Fix undefined behavior when srcSize==1

2017-08-22 11:55:42 -07:00
parent 78c3d16bf4
commit e50ed1fa3a
3 changed files with 37 additions and 30 deletions
@@ -497,7 +497,8 @@ ZSTD_compressionParameters ZSTD_adjustCParams_internal(ZSTD_compressionParameter
    {   U32 const minSrcSize = (srcSize==0) ? 500 : 0;
        U64 const rSize = srcSize + dictSize + minSrcSize;
        if (rSize < ((U64)1<<ZSTD_WINDOWLOG_MAX)) {
-            U32 const srcLog = MAX(ZSTD_HASHLOG_MIN, ZSTD_highbit32((U32)(rSize)-1) + 1);
+            U32 const srcLog =
+                    MAX(ZSTD_HASHLOG_MIN, (rSize==1) ? 1 : ZSTD_highbit32((U32)(rSize)-1) + 1);
            if (cPar.windowLog > srcLog) cPar.windowLog = srcLog;
    }   }
    if (cPar.hashLog > cPar.windowLog) cPar.hashLog = cPar.windowLog;