From 3294b780513a24b43ec6ad5839e75bc3021c9edf Mon Sep 17 00:00:00 2001
From: Jussi Saurio <jussi.saurio@gmail.com>
Date: Tue, 28 Oct 2025 13:08:05 +0200
Subject: [PATCH] Initialize LIMIT after after ORDER BY / GROUP BY
 initialization

Currently LIMIT 0 jumps to "after the main loop", and it is done
before ORDER BY and GROUP BY cursor have had a chance to be initialized,
which causes a panic.

Simplest fix for now is to delay the LIMIT initialization.
---
 core/translate/emitter.rs |  9 +++++----
 testing/select.test       | 16 +++++++++++++++-
 2 files changed, 20 insertions(+), 5 deletions(-)

diff --git a/core/translate/emitter.rs b/core/translate/emitter.rs
index db84007f0..237f037b3 100644
--- a/core/translate/emitter.rs
+++ b/core/translate/emitter.rs
@@ -272,8 +272,6 @@ pub fn emit_query<'a>(
     let after_main_loop_label = program.allocate_label();
     t_ctx.label_main_loop_end = Some(after_main_loop_label);
 
-    init_limit(program, t_ctx, &plan.limit, &plan.offset)?;
-
     if !plan.values.is_empty() {
         let reg_result_cols_start = emit_values(program, plan, t_ctx)?;
         program.preassign_label_to_next_insn(after_main_loop_label);
@@ -356,6 +354,9 @@ pub fn emit_query<'a>(
     if let Distinctness::Distinct { ctx } = &mut plan.distinctness {
         *ctx = distinct_ctx
     }
+
+    init_limit(program, t_ctx, &plan.limit, &plan.offset)?;
+
     init_loop(
         program,
         t_ctx,
@@ -2073,7 +2074,7 @@ fn init_limit(
                 _ => {
                     let r = limit_ctx.reg_limit;
 
-                    _ = translate_expr(program, None, expr, r, &t_ctx.resolver);
+                    _ = translate_expr(program, None, expr, r, &t_ctx.resolver)?;
                     program.emit_insn(Insn::MustBeInt { reg: r });
                 }
             }
@@ -2103,7 +2104,7 @@ fn init_limit(
                     }
                 }
                 _ => {
-                    _ = translate_expr(program, None, expr, offset_reg, &t_ctx.resolver);
+                    _ = translate_expr(program, None, expr, offset_reg, &t_ctx.resolver)?;
                 }
             }
             program.add_comment(program.offset(), "OFFSET counter");
diff --git a/testing/select.test b/testing/select.test
index 1267f131d..daa3e220b 100755
--- a/testing/select.test
+++ b/testing/select.test
@@ -1098,4 +1098,18 @@ do_execsql_test_on_specific_db {:memory:} unambiguous-self-join {
 2|3
 3|1
 3|2
-3|3}
\ No newline at end of file
+3|3}
+
+# Regression test for https://github.com/tursodatabase/turso/issues/3853
+do_execsql_test_on_specific_db {:memory:} order-by-limit-0 {
+    CREATE TABLE t(a);
+	INSERT INTO t VALUES (1), (2), (3); 
+	SELECT * FROM t ORDER BY a LIMIT 0;
+} {}
+
+# Regression test for https://github.com/tursodatabase/turso/issues/3853
+do_execsql_test_on_specific_db {:memory:} group-by-limit-0 {
+    CREATE TABLE t(a);
+	INSERT INTO t VALUES (1), (2), (3); 
+	SELECT a, COUNT(*) FROM t GROUP BY a LIMIT 0;
+} {}
\ No newline at end of file