faa1e0f qt: test: Create at most one testing setup (MarcoFalke)

Pull request description:

  It is assumed that ideally only one BasicTestingSetup exists at any point in time for each process (due to use of globals).

  This assumption is violated in the GUI tests, as a testing setup is created as the first step of the `main` function and then (sometimes) another one for the following test cases.

  So, the gui tests create two testing setups:
  * `BasicTestingSetup` in `main` (added in fa4a04a)
  * a testing setup for individual test cases

  Avoid that by destructing the testing setup in main after creation and then move the explicit `ECC_Stop` to the only places where it is needed (before and after `apptests`).

ACKs for top commit:
  laanwj:
    code review ACK faa1e0f

Tree-SHA512: b8edceb7e2a8749e1de3ea80bc20b6fb7d4390bf366bb9817206ada3dc8669a91416f4803c22a0e6c636c514e0c858dcfe04523221f8851b10deaf472f107d82

…rites to wallet

7195fa7 test: Tool wallet test coverage for unexpected writes to wallet (Jon Atack)
3bf2b3a test: Split tool_wallet.py test into subtests (Jon Atack)
1eb13f0 test: Add log messages to test/functional/tool_wallet.py (Jon Atack)

Pull request description:

  This pull request adds test coverage in `test/functional/tool_wallet.py` to reproduce unexpected writes to the wallet as described in bitcoin#15608 and serve as a benchmark for fixing the issue:

  - Wallet tool `info` unexpectedly writes to the wallet file if the wallet file permissions are read/write.

  - Wallet tool `info` raises with "Error loading . Is wallet being used by another process?" if the wallet file permissions are read-only.

  Goals:

  1. Reproduce the reported issue, define the current unexpected behavior, and add test coverage to guide a future fix. Add debug-level logging for sanity checking and commented-out assertions to be uncommented when fixing the issue. Add the same coverage to the wallet tool create test and the getwalletinfo test as regression tests while fixing the issue.

  2. Add info log messages as there are currently none in the test file.

  3. Split the tests out to separate functions as per review feedback.

  Thanks to Marco Falke for pointing me in the right direction.

ACKs for top commit:
  laanwj:
    code review ACK 7195fa7

Tree-SHA512: 16a41cce989c8f819cf5b02c6cf8ea84653ede2738fb402f6c36cf4dc075b424dff3e2c73a1cfa1ec9c75f614675baecc71e588845a2596db06ba0957db2df7b

abdfc5e qa: Test ZMQ notification after chain reorg (João Barbosa)
aa2622a qa: Refactor ZMQ test (João Barbosa)
6bc1ff9 doc: Add note regarding ZMQ block notification (João Barbosa)

Pull request description:

Top commit has no ACKs.

Tree-SHA512: b93237adc8c84b3aa72ccc28097090eabcb006cf408083218bebf6fec703bd0de2ded80b6879e77096872e14ba9402a6d3f923b146a54d4c4e41dcb862c3e765

…s in rpc_invalidateblock

fae961d test: Establish only one connection between nodes in rpc_invalidateblock (MarcoFalke)

Pull request description:

  Headers and block sync should eventually converge to the same result, regardless of whether the peers treat each other as "inbound" or "outbound".

  `connect_nodes_bi` has been introduced as a (temporary?) workaround for bug dashpay#5113 and dashpay#5138, which has long been fixed in dashpay#5157 and dashpay#5662.

  Thus remove the `connect_nodes_bi` workaround from the rpc_invalidateblock test.

  Conveniently, this also closes bitcoin#16453. See bitcoin#16444 (comment) for rationale

ACKs for top commit:
  laanwj:
    ACK fae961d

Tree-SHA512: b3614c66a205823df73f64d19cacfbec269beb5db52ff79004d746e17d7c0dfb43ab9785fdddc97e2a76fe76286c8c605b34df3dda4a2bf5be035f01169ae89a

fa502cb test: Bump timeouts in slow running tests (MarcoFalke)

Pull request description:

  Fixes bitcoin#16794

ACKs for top commit:
  jamesob:
    ACK bitcoin@fa502cb

Tree-SHA512: 52d1a6f9febe066332cc9df40638fdc3e8aaf1990caf912073b42f2f6615879da5512533ff71b85b4865034bc30da46945d34916669068e004e68058aeb04e90

…p2p_invalid_block test.

