Merge bitcoin/bitcoin#24789: init, index: disallow indexes when running reindex-chainstate

dac44fc06ff9938d070aa5221d106a7f31da9d81 init: disallow reindex-chainstate with optional indexes (Martin Zumsande)
62e14285f95d4ecb9528813acca975640dd7c598 doc: Add note that -reindex will rebuild optional indexes (Martin Zumsande)

Pull request description:

  When started together with `-reindex-chainstate`, currently coinstatsindex gets corrupted and the blockfilterindex flatfiles duplicated. See the OP of #24630 for more a more detailed explanation on why this happens.

  This is an alternative to #24630 which does not wipe and rebuild the indexes but returns an `InitError` when they are activated, thus requiring the user to deactivate them temporarily until the `-reindex-chainstate` run is finished.

  This also disallows `-reindex-chainstate` in combination with `-txindex`, which is not leading to corruption, but currently still rebuilds the index unnecessarily and unexpectedly.

  As a long-term goal, it would be desirable to have the indexes tolerate `reindex-chainstate` by ignoring their `BlockConnected` notifications (there is discussion in #24630 about this) or possibly move `reindex-chainstate` option  into a `bitcoin-chainstate` executable, which could also solve the problem. But these would be larger projects - until then, it might be better to disallow the interaction than having corrupted indexes.

  The first commit adjusts the `-reindex` doc to mention that this option does rebuild all active indexes.

ACKs for top commit:
  ryanofsky:
    Code review ACK dac44fc06ff9938d070aa5221d106a7f31da9d81. Just fixed IsArgSet call and edited error messages since last review

Tree-SHA512: c1abf7d350648ae227c3fd6c95d9a54c3bac9de70915275dea1c87cca6d9a76a056c0e306d95ef8cfe4df1f8525b418e0e7a4f52ded3be464041c0dc297f8930

2 files changed, 20 insertions, 0 deletions

diff --git a/test/functional/feature_coinstatsindex.py b/test/functional/feature_coinstatsindex.py
index f865661894..251aa2114b 100755
--- a/test/functional/feature_coinstatsindex.py
+++ b/test/functional/feature_coinstatsindex.py
@@ -223,6 +223,20 @@ class CoinStatsIndexTest(BitcoinTestFramework):
         res10 = index_node.gettxoutsetinfo('muhash')
         assert(res8['txouts'] < res10['txouts'])
 
+        self.log.info("Test that the index works with -reindex")
+
+        self.restart_node(1, extra_args=["-coinstatsindex", "-reindex"])
+        res11 = index_node.gettxoutsetinfo('muhash')
+        assert_equal(res11, res10)
+
+        self.log.info("Test that -reindex-chainstate is disallowed with coinstatsindex")
+
+        self.nodes[1].assert_start_raises_init_error(
+            expected_msg='Error: -reindex-chainstate option is not compatible with -coinstatsindex. '
+            'Please temporarily disable coinstatsindex while using -reindex-chainstate, or replace -reindex-chainstate with -reindex to fully rebuild all indexes.',
+            extra_args=['-coinstatsindex', '-reindex-chainstate'],
+        )
+
     def _test_use_index_option(self):
         self.log.info("Test use_index option for nodes running the index")
 
diff --git a/test/functional/p2p_blockfilters.py b/test/functional/p2p_blockfilters.py
index e45cef65bd..2ffc825acd 100755
--- a/test/functional/p2p_blockfilters.py
+++ b/test/functional/p2p_blockfilters.py
@@ -250,6 +250,12 @@ class CompactFiltersTest(BitcoinTestFramework):
         msg = "Error: Cannot set -peerblockfilters without -blockfilterindex."
         self.nodes[0].assert_start_raises_init_error(expected_msg=msg)
 
+        self.log.info("Test -blockfilterindex with -reindex-chainstate raises an error")
+        self.nodes[0].assert_start_raises_init_error(
+            expected_msg='Error: -reindex-chainstate option is not compatible with -blockfilterindex. '
+            'Please temporarily disable blockfilterindex while using -reindex-chainstate, or replace -reindex-chainstate with -reindex to fully rebuild all indexes.',
+            extra_args=['-blockfilterindex', '-reindex-chainstate'],
+        )
 
 def compute_last_header(prev_header, hashes):
     """Compute the last filter header from a starting header and a sequence of filter hashes."""