Fix LZ4_decompress_fast_continue() bug

It specified the external dictionary location incorrectly.
Add tests that expose this bug with both normal compilation and ASAN.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/lz4.c b/lib/lz4.c
index 6db4c0b..740ae64 100644
--- a/lib/lz4.c
+++ b/lib/lz4.c
@@ -1366,7 +1366,7 @@ int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const ch
         lz4sd->prefixEnd  += originalSize;
     } else {
         lz4sd->extDictSize = lz4sd->prefixSize;
-        lz4sd->externalDict = (BYTE*)dest - lz4sd->extDictSize;
+        lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
         result = LZ4_decompress_generic(source, dest, 0, originalSize,
                                         endOnOutputSize, full, 0,
                                         usingExtDict, (BYTE*)dest, lz4sd->externalDict, lz4sd->extDictSize);