20 files changed, 239 insertions, 150 deletions
diff --git a/test/README.md b/test/README.md
index b5cbe1aff3..a6fb9c9d73 100644
--- a/test/README.md
+++ b/test/README.md
@@ -175,7 +175,8 @@ cat /tmp/user/1000/testo9vsdjo3/node1/regtest/bitcoind.pid
 gdb /home/example/bitcoind <pid>
 ```
 
-Note: gdb attach step may require `sudo`
+Note: gdb attach step may require ptrace_scope to be modified, or `sudo` preceding the `gdb`.
+See this link for considerations: https://www.kernel.org/doc/Documentation/security/Yama.txt
 
 ### Util tests
 
diff --git a/test/functional/README.md b/test/functional/README.md
index d40052ac93..628c77eb11 100644
--- a/test/functional/README.md
+++ b/test/functional/README.md
@@ -20,9 +20,13 @@ don't have test cases for.
 - Where possible, try to adhere to [PEP-8 guidelines](https://www.python.org/dev/peps/pep-0008/)
 - Use a python linter like flake8 before submitting PRs to catch common style
   nits (eg trailing whitespace, unused imports, etc)
+- The oldest supported Python version is specified in [doc/dependencies.md](/doc/dependencies.md).
+  Consider using [pyenv](https://github.com/pyenv/pyenv), which checks [.python-version](/.python-version),
+  to prevent accidentally introducing modern syntax from an unsupported Python version.
+  The Travis linter also checks this, but [possibly not in all cases](https://github.com/bitcoin/bitcoin/pull/14884#discussion_r239585126).
 - See [the python lint script](/test/lint/lint-python.sh) that checks for violations that
   could lead to bugs and issues in the test code.
-- Avoid wildcard imports where possible
+- Avoid wildcard imports
 - Use a module-level docstring to describe what the test is testing, and how it
   is testing it.
 - When subclassing the BitcoinTestFramwork, place overrides for the
diff --git a/test/functional/example_test.py b/test/functional/example_test.py
index be3544ee74..f367e4fca8 100755
--- a/test/functional/example_test.py
+++ b/test/functional/example_test.py
@@ -13,7 +13,7 @@ is testing and *how* it's being tested
 # libraries then local imports).
 from collections import defaultdict
 
-# Avoid wildcard * imports if possible
+# Avoid wildcard * imports
 from test_framework.blocktools import (create_block, create_coinbase)
 from test_framework.messages import CInv
 from test_framework.mininode import (
diff --git a/test/functional/feature_blocksdir.py b/test/functional/feature_blocksdir.py
index c170f510c8..3a4889bbe9 100755
--- a/test/functional/feature_blocksdir.py
+++ b/test/functional/feature_blocksdir.py
@@ -18,6 +18,8 @@ class BlocksdirTest(BitcoinTestFramework):
 
     def run_test(self):
         self.stop_node(0)
+        assert os.path.isdir(os.path.join(self.nodes[0].datadir, "regtest", "blocks"))
+        assert not os.path.isdir(os.path.join(self.nodes[0].datadir, "blocks"))
         shutil.rmtree(self.nodes[0].datadir)
         initialize_datadir(self.options.tmpdir, 0)
         self.log.info("Starting with nonexistent blocksdir ...")
diff --git a/test/functional/feature_pruning.py b/test/functional/feature_pruning.py
index 9a3f4fae45..3e1ba88f0a 100755
--- a/test/functional/feature_pruning.py
+++ b/test/functional/feature_pruning.py
@@ -320,7 +320,7 @@ class PruneTest(BitcoinTestFramework):
         if has_block(3):
             raise AssertionError("blk00003.dat is still there, should be pruned by now")
 
-        # stop node, start back up with auto-prune at 550MB, make sure still runs
+        # stop node, start back up with auto-prune at 550 MiB, make sure still runs
         self.stop_node(node_number)
         self.start_node(node_number, extra_args=["-prune=550"])
 
diff --git a/test/functional/feature_segwit.py b/test/functional/feature_segwit.py
index 4bcdf9af55..1efc50e71f 100755
--- a/test/functional/feature_segwit.py
+++ b/test/functional/feature_segwit.py
@@ -43,22 +43,26 @@ class SegWitTest(BitcoinTestFramework):
         self.setup_clean_chain = True
         self.num_nodes = 3
         # This test tests SegWit both pre and post-activation, so use the normal BIP9 activation.
+        # TODO: remove -txindex. Currently required for getrawtransaction call.
