commit 48405b46336007bcaa810e7a0f4af41d78ff9a2e
author senhuang42 <senhuang96@fb.com> Tue Nov 10 15:33:33 2020 -0500
committer senhuang42 <senhuang96@fb.com> Mon Nov 16 10:49:17 2020 -0500
tree 15ced868164ca6e2369e3d79349aa2f112d113b6
parent 022e6d81e73261fbcab63337105b261fad721442

Fix srcSize=0 edge case

lib/compress/zstd_compress.c

diff --git a/lib/compress/zstd_compress.c b/lib/compress/zstd_compress.c
index c19b243..98890c4 100644
--- a/lib/compress/zstd_compress.c
+++ b/lib/compress/zstd_compress.c
@@ -4694,6 +4694,16 @@
     BYTE* op = (BYTE*)dst;
 
     DEBUGLOG(4, "ZSTD_compressSequences_internal srcSize: %zu, inSeqsSize: %zu", srcSize, inSeqsSize);
+    /* Special case: empty frame */
+    if (remaining == 0) {
+        U32 const cBlockHeader24 = 1 /* last block */ + (((U32)bt_raw)<<1);
+        RETURN_ERROR_IF(dstCapacity<4, dstSize_tooSmall, "No room for empty frame block header");
+        MEM_writeLE32(op, cBlockHeader24);
+        op += ZSTD_blockHeaderSize;
+        dstCapacity -= ZSTD_blockHeaderSize;
+        cSize += ZSTD_blockHeaderSize;
+    }
+
     while (remaining) {
         U32 cBlockSize;
         int additionalByteAdjustment;