rMayHaveNull     84588 ext/sqlite3/libsqlite/sqlite3.c     int rMayHaveNull = 0;
rMayHaveNull     84596 ext/sqlite3/libsqlite/sqlite3.c       *prRhsHasNull = rMayHaveNull = ++pParse->nMem;
rMayHaveNull     84598 ext/sqlite3/libsqlite/sqlite3.c     sqlite3CodeSubselect(pParse, pX, rMayHaveNull, eType==IN_INDEX_ROWID);