         self.extra_args = [
             [
                 "-rpcserialversion=0",
                 "-vbparams=segwit:0:999999999999",
                 "-addresstype=legacy",
+                "-txindex"
             ],
             [
                 "-blockversion=4",
                 "-rpcserialversion=1",
                 "-vbparams=segwit:0:999999999999",
                 "-addresstype=legacy",
+                "-txindex"
             ],
             [
                 "-blockversion=536870915",
                 "-vbparams=segwit:0:999999999999",
                 "-addresstype=legacy",
+                "-txindex"
             ],
         ]
 
diff --git a/test/functional/feature_shutdown.py b/test/functional/feature_shutdown.py
index b633fabb1f..5084cb1322 100755
--- a/test/functional/feature_shutdown.py
+++ b/test/functional/feature_shutdown.py
@@ -5,7 +5,7 @@
 """Test bitcoind shutdown."""
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import assert_equal, get_rpc_proxy
+from test_framework.util import assert_equal, get_rpc_proxy, wait_until
 from threading import Thread
 
 def test_long_call(node):
@@ -20,8 +20,14 @@ class ShutdownTest(BitcoinTestFramework):
 
     def run_test(self):
         node = get_rpc_proxy(self.nodes[0].url, 1, timeout=600, coveragedir=self.nodes[0].coverage_dir)
+        # Force connection establishment by executing a dummy command.
+        node.getblockcount()
         Thread(target=test_long_call, args=(node,)).start()
-        # wait 1 second to ensure event loop waits for current connections to close
+        # Wait until the server is executing the above `waitfornewblock`.
+        wait_until(lambda: len(self.nodes[0].getrpcinfo()['active_commands']) == 2)
+        # Wait 1 second after requesting shutdown but not before the `stop` call
+        # finishes. This is to ensure event loop waits for current connections
+        # to close.
         self.stop_node(0, wait=1000)
 
 if __name__ == '__main__':
diff --git a/test/functional/interface_rest.py b/test/functional/interface_rest.py
index afa9de580f..f850a54462 100755
--- a/test/functional/interface_rest.py
+++ b/test/functional/interface_rest.py
@@ -41,7 +41,8 @@ class RESTTest (BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 2
-        self.extra_args = [["-rest"], []]
+        # TODO: remove -txindex. Currently required for getrawtransaction call.
+        self.extra_args = [["-rest", "-txindex"], []]
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()
@@ -198,9 +199,19 @@ class RESTTest (BitcoinTestFramework):
         self.nodes[0].generate(1)  # generate block to not affect upcoming tests
         self.sync_all()
 
-        self.log.info("Test the /block and /headers URIs")
+        self.log.info("Test the /block, /blockhashbyheight and /headers URIs")
         bb_hash = self.nodes[0].getbestblockhash()
 
+        # Check result if block does not exists
+        assert_equal(self.test_rest_request('/headers/1/0000000000000000000000000000000000000000000000000000000000000000'), [])
+        self.test_rest_request('/block/0000000000000000000000000000000000000000000000000000000000000000', status=404, ret_type=RetType.OBJ)
+
+        # Check result if block is not in the active chain
+        self.nodes[0].invalidateblock(bb_hash)
+        assert_equal(self.test_rest_request('/headers/1/{}'.format(bb_hash)), [])
+        self.test_rest_request('/block/{}'.format(bb_hash))
+        self.nodes[0].reconsiderblock(bb_hash)
+
         # Check binary format
         response = self.test_rest_request("/block/{}".format(bb_hash), req_type=ReqType.BIN, ret_type=RetType.OBJ)
         assert_greater_than(int(response.getheader('content-length')), 80)
@@ -227,6 +238,23 @@ class RESTTest (BitcoinTestFramework):
         # Check json format
         block_json_obj = self.test_rest_request("/block/{}".format(bb_hash))
         assert_equal(block_json_obj['hash'], bb_hash)
+        assert_equal(self.test_rest_request("/blockhashbyheight/{}".format(block_json_obj['height']))['blockhash'], bb_hash)
+
+        # Check hex/bin format
+        resp_hex = self.test_rest_request("/blockhashbyheight/{}".format(block_json_obj['height']), req_type=ReqType.HEX, ret_type=RetType.OBJ)
+        assert_equal(resp_hex.read().decode('utf-8').rstrip(), bb_hash)
+        resp_bytes = self.test_rest_request("/blockhashbyheight/{}".format(block_json_obj['height']), req_type=ReqType.BIN, ret_type=RetType.BYTES)
