1 files changed, 16 insertions, 15 deletions

diff --git a/ext/fts3/fts3_write.c b/ext/fts3/fts3_write.c
index a6b45aef2..203b48e2d 100644
--- a/ext/fts3/fts3_write.c
+++ b/ext/fts3/fts3_write.c
@@ -696,7 +696,7 @@ static int fts3PendingListAppend(
   assert( !p || p->iLastDocid<=iDocid );
 
   if( !p || p->iLastDocid!=iDocid ){
-    sqlite3_int64 iDelta = iDocid - (p ? p->iLastDocid : 0);
+    u64 iDelta = (u64)iDocid - (u64)(p ? p->iLastDocid : 0);
     if( p ){
       assert( p->nData<p->nSpace );
       assert( p->aData[p->nData]==0 );
@@ -1531,18 +1531,18 @@ static int fts3SegReaderNextDocid(
     }else{
       rc = fts3SegReaderRequire(pReader, p, FTS3_VARINT_MAX);
       if( rc==SQLITE_OK ){
-        sqlite3_int64 iDelta;
-        pReader->pOffsetList = p + sqlite3Fts3GetVarint(p, &iDelta);
+        u64 iDelta;
+        pReader->pOffsetList = p + sqlite3Fts3GetVarintU(p, &iDelta);
         if( pTab->bDescIdx ){
-          pReader->iDocid -= iDelta;
+          pReader->iDocid = (i64)((u64)pReader->iDocid - iDelta);
         }else{
-          pReader->iDocid += iDelta;
+          pReader->iDocid = (i64)((u64)pReader->iDocid + iDelta);
         }
       }
     }
   }
 
-  return SQLITE_OK;
+  return rc;
 }
 
 
@@ -2281,6 +2281,7 @@ static int fts3SegWriterAdd(
     int rc;
 
     /* The current leaf node is full. Write it out to the database. */
+    if( pWriter->iFree==LARGEST_INT64 ) return FTS_CORRUPT_VTAB;
     rc = fts3WriteSegment(p, pWriter->iFree++, pWriter->aData, nData);
     if( rc!=SQLITE_OK ) return rc;
     p->nLeafAdd++;
@@ -2978,10 +2979,10 @@ int sqlite3Fts3SegReaderStep(
           sqlite3_int64 iDelta;
           if( p->bDescIdx && nDoclist>0 ){
             if( iPrev<=iDocid ) return FTS_CORRUPT_VTAB;
-            iDelta = iPrev - iDocid;
+            iDelta = (i64)((u64)iPrev - (u64)iDocid);
           }else{
             if( nDoclist>0 && iPrev>=iDocid ) return FTS_CORRUPT_VTAB;
-            iDelta = iDocid - iPrev;
+            iDelta = (i64)((u64)iDocid - (u64)iPrev);
           }
 
           nByte = sqlite3Fts3VarintLen(iDelta) + (isRequirePos?nList+1:0);
@@ -3264,7 +3265,7 @@ static int fts3SegmentMerge(
         csr.zTerm, csr.nTerm, csr.aDoclist, csr.nDoclist);
   }
   if( rc!=SQLITE_OK ) goto finished;
-  assert( pWriter || bIgnoreEmpty );
+  assert_fts3_nc( pWriter || bIgnoreEmpty );
 
   if( iLevel!=FTS3_SEGCURSOR_PENDING ){
     rc = fts3DeleteSegdir(
@@ -5190,12 +5191,12 @@ static u64 fts3ChecksumIndex(
 
       i64 iDocid = 0;
       i64 iCol = 0;
-      i64 iPos = 0;
+      u64 iPos = 0;
 
       pCsr += sqlite3Fts3GetVarint(pCsr, &iDocid);
       while( pCsr<pEnd ){
-        i64 iVal = 0;
-        pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);
+        u64 iVal = 0;
+        pCsr += sqlite3Fts3GetVarintU(pCsr, &iVal);
         if( pCsr<pEnd ){
           if( iVal==0 || iVal==1 ){
             iCol = 0;
@@ -5203,11 +5204,11 @@ static u64 fts3ChecksumIndex(
             if( iVal ){
               pCsr += sqlite3Fts3GetVarint(pCsr, &iCol);
             }else{
-              pCsr += sqlite3Fts3GetVarint(pCsr, &iVal);
+              pCsr += sqlite3Fts3GetVarintU(pCsr, &iVal);
               if( p->bDescIdx ){
-                iDocid -= iVal;
+                iDocid = (i64)((u64)iDocid - iVal);
               }else{
-                iDocid += iVal;
+                iDocid = (i64)((u64)iDocid + iVal);
               }
             }
           }else{