MDEV-9840: Test encryption.innodb-log-encrypt-crash fails on buildbot

Problem: We created more than 5 encryption keys for redo-logs.
Idea was that we do not anymore create more than one encryption
key for redo-logs but if existing checkpoint from earlier
MariaDB contains more keys, we should read all of them.

Fix: Add new encryption key to memory structure only if there
currently has none or if we are reading checkpoint from the log.
Checkpoint from older MariaDB version could contain more than
one key.

storage/innobase/log/log0crypt.cc

@@ -301,7 +301,10 @@ Add crypt info to set if it is not already present
 @return true if successfull, false if not- */
 static
 bool
-add_crypt_info(crypt_info_t* info)
+add_crypt_info(
+/*===========*/
+	crypt_info_t*	info,		/*!< in: crypt info */
+	bool		checkpoint_read)/*!< in: do we read checkpoint */
 {
 	const crypt_info_t* found=NULL;
 	/* so that no one is searching array while we modify it */
@@ -309,7 +312,11 @@ add_crypt_info(crypt_info_t* info)
 
 	found = get_crypt_info(info->checkpoint_no);
 
-	if (found != NULL && found->checkpoint_no == info->checkpoint_no) {
+	/* If one crypt info is found then we add a new one only if we
+	are reading checkpoint from the log. New checkpoints will always
+	use the first created crypt info. */
+	if (found != NULL &&
+		( found->checkpoint_no == info->checkpoint_no || !checkpoint_read)) {
 		// already present...
 		return true;
 	}
@@ -382,7 +389,7 @@ log_crypt_set_ver_and_key(
 
 	}
 
-	add_crypt_info(&info);
+	add_crypt_info(&info, false);
 }
 
 /********************************************************
@@ -540,7 +547,7 @@ log_crypt_read_checkpoint_buf(
 		memcpy(info.crypt_msg, buf + 8, MY_AES_BLOCK_SIZE);
 		memcpy(info.crypt_nonce, buf + 24, MY_AES_BLOCK_SIZE);
 
-		if (!add_crypt_info(&info)) {
+		if (!add_crypt_info(&info, true)) {
 			return false;
 		}
 		buf += LOG_CRYPT_ENTRY_SIZE;

storage/xtradb/log/log0crypt.cc

@@ -301,7 +301,10 @@ Add crypt info to set if it is not already present
 @return true if successfull, false if not- */
 static
 bool
-add_crypt_info(crypt_info_t* info)
+add_crypt_info(
+/*===========*/
+	crypt_info_t*	info,		/*!< in: crypt info */
+	bool		checkpoint_read)/*!< in: do we read checkpoint */
 {
 	const crypt_info_t* found=NULL;
 	/* so that no one is searching array while we modify it */
@@ -309,7 +312,11 @@ add_crypt_info(crypt_info_t* info)
 
 	found = get_crypt_info(info->checkpoint_no);
 
-	if (found != NULL && found->checkpoint_no == info->checkpoint_no) {
+	/* If one crypt info is found then we add a new one only if we
+	are reading checkpoint from the log. New checkpoints will always
+	use the first created crypt info. */
+	if (found != NULL &&
+		( found->checkpoint_no == info->checkpoint_no || !checkpoint_read)) {
 		// already present...
 		return true;
 	}
@@ -382,7 +389,7 @@ log_crypt_set_ver_and_key(
 
 	}
 
-	add_crypt_info(&info);
+	add_crypt_info(&info, false);
 }
 
 /********************************************************
@@ -540,7 +547,7 @@ log_crypt_read_checkpoint_buf(
 		memcpy(info.crypt_msg, buf + 8, MY_AES_BLOCK_SIZE);
 		memcpy(info.crypt_nonce, buf + 24, MY_AES_BLOCK_SIZE);
 
-		if (!add_crypt_info(&info)) {
+		if (!add_crypt_info(&info, true)) {
 			return false;
 		}
 		buf += LOG_CRYPT_ENTRY_SIZE;