+        blockhash = binascii.hexlify(resp_bytes[::-1]).decode('utf-8')
+        assert_equal(blockhash, bb_hash)
+
+        # Check invalid blockhashbyheight requests
+        resp = self.test_rest_request("/blockhashbyheight/abc", ret_type=RetType.OBJ, status=400)
+        assert_equal(resp.read().decode('utf-8').rstrip(), "Invalid height: abc")
+        resp = self.test_rest_request("/blockhashbyheight/1000000", ret_type=RetType.OBJ, status=404)
+        assert_equal(resp.read().decode('utf-8').rstrip(), "Block height out of range")
+        resp = self.test_rest_request("/blockhashbyheight/-1", ret_type=RetType.OBJ, status=400)
+        assert_equal(resp.read().decode('utf-8').rstrip(), "Invalid height: -1")
+        self.test_rest_request("/blockhashbyheight/", ret_type=RetType.OBJ, status=400)
 
         # Compare with json block header
         json_obj = self.test_rest_request("/headers/1/{}".format(bb_hash))
diff --git a/test/functional/p2p_invalid_messages.py b/test/functional/p2p_invalid_messages.py
index dbc5c5fff6..dcc0d1d235 100755
--- a/test/functional/p2p_invalid_messages.py
+++ b/test/functional/p2p_invalid_messages.py
@@ -16,7 +16,7 @@ class msg_unrecognized:
 
     command = b'badmsg'
 
-    def __init__(self, str_data):
+    def __init__(self, *, str_data):
         self.str_data = str_data.encode() if not isinstance(str_data, bytes) else str_data
 
     def serialize(self):
@@ -26,19 +26,14 @@ class msg_unrecognized:
         return "{}(data={})".format(self.command, self.str_data)
 
 
-class msg_nametoolong(msg_unrecognized):
-
-    command = b'thisnameiswayyyyyyyyytoolong'
-
-
 class InvalidMessagesTest(BitcoinTestFramework):
-
     def set_test_params(self):
         self.num_nodes = 1
         self.setup_clean_chain = True
 
     def run_test(self):
         """
+         . Test msg header
         0. Send a bunch of large (4MB) messages of an unrecognized type. Check to see
            that it isn't an effective DoS against the node.
 
@@ -46,10 +41,12 @@ class InvalidMessagesTest(BitcoinTestFramework):
 
         2. Send a few messages with an incorrect data size in the header, ensure the
            messages are ignored.
-
-        3. Send an unrecognized message with a command name longer than 12 characters.
-
         """
+        self.test_magic_bytes()
+        self.test_checksum()
+        self.test_size()
+        self.test_command()
+
         node = self.nodes[0]
         self.node = node
         node.add_p2p_connection(P2PDataStore())
@@ -64,7 +61,7 @@ class InvalidMessagesTest(BitcoinTestFramework):
         # Send as large a message as is valid, ensure we aren't disconnected but
         # also can't exhaust resources.
         #
-        msg_at_size = msg_unrecognized("b" * valid_data_limit)
+        msg_at_size = msg_unrecognized(str_data="b" * valid_data_limit)
         assert len(msg_at_size.serialize()) == msg_limit
 
         increase_allowed = 0.5
@@ -94,10 +91,10 @@ class InvalidMessagesTest(BitcoinTestFramework):
         #
         # Send an oversized message, ensure we're disconnected.
         #
-        msg_over_size = msg_unrecognized("b" * (valid_data_limit + 1))
+        msg_over_size = msg_unrecognized(str_data="b" * (valid_data_limit + 1))
         assert len(msg_over_size.serialize()) == (msg_limit + 1)
 
-        with node.assert_debug_log(["Oversized message from peer=0, disconnecting"]):
+        with node.assert_debug_log(["Oversized message from peer=4, disconnecting"]):
             # An unknown message type (or *any* message type) over
             # MAX_PROTOCOL_MESSAGE_LENGTH should result in a disconnect.
             node.p2p.send_message(msg_over_size)
@@ -113,7 +110,7 @@ class InvalidMessagesTest(BitcoinTestFramework):
         # Send messages with an incorrect data size in the header.
         #
         actual_size = 100
-        msg = msg_unrecognized("b" * actual_size)
+        msg = msg_unrecognized(str_data="b" * actual_size)
 
         # TODO: handle larger-than cases. I haven't been able to pin down what behavior to expect.
         for wrong_size in (2, 77, 78, 79):
@@ -140,18 +137,58 @@ class InvalidMessagesTest(BitcoinTestFramework):
             node.disconnect_p2ps()
             node.add_p2p_connection(P2PDataStore())
 
-        #
-        # 3.
-        #
-        # Send a message with a too-long command name.
