3 files changed, 24 insertions, 4 deletions

diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c
index 578d257a..efe6c226 100644
--- a/src/liblzma/common/common.c
+++ b/src/liblzma/common/common.c
@@ -176,7 +176,7 @@ lzma_code(lzma_stream *strm, lzma_action action)
 			|| (strm->next_out == NULL && strm->avail_out != 0)
 			|| strm->internal == NULL
 			|| strm->internal->next.code == NULL
-			|| (unsigned int)(action) > LZMA_FINISH
+			|| (unsigned int)(action) > LZMA_ACTION_MAX
 			|| !strm->internal->supported_actions[action])
 		return LZMA_PROG_ERROR;
 
@@ -211,6 +211,10 @@ lzma_code(lzma_stream *strm, lzma_action action)
 		case LZMA_FINISH:
 			strm->internal->sequence = ISEQ_FINISH;
 			break;
+
+		case LZMA_FULL_BARRIER:
+			strm->internal->sequence = ISEQ_FULL_BARRIER;
+			break;
 		}
 
 		break;
@@ -238,6 +242,13 @@ lzma_code(lzma_stream *strm, lzma_action action)
 
 		break;
 
+	case ISEQ_FULL_BARRIER:
+		if (action != LZMA_FULL_BARRIER
+				|| strm->internal->avail_in != strm->avail_in)
+			return LZMA_PROG_ERROR;
+
+		break;
+
 	case ISEQ_END:
 		return LZMA_STREAM_END;
 
@@ -288,7 +299,9 @@ lzma_code(lzma_stream *strm, lzma_action action)
 
 	case LZMA_STREAM_END:
 		if (strm->internal->sequence == ISEQ_SYNC_FLUSH
-				|| strm->internal->sequence == ISEQ_FULL_FLUSH)
+				|| strm->internal->sequence == ISEQ_FULL_FLUSH
+				|| strm->internal->sequence
+					== ISEQ_FULL_BARRIER)
 			strm->internal->sequence = ISEQ_RUN;
 		else
 			strm->internal->sequence = ISEQ_END;
diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
index b71254d0..42d27d83 100644
--- a/src/liblzma/common/common.h
+++ b/src/liblzma/common/common.h
@@ -78,6 +78,10 @@
 	| LZMA_CONCATENATED )
 
 
+/// Largest valid lzma_action value as unsigned integer.
+#define LZMA_ACTION_MAX ((unsigned int)(LZMA_FULL_BARRIER))
+
+
 /// Special return value (lzma_ret) to indicate that a timeout was reached
 /// and lzma_code() must not return LZMA_BUF_ERROR. This is converted to
 /// LZMA_OK in lzma_code(). This is not in the lzma_ret enumeration because
@@ -207,6 +211,7 @@ struct lzma_internal_s {
 		ISEQ_SYNC_FLUSH,
 		ISEQ_FULL_FLUSH,
 		ISEQ_FINISH,
+		ISEQ_FULL_BARRIER,
 		ISEQ_END,
 		ISEQ_ERROR,
 	} sequence;
@@ -217,7 +222,7 @@ struct lzma_internal_s {
 	size_t avail_in;
 
 	/// Indicates which lzma_action values are allowed by next.code.
-	bool supported_actions[4];
+	bool supported_actions[LZMA_ACTION_MAX + 1];
 
 	/// If true, lzma_code will return LZMA_BUF_ERROR if no progress was
 	/// made (no input consumed and no output produced by next.code).
diff --git a/src/liblzma/common/stream_encoder.c b/src/liblzma/common/stream_encoder.c
index df072d91..a7663bc4 100644
--- a/src/liblzma/common/stream_encoder.c
+++ b/src/liblzma/common/stream_encoder.c
@@ -146,11 +146,12 @@ stream_encode(lzma_coder *coder, const lzma_allocator *allocator,
 	}
 
 	case SEQ_BLOCK_ENCODE: {
-		static const lzma_action convert[4] = {
+		static const lzma_action convert[LZMA_ACTION_MAX + 1] = {
 			LZMA_RUN,
 			LZMA_SYNC_FLUSH,
 			LZMA_FINISH,
 			LZMA_FINISH,
+			LZMA_FINISH,
 		};
 
 		const lzma_ret ret = coder->block_encoder.code(
@@ -324,6 +325,7 @@ lzma_stream_encoder(lzma_stream *strm,
 	strm->internal->supported_actions[LZMA_RUN] = true;
 	strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true;
 	strm->internal->supported_actions[LZMA_FULL_FLUSH] = true;
+	strm->internal->supported_actions[LZMA_FULL_BARRIER] = true;
 	strm->internal->supported_actions[LZMA_FINISH] = true;
 
 	return LZMA_OK;