3 files changed, 18 insertions, 6 deletions
diff --git a/lib/sqfs/blk_proc/process_block.c b/lib/sqfs/blk_proc/process_block.c
index 0747bc5..5d1fa58 100644
--- a/lib/sqfs/blk_proc/process_block.c
+++ b/lib/sqfs/blk_proc/process_block.c
@@ -15,8 +15,7 @@ int sqfs_block_process(sqfs_block_t *block, sqfs_compressor_t *cmp,
 {
 	ssize_t ret;
 
-	if (!(block->flags & SQFS_BLK_DONT_CHECKSUM))
-		block->checksum = crc32(0, block->data, block->size);
+	block->checksum = crc32(0, block->data, block->size);
 
 	if (!(block->flags & SQFS_BLK_DONT_COMPRESS)) {
 		ret = cmp->do_block(cmp, block->data, block->size,
diff --git a/lib/sqfs/blk_proc/pthread.c b/lib/sqfs/blk_proc/pthread.c
index a9cffd0..f1874c0 100644
--- a/lib/sqfs/blk_proc/pthread.c
+++ b/lib/sqfs/blk_proc/pthread.c
@@ -193,12 +193,15 @@ int sqfs_block_processor_enqueue(sqfs_block_processor_t *proc,
 {
 	sqfs_block_t *queue = NULL, *it, *prev;
 
+	if (block->flags & ~SQFS_BLK_USER_SETTABLE_FLAGS)
+		return SQFS_ERROR_UNSUPPORTED;
+
 	block->sequence_number = proc->enqueue_id++;
 	block->next = NULL;
 
 	pthread_mutex_lock(&proc->mtx);
-	if ((block->flags & SQFS_BLK_DONT_COMPRESS) &&
-	    (block->flags & SQFS_BLK_DONT_CHECKSUM)) {
+	if (block->size == 0) {
+		block->checksum = 0;
 		store_completed_block(proc, block);
 	} else {
 		while (proc->backlog > proc->max_backlog)
diff --git a/lib/sqfs/blk_proc/serial.c b/lib/sqfs/blk_proc/serial.c
index b6c17fb..b7bc545 100644
--- a/lib/sqfs/blk_proc/serial.c
+++ b/lib/sqfs/blk_proc/serial.c
@@ -51,8 +51,18 @@ int sqfs_block_processor_enqueue(sqfs_block_processor_t *proc,
 		return proc->status;
 	}
 
-	proc->status = sqfs_block_process(block, proc->cmp,
-					  proc->scratch, proc->max_block_size);
+	if (block->flags & ~SQFS_BLK_USER_SETTABLE_FLAGS) {
+		proc->status = SQFS_ERROR_UNSUPPORTED;
+		return proc->status;
+	}
+
+	if (block->size == 0) {
+		block->checksum = 0;
+	} else {
+		proc->status = sqfs_block_process(block, proc->cmp,
+						  proc->scratch,
+						  proc->max_block_size);
+	}
 
 	block->next = NULL;
 	return process_completed_blocks(proc, block);