-        #
-        node.p2p.send_message(msg_nametoolong("foobar"))
-        node.p2p.wait_for_disconnect(timeout=4)
-
         # Node is still up.
         conn = node.add_p2p_connection(P2PDataStore())
         conn.sync_with_ping()
 
+    def test_magic_bytes(self):
+        conn = self.nodes[0].add_p2p_connection(P2PDataStore())
+        conn.magic_bytes = b'\x00\x11\x22\x32'
+        with self.nodes[0].assert_debug_log(['PROCESSMESSAGE: INVALID MESSAGESTART ping']):
+            conn.send_message(messages.msg_ping(nonce=0xff))
+            conn.wait_for_disconnect(timeout=1)
+            self.nodes[0].disconnect_p2ps()
+
+    def test_checksum(self):
+        conn = self.nodes[0].add_p2p_connection(P2PDataStore())
+        with self.nodes[0].assert_debug_log(['ProcessMessages(badmsg, 2 bytes): CHECKSUM ERROR expected 78df0a04 was ffffffff']):
+            msg = conn.build_message(msg_unrecognized(str_data="d"))
+            cut_len = (
+                4 +  # magic
+                12 +  # command
+                4  #len
+            )
+            # modify checksum
+            msg = msg[:cut_len] + b'\xff' * 4 + msg[cut_len + 4:]
+            self.nodes[0].p2p.send_raw_message(msg)
+            conn.sync_with_ping(timeout=1)
+            self.nodes[0].disconnect_p2ps()
+
+    def test_size(self):
+        conn = self.nodes[0].add_p2p_connection(P2PDataStore())
+        with self.nodes[0].assert_debug_log(['']):
+            msg = conn.build_message(msg_unrecognized(str_data="d"))
+            cut_len = (
+                4 +  # magic
+                12  # command
+            )
+            # modify len to MAX_SIZE + 1
+            msg = msg[:cut_len] + struct.pack("<I", 0x02000000 + 1) + msg[cut_len + 4:]
+            self.nodes[0].p2p.send_raw_message(msg)
+            conn.wait_for_disconnect(timeout=1)
+            self.nodes[0].disconnect_p2ps()
+
+    def test_command(self):
+        conn = self.nodes[0].add_p2p_connection(P2PDataStore())
+        with self.nodes[0].assert_debug_log(['PROCESSMESSAGE: ERRORS IN HEADER']):
+            msg = msg_unrecognized(str_data="d")
+            msg.command = b'\xff' * 12
+            msg = conn.build_message(msg)
+            # Modify command
+            msg = msg[:7] + b'\x00' + msg[7 + 1:]
+            self.nodes[0].p2p.send_raw_message(msg)
+            conn.sync_with_ping(timeout=1)
+            self.nodes[0].disconnect_p2ps()
 
     def _tweak_msg_data_size(self, message, wrong_size):
         """
diff --git a/test/functional/p2p_segwit.py b/test/functional/p2p_segwit.py
index d95da227e5..8f8e89cf15 100755
--- a/test/functional/p2p_segwit.py
+++ b/test/functional/p2p_segwit.py
@@ -755,7 +755,7 @@ class SegWitTest(BitcoinTestFramework):
         spend_tx.vin[0].scriptSig = CScript([p2wsh_pubkey, b'a'])
         spend_tx.rehash()
         with self.nodes[0].assert_debug_log(
-                expected_msgs=('Not relaying invalid transaction {}'.format(spend_tx.hash), 'was not accepted: mandatory-script-verify-flag-failed (Script evaluated without error but finished with a false/empty top stack element)')):
+                expected_msgs=(spend_tx.hash, 'was not accepted: mandatory-script-verify-flag-failed (Script evaluated without error but finished with a false/empty top stack element)')):
             test_transaction_acceptance(self.nodes[0], self.test_node, spend_tx, with_witness=False, accepted=False)
 
         # Now put the witness script in the witness, should succeed after
diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index 272ebe65cb..1e10280e60 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -19,6 +19,8 @@ class PSBTTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = False
         self.num_nodes = 3
+       # TODO: remove -txindex. Currently required for getrawtransaction call.
+        self.extra_args = [[], ["-txindex"], ["-txindex"]]
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()
diff --git a/test/functional/rpc_rawtransaction.py b/test/functional/rpc_rawtransaction.py
index 5b9dbef68d..a97d753626 100755
--- a/test/functional/rpc_rawtransaction.py
+++ b/test/functional/rpc_rawtransaction.py
@@ -42,7 +42,8 @@ class RawTransactionsTest(BitcoinTestFramework):
     def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 3
-        self.extra_args = [["-addresstype=legacy"], ["-addresstype=legacy"], ["-addresstype=legacy"]]
+        # TODO: remove -txindex. Currently required for getrawtransaction call.
