Merge bitcoin/bitcoin#27708: Return EXIT_FAILURE on post-init fatal errors

61c569ab6069d04079a0831468eb713983919636 refactor: decouple early return commands from AppInit (furszy)
4927167f855f8ed3bbf6d2766f61229f742e632a gui: return EXIT_FAILURE on post-init fatal errors (furszy)
3b2c61e8198bcefb1c2343caff1d705951026cc4 Return EXIT_FAILURE on post-init fatal errors (furszy)
3c06926cf21dcca3074ef51506f556b2286c299b refactor: index: use `AbortNode` in fatal error helper (Sebastian Falbesoner)
9ddf7e03a35592617a016418fd320cc93c8d1abd move ThreadImport ABC error to use AbortNode (furszy)

Pull request description:

  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.

ACKs for top commit:
  TheCharlatan:
    ACK 61c569ab6069d04079a0831468eb713983919636
  ryanofsky:
    Code review ACK 61c569ab6069d04079a0831468eb713983919636
  pinheadmz:
    ACK 61c569ab6069d04079a0831468eb713983919636
  theStack:
    Code-review ACK 61c569ab6069d04079a0831468eb713983919636

Tree-SHA512: 18a59c3acc1c6d12cbc74a20a401e89659740c6477fccb59070c9f97922dfe588468e9e5eef56c5f395762187c34179a5e3954aa5b844787fa13da2e666c63d3

2 files changed, 12 insertions, 6 deletions

diff --git a/test/functional/feature_abortnode.py b/test/functional/feature_abortnode.py
index fa1bb6506a..586722aa65 100755
--- a/test/functional/feature_abortnode.py
+++ b/test/functional/feature_abortnode.py
@@ -40,7 +40,7 @@ class AbortNodeTest(BitcoinTestFramework):
 
             # Check that node0 aborted
             self.log.info("Waiting for crash")
-            self.nodes[0].wait_until_stopped(timeout=5)
+            self.nodes[0].wait_until_stopped(timeout=5, expect_error=True)
         self.log.info("Node crashed - now verifying restart fails")
         self.nodes[0].assert_start_raises_init_error()
 
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):
         """