fparamsPtr->windowLog==0 means that a frame is skippable
diff --git a/lib/common/zstd_static.h b/lib/common/zstd_static.h
index e4c992b..19118f4 100644
--- a/lib/common/zstd_static.h
+++ b/lib/common/zstd_static.h
@@ -246,6 +246,15 @@
A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
Context can then be reset to start a new decompression.
+
+ Skippable frames allow the integration of user-defined data into a flow of concatenated frames.
+ Skippable frames will be ignored (skipped) by a decompressor. The format of skippable frame is following:
+ a) Skippable frame ID - 4 Bytes, Little endian format, any value from 0x184D2A50 to 0x184D2A5F
+ b) Frame Size - 4 Bytes, Little endian format, unsigned 32-bits
+ c) Frame Content - any content (User Data) of length equal to Frame Size
+ For skippable frames ZSTD_decompressContinue() always returns 0.
+ For skippable frames ZSTD_getFrameParams() returns fparamsPtr->windowLog==0 what means that a frame is skippable.
+ It also returns Frame Size as fparamsPtr->frameContentSize.
*/
diff --git a/lib/decompress/zbuff_decompress.c b/lib/decompress/zbuff_decompress.c
index 72456fd..69898fd 100644
--- a/lib/decompress/zbuff_decompress.c
+++ b/lib/decompress/zbuff_decompress.c
@@ -192,6 +192,8 @@
if (ZSTD_isError(h2Result)) return h2Result;
} }
+ if (zbd->fParams.windowLog < ZSTD_WINDOWLOG_ABSOLUTEMIN) zbd->fParams.windowLog = ZSTD_WINDOWLOG_ABSOLUTEMIN; /* required for buffer allocation */
+
/* Frame header instruct buffer sizes */
{ size_t const blockSize = MIN(1 << zbd->fParams.windowLog, ZSTD_BLOCKSIZE_MAX);
zbd->blockSize = blockSize;
diff --git a/lib/decompress/zstd_decompress.c b/lib/decompress/zstd_decompress.c
index e88b873..27dd780 100644
--- a/lib/decompress/zstd_decompress.c
+++ b/lib/decompress/zstd_decompress.c
@@ -335,7 +335,7 @@
if (srcSize < ZSTD_skippableHeaderSize) return ZSTD_skippableHeaderSize; /* magic number + skippable frame length */
memset(fparamsPtr, 0, sizeof(*fparamsPtr));
fparamsPtr->frameContentSize = MEM_readLE32((const char *)src + 4);
- fparamsPtr->windowLog = ZSTD_WINDOWLOG_ABSOLUTEMIN;
+ fparamsPtr->windowLog = 0; /* windowLog==0 means a frame is skippable */
return 0;
}
return ERROR(prefix_unknown);