+        self.extra_args = [["-addresstype=legacy", "-txindex"], ["-addresstype=legacy", "-txindex"], ["-addresstype=legacy", "-txindex"]]
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index ca5734d67d..ac7cc068bd 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -118,7 +118,7 @@ class P2PConnection(asyncio.Protocol):
         # The initial message to send after the connection was made:
         self.on_connection_send_msg = None
         self.recvbuf = b""
-        self.network = net
+        self.magic_bytes = MAGIC_BYTES[net]
         logger.debug('Connecting to Bitcoin Node: %s:%d' % (self.dstaddr, self.dstport))
 
         loop = NetworkThread.network_event_loop
@@ -170,7 +170,7 @@ class P2PConnection(asyncio.Protocol):
             while True:
                 if len(self.recvbuf) < 4:
                     return
-                if self.recvbuf[:4] != MAGIC_BYTES[self.network]:
+                if self.recvbuf[:4] != self.magic_bytes:
                     raise ValueError("got garbage %s" % repr(self.recvbuf))
                 if len(self.recvbuf) < 4 + 12 + 4 + 4:
                     return
@@ -232,7 +232,7 @@ class P2PConnection(asyncio.Protocol):
         """Build a serialized P2P message"""
         command = message.command
         data = message.serialize()
-        tmsg = MAGIC_BYTES[self.network]
+        tmsg = self.magic_bytes
         tmsg += command
         tmsg += b"\x00" * (12 - len(command))
         tmsg += struct.pack("<I", len(data))
diff --git a/test/functional/wallet_abandonconflict.py b/test/functional/wallet_abandonconflict.py
index e5ac2c8bd4..2b684349ce 100755
--- a/test/functional/wallet_abandonconflict.py
+++ b/test/functional/wallet_abandonconflict.py
@@ -18,7 +18,8 @@ from test_framework.util import assert_equal, assert_raises_rpc_error, connect_n
 class AbandonConflictTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
-        self.extra_args = [["-minrelaytxfee=0.00001"], []]
+        # TODO: remove -txindex. Currently required for getrawtransaction call.
+        self.extra_args = [["-minrelaytxfee=0.00001", "-txindex"], []]
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()
diff --git a/test/functional/wallet_basic.py b/test/functional/wallet_basic.py
index 7184bb8cb6..daae2ed3c0 100755
--- a/test/functional/wallet_basic.py
+++ b/test/functional/wallet_basic.py
@@ -23,6 +23,8 @@ class WalletTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 4
         self.setup_clean_chain = True
+        # TODO: remove -txindex. Currently required for getrawtransaction call.
+        self.extra_args = [[], [], ["-txindex"], []]
 
     def skip_test_if_missing_module(self):
         self.skip_if_no_wallet()
diff --git a/test/lint/check-doc.py b/test/lint/check-doc.py
index 4facd6c334..c370ce0c04 100755
--- a/test/lint/check-doc.py
+++ b/test/lint/check-doc.py
@@ -30,8 +30,8 @@ def main():
         used = check_output(CMD_GREP_ARGS, shell=True, universal_newlines=True, encoding='utf8')
         docd = check_output(CMD_GREP_DOCS, shell=True, universal_newlines=True, encoding='utf8')
     else:
-        used = check_output(CMD_GREP_ARGS, shell=True, universal_newlines=True) # encoding='utf8'
-        docd = check_output(CMD_GREP_DOCS, shell=True, universal_newlines=True) # encoding='utf8'
+        used = check_output(CMD_GREP_ARGS, shell=True).decode('utf8').strip()
+        docd = check_output(CMD_GREP_DOCS, shell=True).decode('utf8').strip()
 
     args_used = set(re.findall(re.compile(REGEX_ARG), used))
     args_docd = set(re.findall(re.compile(REGEX_DOC), docd)).union(SET_DOC_OPTIONAL)
diff --git a/test/lint/lint-format-strings.sh b/test/lint/lint-format-strings.sh
index 2c443abf6b..c994ae3f4d 100755
--- a/test/lint/lint-format-strings.sh
+++ b/test/lint/lint-format-strings.sh
@@ -11,20 +11,20 @@
 export LC_ALL=C
 
 FUNCTION_NAMES_AND_NUMBER_OF_LEADING_ARGUMENTS=(
-    FatalError,0
-    fprintf,1
-    LogConnectFailure,1
-    LogPrint,1
-    LogPrintf,0
-    printf,0
-    snprintf,2
-    sprintf,1
-    strprintf,0
-    vfprintf,1
-    vprintf,1
-    vsnprintf,1
-    vsprintf,1
-    WalletLogPrintf,0
+    "FatalError,0"
+    "fprintf,1"
+    "LogConnectFailure,1"
+    "LogPrint,1"
+    "LogPrintf,0"
+    "printf,0"
+    "snprintf,2"
+    "sprintf,1"
+    "strprintf,0"
+    "vfprintf,1"
+    "vprintf,1"
+    "vsnprintf,1"
+    "vsprintf,1"
+    "WalletLogPrintf,0"
 )
 
 EXIT_CODE=0
diff --git a/test/lint/lint-python.sh b/test/lint/lint-python.sh
