liblzma: Make lzma_code() check the reserved members in lzma_stream.
If any of the reserved members in lzma_stream are non-zero
or non-NULL, LZMA_OPTIONS_ERROR is returned. It is possible
that a new feature in the future is indicated by just setting
a reserved member to some other value, so the old liblzma
version need to catch it as an unsupported feature.
diff --git a/src/liblzma/common/common.c b/src/liblzma/common/common.c
index 07b1d47..0408e15 100644
--- a/src/liblzma/common/common.c
+++ b/src/liblzma/common/common.c
@@ -182,6 +182,20 @@
|| !strm->internal->supported_actions[action])
return LZMA_PROG_ERROR;
+ // Check if unsupported members have been set to non-zero or non-NULL,
+ // which would indicate that some new feature is wanted.
+ if (strm->reserved_ptr1 != NULL
+ || strm->reserved_ptr2 != NULL
+ || strm->reserved_ptr3 != NULL
+ || strm->reserved_ptr4 != NULL
+ || strm->reserved_int1 != 0
+ || strm->reserved_int2 != 0
+ || strm->reserved_int3 != 0
+ || strm->reserved_int4 != 0
+ || strm->reserved_enum1 != LZMA_RESERVED_ENUM
+ || strm->reserved_enum2 != LZMA_RESERVED_ENUM)
+ return LZMA_OPTIONS_ERROR;
+
switch (strm->internal->sequence) {
case ISEQ_RUN:
switch (action) {
