upstream fix for fts5 secure-delete corruption (cc0f82a480a400c6)

sjlombardo · sjlombardo · commit cb4a5a6bda87 · 2023-09-20T15:59:14.000-04:00
diff --git a/ext/fts5/fts5_index.c b/ext/fts5/fts5_index.c
@@ -4711,7 +4711,6 @@ static void fts5DoSecureDelete(
   int iIdx = 0;
   int iStart = 0;
   int iKeyOff = 0;
-  int iPrevKeyOff = 0;
   int iDelKeyOff = 0;       /* Offset of deleted key, if any */
 
   nIdx = nPg-iPgIdx;
@@ -4893,26 +4892,24 @@ static void fts5DoSecureDelete(
     }
 
     if( p->rc==SQLITE_OK ){
-      const int nMove = nPg - iNextOff;
-      int nShift = 0;
+      const int nMove = nPg - iNextOff;     /* Number of bytes to move */
+      int nShift = iNextOff - iOff;         /* Distance to move them */
+      int iPrevKeyOut = 0;
+      int iKeyIn = 0;
 
       memmove(&aPg[iOff], &aPg[iNextOff], nMove);
-      iPgIdx -= (iNextOff - iOff);
+      iPgIdx -= nShift;
       nPg = iPgIdx;
       fts5PutU16(&aPg[2], iPgIdx);
 
-      nShift = iNextOff - iOff;
-      for(iIdx=0, iKeyOff=0, iPrevKeyOff=0; iIdx<nIdx; /* no-op */){
+      for(iIdx=0; iIdx<nIdx; /* no-op */){
         u32 iVal = 0;
         iIdx += fts5GetVarint32(&aIdx[iIdx], iVal);
-        iKeyOff += iVal;
-        if( iKeyOff!=iDelKeyOff ){
-          if( iKeyOff>iOff ){
-            iKeyOff -= nShift;
-            nShift = 0;
-          }
-          nPg += sqlite3Fts5PutVarint(&aPg[nPg], iKeyOff - iPrevKeyOff);
-          iPrevKeyOff = iKeyOff;
+        iKeyIn += iVal;
+        if( iKeyIn!=iDelKeyOff ){
+          int iKeyOut = (iKeyIn - (iKeyIn>iOff ? nShift : 0));
+          nPg += sqlite3Fts5PutVarint(&aPg[nPg], iKeyOut - iPrevKeyOut);
+          iPrevKeyOut = iKeyOut;
         }
       }
 
diff --git a/ext/fts5/test/fts5secure.test b/ext/fts5/test/fts5secure.test
@@ -273,6 +273,19 @@ do_execsql_test 5.3 {
 do_execsql_test 5.4 { SELECT rowid FROM t1('abc'); } 2
 do_execsql_test 5.5 { SELECT rowid FROM t1('aa'); } 2
 
+#-------------------------------------------------------------------------
+reset_db
+
+do_execsql_test 6.0 {
+  CREATE VIRTUAL TABLE fts USING fts5(content);
+  INSERT INTO fts(fts, rank) VALUES ('secure-delete', 1);
+  INSERT INTO fts(rowid, content) VALUES
+    (3407, 'profile profile profile profile profile profile profile profile pull pulling pulling really');
+  DELETE FROM fts WHERE rowid IS 3407;
+  INSERT INTO fts(fts) VALUES ('integrity-check');
+}
+
+
 
 finish_test
 