index 3dbb9fff28..f5b851aeab 100755
--- a/test/lint/lint-python.sh
+++ b/test/lint/lint-python.sh
@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 #
 # Copyright (c) 2017 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
@@ -8,77 +8,79 @@
 
 export LC_ALL=C
 
-# E101 indentation contains mixed spaces and tabs
-# E112 expected an indented block
-# E113 unexpected indentation
-# E115 expected an indented block (comment)
-# E116 unexpected indentation (comment)
-# E125 continuation line with same indent as next logical line
-# E129 visually indented line with same indent as next logical line
-# E131 continuation line unaligned for hanging indent
-# E133 closing bracket is missing indentation
-# E223 tab before operator
-# E224 tab after operator
-# E242 tab after ','
-# E266 too many leading '#' for block comment
-# E271 multiple spaces after keyword
-# E272 multiple spaces before keyword
-# E273 tab after keyword
-# E274 tab before keyword
-# E275 missing whitespace after keyword
-# E304 blank lines found after function decorator
-# E306 expected 1 blank line before a nested definition
-# E401 multiple imports on one line
-# E402 module level import not at top of file
-# F403 'from foo_module import *' used; unable to detect undefined names
-# F405 foo_function may be undefined, or defined from star imports: bar_module
-# E502 the backslash is redundant between brackets
-# E701 multiple statements on one line (colon)
-# E702 multiple statements on one line (semicolon)
-# E703 statement ends with a semicolon
-# E711 comparison to None should be 'if cond is None:'
-# E714 test for object identity should be "is not"
-# E721 do not compare types, use "isinstance()"
-# E741 do not use variables named "l", "O", or "I"
-# E742 do not define classes named "l", "O", or "I"
-# E743 do not define functions named "l", "O", or "I"
-# E901 SyntaxError: invalid syntax
-# E902 TokenError: EOF in multi-line string
-# F401 module imported but unused
-# F402 import module from line N shadowed by loop variable
-# F404 future import(s) name after other statements
-# F406 "from module import *" only allowed at module level
-# F407 an undefined __future__ feature name was imported
-# F601 dictionary key name repeated with different values
-# F602 dictionary key variable name repeated with different values
-# F621 too many expressions in an assignment with star-unpacking
-# F622 two or more starred expressions in an assignment (a, *b, *c = d)
-# F631 assertion test is a tuple, which are always True
-# F701 a break statement outside of a while or for loop
-# F702 a continue statement outside of a while or for loop
-# F703 a continue statement in a finally block in a loop
-# F704 a yield or yield from statement outside of a function
-# F705 a return statement with arguments inside a generator
-# F706 a return statement outside of a function/method
-# F707 an except: block as not the last exception handler
-# F811 redefinition of unused name from line N
-# F812 list comprehension redefines 'foo' from line N
-# F821 undefined name 'Foo'
-# F822 undefined name name in __all__
-# F823 local variable name … referenced before assignment
-# F831 duplicate argument name in function definition
-# F841 local variable 'foo' is assigned to but never used
-# W191 indentation contains tabs
-# W291 trailing whitespace
-# W292 no newline at end of file
-# W293 blank line contains whitespace
-# W504 line break after binary operator
-# W601 .has_key() is deprecated, use "in"
-# W602 deprecated form of raising exception
-# W603 "<>" is deprecated, use "!="
-# W604 backticks are deprecated, use "repr()"
-# W605 invalid escape sequence "x"
-# W606 'async' and 'await' are reserved keywords starting with Python 3.7
+enabled=(
+    E101 # indentation contains mixed spaces and tabs
+    E112 # expected an indented block
+    E113 # unexpected indentation
+    E115 # expected an indented block (comment)
+    E116 # unexpected indentation (comment)
+    E125 # continuation line with same indent as next logical line
+    E129 # visually indented line with same indent as next logical line
+    E131 # continuation line unaligned for hanging indent
+    E133 # closing bracket is missing indentation
+    E223 # tab before operator
+    E224 # tab after operator
+    E242 # tab after ','
+    E266 # too many leading '#' for block comment
+    E271 # multiple spaces after keyword
+    E272 # multiple spaces before keyword
