--- sqlite3.c.orig	2019-03-09 21:21:39.522049549 +0300
+++ sqlite3.c	2019-01-16 21:46:55.113927913 +0300
@@ -27001,6 +27001,7 @@ SQLITE_PRIVATE int sqlite3ThreadJoin(SQL
     assert( rc!=WAIT_IO_COMPLETION );
     bRc = CloseHandle((HANDLE)p->tid);
     assert( bRc );
+    (void)bRc; /* Unused. */
   }
   if( rc==WAIT_OBJECT_0 ) *ppOut = p->pResult;
   sqlite3_free(p);
@@ -194485,7 +194486,7 @@ static int sqlite3Fts5IndexQuery(
 
   if( sqlite3Fts5BufferSize(&p->rc, &buf, nToken+1)==0 ){
     int iIdx = 0;                 /* Index to search */
-    memcpy(&buf.p[1], pToken, nToken);
+    if( nToken ) memcpy(&buf.p[1], pToken, nToken);
 
     /* Figure out which index to search and set iIdx accordingly. If this
     ** is a prefix query for which there is no prefix index, set iIdx to