0c62e3a New regression testing for CVE-2018-17144, CVE-2012-2459, and CVE-2010-5137. (lucash-dev)
38bfca6 Added comments referencing multiple CVEs in tests and production code. (lucash-dev)

Pull request description:

  This functional test includes two scenarios that test for regressions of vulnerabilities, but they are only briefly described. There are freely available documents explaining in detail the issues, but without explicit mentions, the developer trying to maintain the code needs an additional step of digging in commit history and PR conversations to figure it out.
  Added comments to explicitly mention  CVE-2018-17144 and CVE-2012-2459, for more complete documentation.
  This improves developer experience by making understanding the tests easier.

ACKs for top commit:
  laanwj:
    ACK 0c62e3a, checked the CVE numbers, thanks for adding documentation

Tree-SHA512: 3ee05351745193b8b959e4a25d50f25a693b2d24b0732ed53cf7d5882df40b5dd0f1877bd5c69cffb921d4a7acf9deb3cc1160b96dc730d9b5984151ad06b7c9

fadfd84 test: Remove unused connect_nodes_bi (MarcoFalke)
fa3b9ee scripted-diff: test: Replace connect_nodes_bi with connect_nodes (MarcoFalke)
faaee1e test: Use connect_nodes when connecting nodes in the test_framework (MarcoFalke)
1111bb9 test: Reformat python imports to aid scripted diff (MarcoFalke)

Pull request description:

  By default all test nodes are connected in a chain. However, instead of just a single connection between each pair of nodes, we end up with up to four connections for a "middle" node (two outbound, two inbound, from each side).

  This is generally redundant (tx and block relay should succeed with just a single connection) and confusing. For example, test timeouts after a call to `sync_` may be racy and hard to reproduce. On top of that, the test `debug.log`s are hard to read because txs and block invs may be relayed on the same connection multiple times.

  Fix this by inlining `connect_nodes_bi` in the two tests that need it, and then replace it with a single `connect_nodes` in all other tests.

  Historic background:

  `connect_nodes_bi` has been introduced as a (temporary?) workaround for bug dashpay#5113 and dashpay#5138, which has long been fixed in dashpay#5157 and dashpay#5662.

ACKs for top commit:
  laanwj:
    ACK fadfd84
  jonasschnelli:
    utACK fadfd84 - more of less a cleanup PR.
  promag:
    Tested ACK fadfd84, ran extended tests.

Tree-SHA512: 2d027a8fd150749c071b64438a0a78ec922178628a7dbb89fd1212b0fa34febd451798c940101155d3617c0426c2c4865174147709894f1f1bb6cfa336aa7e24

… util.py

96299a9 Test: Move common function assert_approx() into util.py (fridokus)

Pull request description:

  To reduce code duplication, move `assert_approx` into common framework `util.py`.

  `assert_approx()` is used in two functional tests.

ACKs for top commit:
  theStack:
    ACK 96299a9
  practicalswift:
    ACK 96299a9 -- DRY is good and diff looks correct
  fanquake:
    ACK 96299a9 - thanks for contributing 🍻

Tree-SHA512: 8e9d397222c49536c7b3d6d0756cc5af17113e5af8707ac48a500fff1811167fb2e03f3c0445b0b9e80f34935f4d57cfb935c4790f6f5463a32a67df5f736939

fa69588 test: Make PORT_MIN in test runner configurable (MarcoFalke)

Pull request description:

  This is needed when some ports in the port range are used by other processes. Note that simply assigning the ports dynamically does not work:

  * We spin up several nodes per test (each node gets its own port)
  * We run several tests in parallel

  So to avoid nodes from different tests colliding on ports, the port assignment must be deterministic (can not be dynamic).

  Fixes: bitcoin#10869

ACKs for top commit:
  practicalswift:
    ACK fa69588 -- diff looks correct
  promag:
    ACK fa69588.

Tree-SHA512: e79adb015e7de79064e2d14336c38bc9672bd779ad6c52917721897e73f617c39d32c068a369c26670002a6c4ab95a71ef3a6878ebdd9710e02f410e2f7bcd14

43e7d57 doc: Improve test READMEs (Fabian Jahr)

Pull request description:

  General improvements on READMEs for unit tests and functional tests:
  - Give unit test readme a headline
  - Move general information on `src/test` folder to the top
  - Add information on logging and debugging unit tests
  - Improve debugging and logging information in functional testing
  - Include all available log levels in functional tests

ACKs for top commit:
  laanwj:
    ACK 43e7d57

Tree-SHA512: 22b27644992ba5d99a885cd51b7a474806714396fcea1fd2d6285e41bdf3b28835ad8c81449099e3ee15a63d57b3ab9acb89c425d9855ed1d9b4af21db35ab03