support encrypted/compressed objects properly during decommission (#15320)

fixes #15314

docs/distributed/decom.sh

@@ -1,16 +1,19 @@
 #!/bin/bash
 
-if [ -n "$DEBUG" ]; then
+if [ -n "$TEST_DEBUG" ]; then
     set -x
 fi
 
 pkill minio
 rm -rf /tmp/xl
 
-wget --quiet -O mc https://dl.minio.io/client/mc/release/linux-amd64/mc && \
-    chmod +x mc
+if [ ! -f ./mc ]; then
+    wget --quiet -O mc https://dl.minio.io/client/mc/release/linux-amd64/mc && \
+	chmod +x mc
+fi
 
 export CI=true
+
 (minio server /tmp/xl/{1...10}/disk{0...1} 2>&1 >/dev/null)&
 pid=$!
 
@@ -37,6 +40,8 @@ export MC_HOST_myminio="http://minioadmin:minioadmin@localhost:9000/"
 ## mirror again to create another set of version on top
 ./mc mirror internal myminio/versioned/ --quiet >/dev/null
 
+expected_checksum=$(./mc cat internal/dsync/drwmutex.go | md5sum)
+
 user_count=$(./mc admin user list myminio/ | wc -l)
 policy_count=$(./mc admin policy list myminio/ | wc -l)
 
@@ -113,12 +118,20 @@ out=$(diff -qpruN expanded_ns.txt decommissioned_ns.txt)
 ret=$?
 if [ $ret -ne 0 ]; then
     echo "BUG: expected no missing entries after decommission: $out"
+    exit 1
 fi
 
 out=$(diff -qpruN expanded_ns_versions.txt decommissioned_ns_versions.txt)
 ret=$?
 if [ $ret -ne 0 ]; then
     echo "BUG: expected no missing entries after decommission: $out"
+    exit 1
+fi
+
+got_checksum=$(./mc cat myminio/versioned/dsync/drwmutex.go | md5sum)
+if [ "${expected_checksum}" != "${got_checksum}" ]; then
+    echo "BUG: decommission failed on encrypted objects: expected ${expected_checksum} got ${got_checksum}"
+    exit 1
 fi
 
 kill $pid