commit 4b92574feb7be219aa8c89e3b7ae770a145ecbd8
author Nick Terrell <terrelln@fb.com> Mon Mar 19 17:54:04 2018 -0700
committer Nick Terrell <terrelln@fb.com> Mon Mar 19 17:54:04 2018 -0700
tree a2372c5c91c7748081fa51606dfbc4f9e51e3279
parent 94c77710a90c982ce22d776fa34ab5f3dc5e0446

Fix corner cases exposed by zstreamtest

lib/compress/zstdmt_compress.c

diff --git a/lib/compress/zstdmt_compress.c b/lib/compress/zstdmt_compress.c
index 3225f98..9d54da0 100644
--- a/lib/compress/zstdmt_compress.c
+++ b/lib/compress/zstdmt_compress.c
@@ -456,11 +456,11 @@
         ZSTD_window_clear(&serialState->ldmState.window);
         serialState->ldmWindow = serialState->ldmState.window;
         /* Resize tables and output space if necessary. */
-        if (serialState->params.ldmParams.hashLog < hashLog) {
+        if (serialState->ldmState.hashTable == NULL || serialState->params.ldmParams.hashLog < hashLog) {
             ZSTD_free(serialState->ldmState.hashTable, cMem);
             serialState->ldmState.hashTable = (ldmEntry_t*)ZSTD_malloc(hashSize, cMem);
         }
-        if (prevBucketLog < bucketLog) {
+        if (serialState->ldmState.bucketOffsets == NULL || prevBucketLog < bucketLog) {
             ZSTD_free(serialState->ldmState.bucketOffsets, cMem);
             serialState->ldmState.bucketOffsets = (BYTE*)ZSTD_malloc(bucketSize, cMem);
         }
@@ -1591,6 +1591,9 @@
 
     if (rangeStart == NULL || bufferStart == NULL)
         return 0;
+    /* Empty ranges cannot overlap */
+    if (bufferStart == bufferEnd || rangeStart == rangeEnd)
+        return 0;
 
     return bufferStart < rangeEnd && rangeStart < bufferEnd;
 }