+    E273 # tab after keyword
+    E274 # tab before keyword
+    E275 # missing whitespace after keyword
+    E304 # blank lines found after function decorator
+    E306 # expected 1 blank line before a nested definition
+    E401 # multiple imports on one line
+    E402 # module level import not at top of file
+    E502 # the backslash is redundant between brackets
+    E701 # multiple statements on one line (colon)
+    E702 # multiple statements on one line (semicolon)
+    E703 # statement ends with a semicolon
+    E711 # comparison to None should be 'if cond is None:'
+    E714 # test for object identity should be "is not"
+    E721 # do not compare types, use "isinstance()"
+    E741 # do not use variables named "l", "O", or "I"
+    E742 # do not define classes named "l", "O", or "I"
+    E743 # do not define functions named "l", "O", or "I"
+    E901 # SyntaxError: invalid syntax
+    E902 # TokenError: EOF in multi-line string
+    F401 # module imported but unused
+    F402 # import module from line N shadowed by loop variable
+    F403 # 'from foo_module import *' used; unable to detect undefined names
+    F404 # future import(s) name after other statements
+    F405 # foo_function may be undefined, or defined from star imports: bar_module
+    F406 # "from module import *" only allowed at module level
+    F407 # an undefined __future__ feature name was imported
+    F601 # dictionary key name repeated with different values
+    F602 # dictionary key variable name repeated with different values
+    F621 # too many expressions in an assignment with star-unpacking
+    F622 # two or more starred expressions in an assignment (a, *b, *c = d)
+    F631 # assertion test is a tuple, which are always True
+    F701 # a break statement outside of a while or for loop
+    F702 # a continue statement outside of a while or for loop
+    F703 # a continue statement in a finally block in a loop
+    F704 # a yield or yield from statement outside of a function
+    F705 # a return statement with arguments inside a generator
+    F706 # a return statement outside of a function/method
+    F707 # an except: block as not the last exception handler
+    F811 # redefinition of unused name from line N
+    F812 # list comprehension redefines 'foo' from line N
+    F821 # undefined name 'Foo'
+    F822 # undefined name name in __all__
+    F823 # local variable name … referenced before assignment
+    F831 # duplicate argument name in function definition
+    F841 # local variable 'foo' is assigned to but never used
+    W191 # indentation contains tabs
+    W291 # trailing whitespace
+    W292 # no newline at end of file
+    W293 # blank line contains whitespace
+    W504 # line break after binary operator
+    W601 # .has_key() is deprecated, use "in"
+    W602 # deprecated form of raising exception
+    W603 # "<>" is deprecated, use "!="
+    W604 # backticks are deprecated, use "repr()"
+    W605 # invalid escape sequence "x"
+    W606 # 'async' and 'await' are reserved keywords starting with Python 3.7
+)
 
 if ! command -v flake8 > /dev/null; then
     echo "Skipping Python linting since flake8 is not installed. Install by running \"pip3 install flake8\""
@@ -88,4 +90,4 @@ elif PYTHONWARNINGS="ignore" flake8 --version | grep -q "Python 2"; then
     exit 0
 fi
 
-PYTHONWARNINGS="ignore" flake8 --ignore=B,C,E,F,I,N,W --select=E101,E112,E113,E115,E116,E125,E129,E131,E133,E223,E224,E242,E266,E271,E272,E273,E274,E275,E304,E306,E401,E402,E502,E701,E702,E703,E711,E714,E721,E741,E742,E743,E901,E902,F401,F402,F403,F404,F405,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F821,F822,F823,F831,F841,W191,W291,W292,W293,W504,W601,W602,W603,W604,W605,W606 "${@:-.}"
+PYTHONWARNINGS="ignore" flake8 --ignore=B,C,E,F,I,N,W --select=$(IFS=","; echo "${enabled[*]}") "${@:-.}"
diff --git a/test/lint/lint-shell.sh b/test/lint/lint-shell.sh
index 7ed239576e..6f5e6546c5 100755
--- a/test/lint/lint-shell.sh
+++ b/test/lint/lint-shell.sh
@@ -13,7 +13,7 @@ export LC_ALL=C
 # respectively. So export LC_ALL=C is set as required by lint-shell-locale.sh
 # but unset here in case of running in Travis.
 if [ "$TRAVIS" = "true" ]; then
-  unset LC_ALL
+    unset LC_ALL
 fi
 
 if ! command -v shellcheck > /dev/null; then
@@ -22,27 +22,26 @@ if ! command -v shellcheck > /dev/null; then
 fi
 
 # Disabled warnings:
-# SC1087: Use braces when expanding arrays, e.g. ${array[idx]} (or ${var}[.. to quiet).
