fix #783

LZ4_decompress_safe_partial()
now also supports a scenario where
nb_bytes_to_generate is <= block_decompressed_size
And
nb_bytes_to_read is >= block_compressed_size.

Previously, the only supported scenario was
nb_bytes_to_read == block_compress_size.

Pay attention that,
if nb_bytes_to_read is > block_compressed_size,
then, necessarily, it requires that
nb_bytes_to_generate is <= block_decompress_size.
If both are larger, it will generate corrupted data.

1 files changed, 4 insertions, 4 deletions

diff --git a/tests/fuzzer.c b/tests/fuzzer.c
index cbb53ca..beeb9d6 100644
--- a/tests/fuzzer.c
+++ b/tests/fuzzer.c
@@ -618,13 +618,13 @@ static int FUZ_test(U32 seed, U32 nbCycles, const U32 startCycle, const double c
 
         /* Test partial decoding => must work */
         FUZ_DISPLAYTEST("test LZ4_decompress_safe_partial");
-        {   size_t const missingBytes = FUZ_rand(&randState) % (unsigned)blockSize;
-            int const targetSize = (int)((size_t)blockSize - missingBytes);
+        {   size_t const missingOutBytes = FUZ_rand(&randState) % (unsigned)blockSize;
+            int const targetSize = (int)((size_t)blockSize - missingOutBytes);
             size_t const extraneousInBytes = FUZ_rand(&randState) % 2;
             int const inCSize = (int)((size_t)compressedSize + extraneousInBytes);
             char const sentinel = decodedBuffer[targetSize] = block[targetSize] ^ 0x5A;
-            //DISPLAY("compressedSize=%i, inCSize=%i \n", compressedSize, inCSize);
-            //DISPLAY("decompressedSize=%i, targetDstSize=%i \n", blockSize, targetSize);
+            DISPLAYLEVEL(6,"compressedSize=%i, inCSize=%i \n", compressedSize, inCSize);
+            DISPLAYLEVEL(6,"decompressedSize=%i, targetDstSize=%i \n", blockSize, targetSize);
             int const decResult = LZ4_decompress_safe_partial(compressedBuffer, decodedBuffer, inCSize, targetSize, blockSize);
             FUZ_CHECKTEST(decResult<0, "LZ4_decompress_safe_partial failed despite valid input data (error:%i)", decResult);
             FUZ_CHECKTEST(decResult != targetSize, "LZ4_decompress_safe_partial did not regenerated required amount of data (%i < %i <= %i)", decResult, targetSize, blockSize);