: Ryan Ofsky <ryan@ofsky.org>

1 files changed, 11 insertions, 5 deletions

diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 51bd697e81..4466bd544f 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -365,7 +365,7 @@ class TestNode():
         if wait_until_stopped:
             self.wait_until_stopped()
 
-    def is_node_stopped(self):
+    def is_node_stopped(self, expected_ret_code=None):
         """Checks whether the node has stopped.
 
         Returns True if the node has stopped. False otherwise.
@@ -377,8 +377,13 @@ class TestNode():
             return False
 
         # process has stopped. Assert that it didn't return an error code.
-        assert return_code == 0, self._node_msg(
-            "Node returned non-zero exit code (%d) when stopping" % return_code)
+        # unless 'expected_ret_code' is provided.
+        if expected_ret_code is not None:
+            assert return_code == expected_ret_code, self._node_msg(
+                "Node returned unexpected exit code (%d) vs (%d) when stopping" % (return_code, expected_ret_code))
+        else:
+            assert return_code == 0, self._node_msg(
+                "Node returned non-zero exit code (%d) when stopping" % return_code)
         self.running = False
         self.process = None
         self.rpc_connected = False
@@ -386,8 +391,9 @@ class TestNode():
         self.log.debug("Node stopped")
         return True
 
-    def wait_until_stopped(self, timeout=BITCOIND_PROC_WAIT_TIMEOUT):
-        wait_until_helper(self.is_node_stopped, timeout=timeout, timeout_factor=self.timeout_factor)
+    def wait_until_stopped(self, timeout=BITCOIND_PROC_WAIT_TIMEOUT, expect_error=False):
+        expected_ret_code = 1 if expect_error else None  # Whether node shutdown return EXIT_FAILURE or EXIT_SUCCESS
+        wait_until_helper(lambda: self.is_node_stopped(expected_ret_code=expected_ret_code), timeout=timeout, timeout_factor=self.timeout_factor)
 
     def replace_in_config(self, replacements):
         """