Merge bitcoin/bitcoin#28628: lint: Include test_utxo_snapshots in lin…

…t_shell, fix linter errors

348e79f lint: Include test_utxo_snapshots in lint_shell (Fabian Jahr)

Pull request description:

  jamesob excluded `test_utxo_snapshots.sh` from the shell linter with this explanation: "Add the script to the shellcheck exception list since the quoted variables rule needs to be violated in order to get bitcoind to pick up on $EARLY_IBD_FLAGS." However, macrofake pointed out that single lines can be excluded from linting.

  This fixes one fixable rule violation, excludes the rest of the offending lines from the linter and then removes the exclusion of the `test_utxo_snapshots.sh` file. Also adds documentation.

ACKs for top commit:
  Empact:
    ACK 348e79f
  maflcko:
    lgtm ACK 348e79f
  pablomartin4btc:
    tACK 348e79f

Tree-SHA512: a904cc1cc3c94488dfbd39ea69a3ef17259f991708a797009001669448fef81eed086ecbce1ec433988d88baef293849698e2e0eb86a969b949cc7ef93af7b4b

contrib/devtools/test_utxo_snapshots.sh

@@ -11,13 +11,16 @@
 # loaded. We see the background validation chainstate removed after validation
 # completes.
 #
+# The shellcheck rule SC2086 (quoted variables) disablements are necessary
+# since this rule needs to be violated in order to get bitcoind to pick up on
+# $EARLY_IBD_FLAGS for the script to work.
 
 export LC_ALL=C
 set -e
 
 BASE_HEIGHT=${1:-30000}
 INCREMENTAL_HEIGHT=20000
-FINAL_HEIGHT=$(($BASE_HEIGHT + $INCREMENTAL_HEIGHT))
+FINAL_HEIGHT=$((BASE_HEIGHT + INCREMENTAL_HEIGHT))
 
 SERVER_DATADIR="$(pwd)/utxodemo-data-server-$BASE_HEIGHT"
 CLIENT_DATADIR="$(pwd)/utxodemo-data-client-$BASE_HEIGHT"
@@ -107,12 +110,14 @@ read -p "Press [enter] to continue" _
 
 echo
 echo "-- IBDing the blocks (height=$BASE_HEIGHT) required to the server node..."
+# shellcheck disable=SC2086
 ./src/bitcoind -logthreadnames=1 $SERVER_PORTS \
     -datadir="$SERVER_DATADIR" $EARLY_IBD_FLAGS -stopatheight="$BASE_HEIGHT" >/dev/null
 
 echo
 echo "-- Creating snapshot at ~ height $BASE_HEIGHT ($UTXO_DAT_FILE)..."
 server_sleep_til_shutdown # wait for stopatheight to be hit
+# shellcheck disable=SC2086
 ./src/bitcoind -logthreadnames=1 $SERVER_PORTS \
     -datadir="$SERVER_DATADIR" $EARLY_IBD_FLAGS -connect=0 -listen=0 >/dev/null &
 SERVER_PID="$!"
@@ -137,11 +142,13 @@ echo "   {${RPC_BASE_HEIGHT}, AssumeutxoHash{uint256S(\"0x${RPC_AU}\")}, ${RPC_N
 echo
 echo
 echo "-- IBDing more blocks to the server node (height=$FINAL_HEIGHT) so there is a diff between snapshot and tip..."
+# shellcheck disable=SC2086
 ./src/bitcoind $SERVER_PORTS -logthreadnames=1 -datadir="$SERVER_DATADIR" \
     $EARLY_IBD_FLAGS -stopatheight="$FINAL_HEIGHT" >/dev/null
 
 echo
 echo "-- Starting the server node to provide blocks to the client node..."
+# shellcheck disable=SC2086
 ./src/bitcoind $SERVER_PORTS -logthreadnames=1 -debug=net -datadir="$SERVER_DATADIR" \
     $EARLY_IBD_FLAGS -connect=0 -listen=1 >/dev/null &
 SERVER_PID="$!"
@@ -165,6 +172,7 @@ read -p "When you're ready for all this, hit [enter]" _
 
 echo
 echo "-- Starting the client node to get headers from the server, then load the snapshot..."
+# shellcheck disable=SC2086
 ./src/bitcoind $CLIENT_PORTS $ALL_INDEXES -logthreadnames=1 -datadir="$CLIENT_DATADIR" \
     -connect=0 -addnode=127.0.0.1:$SERVER_PORT -debug=net $EARLY_IBD_FLAGS >/dev/null &
 CLIENT_PID="$!"
@@ -189,6 +197,7 @@ echo
 read -p "Press [enter] to continue"
 
 client_sleep_til_boot
+# shellcheck disable=SC2086
 ./src/bitcoind $CLIENT_PORTS $ALL_INDEXES -logthreadnames=1 -datadir="$CLIENT_DATADIR" -connect=0 \
     -addnode=127.0.0.1:$SERVER_PORT "$EARLY_IBD_FLAGS" >/dev/null &
 CLIENT_PID="$!"

test/lint/lint-shell.py

@@ -70,7 +70,7 @@ def main():
     reg = re.compile(r'src/[leveldb,secp256k1,minisketch]')
 
     def should_exclude(fname: str) -> bool:
-        return bool(reg.match(fname)) or 'test_utxo_snapshots.sh' in fname
+        return bool(reg.match(fname))
 
     # remove everything that doesn't match this regex
     files[:] = [file for file in files if not should_exclude(file)]