-# SC1117: Backslash is literal in "\.". Prefer explicit escaping: "\\.".
-# SC2001: See if you can use ${variable//search/replace} instead.
-# SC2004: $/${} is unnecessary on arithmetic variables.
-# SC2005: Useless echo? Instead of 'echo $(cmd)', just use 'cmd'.
-# SC2006: Use $(..) instead of legacy `..`.
-# SC2016: Expressions don't expand in single quotes, use double quotes for that.
-# SC2028: echo won't expand escape sequences. Consider printf.
-# SC2046: Quote this to prevent word splitting.
-# SC2048: Use "$@" (with quotes) to prevent whitespace problems.
-# SC2066: Since you double quoted this, it will not word split, and the loop will only run once.
-# SC2086: Double quote to prevent globbing and word splitting.
-# SC2116: Useless echo? Instead of 'cmd $(echo foo)', just use 'cmd foo'.
-# SC2148: Tips depend on target shell and yours is unknown. Add a shebang.
-# SC2162: read without -r will mangle backslashes.
-# SC2166: Prefer [ p ] && [ q ] as [ p -a q ] is not well defined.
-# SC2166: Prefer [ p ] || [ q ] as [ p -o q ] is not well defined.
-# SC2181: Check exit code directly with e.g. 'if mycmd;', not indirectly with $?.
-# SC2206: Quote to prevent word splitting, or split robustly with mapfile or read -a.
-# SC2207: Prefer mapfile or read -a to split command output (or quote to avoid splitting).
-# SC2230: which is non-standard. Use builtin 'command -v' instead.
-# SC2236: Don't force -n instead of ! -z.
-shellcheck -e SC1087,SC1117,SC2001,SC2004,SC2005,SC2006,SC2016,SC2028,SC2046,SC2048,SC2066,SC2086,SC2116,SC2148,SC2162,SC2166,SC2181,SC2206,SC2207,SC2230,SC2236 \
+disabled=(
+    SC1087 # Use braces when expanding arrays, e.g. ${array[idx]} (or ${var}[.. to quiet).
+    SC2001 # See if you can use ${variable//search/replace} instead.
+    SC2004 # $/${} is unnecessary on arithmetic variables.
+    SC2005 # Useless echo? Instead of 'echo $(cmd)', just use 'cmd'.
+    SC2006 # Use $(..) instead of legacy `..`.
+    SC2016 # Expressions don't expand in single quotes, use double quotes for that.
+    SC2028 # echo won't expand escape sequences. Consider printf.
+    SC2046 # Quote this to prevent word splitting.
+    SC2048 # Use "$@" (with quotes) to prevent whitespace problems.
+    SC2066 # Since you double quoted this, it will not word split, and the loop will only run once.
+    SC2086 # Double quote to prevent globbing and word splitting.
+    SC2116 # Useless echo? Instead of 'cmd $(echo foo)', just use 'cmd foo'.
+    SC2162 # read without -r will mangle backslashes.
+    SC2166 # Prefer [ p ] {&&,||} [ q ] as [ p -{a,o} q ] is not well defined.
+    SC2181 # Check exit code directly with e.g. 'if mycmd;', not indirectly with $?.
+    SC2206 # Quote to prevent word splitting, or split robustly with mapfile or read -a.
+    SC2207 # Prefer mapfile or read -a to split command output (or quote to avoid splitting).
+    SC2230 # which is non-standard. Use builtin 'command -v' instead.
+    SC2236 # Don't force -n instead of ! -z.
+)
+shellcheck -e "$(IFS=","; echo "${disabled[*]}")" \
     $(git ls-files -- "*.sh" | grep -vE 'src/(secp256k1|univalue)/')
diff --git a/test/lint/lint-whitespace.sh b/test/lint/lint-whitespace.sh
index beb7ec42f4..f318e19071 100755
--- a/test/lint/lint-whitespace.sh
+++ b/test/lint/lint-whitespace.sh
@@ -23,7 +23,7 @@ while getopts "?" opt; do
 done
 
 if [ -z "${TRAVIS_COMMIT_RANGE}" ]; then
-  if [ "$1" ]; then
+  if [ -n "$1" ]; then
     TRAVIS_COMMIT_RANGE="HEAD~$1...HEAD"
   else
     TRAVIS_COMMIT_RANGE="HEAD"