From b28958cef929728fa9e6f30f4c813b2ee337f271 Mon Sep 17 00:00:00 2001
From: Kyle Carberry <kyle@coder.com>
Date: Wed, 4 Mar 2026 22:35:52 -0500
Subject: [PATCH] Revert "fix(chatd): sanitize \u0000 from JSON before JSONB
 insertion" (#22645)

Reverts coder/coder#22637
---
 coderd/chatd/chatprompt/chatprompt.go      | 19 ----------------
 coderd/chatd/chatprompt/chatprompt_test.go | 25 ----------------------
 2 files changed, 44 deletions(-)

diff --git a/coderd/chatd/chatprompt/chatprompt.go b/coderd/chatd/chatprompt/chatprompt.go
index 88c2c9f90f..ff6ad99368 100644
--- a/coderd/chatd/chatprompt/chatprompt.go
+++ b/coderd/chatd/chatprompt/chatprompt.go
@@ -1,7 +1,6 @@
 package chatprompt
 
 import (
-	"bytes"
 	"encoding/json"
 	"regexp"
 	"strings"
@@ -423,7 +422,6 @@ func MarshalContent(blocks []fantasy.Content) (pqtype.NullRawMessage, error) {
 	if err != nil {
 		return pqtype.NullRawMessage{}, xerrors.Errorf("encode content blocks: %w", err)
 	}
-	data = sanitizeJSONForPG(data)
 	return pqtype.NullRawMessage{RawMessage: data, Valid: true}, nil
 }
 
@@ -441,7 +439,6 @@ func MarshalToolResult(toolCallID, toolName string, result json.RawMessage, isEr
 	if err != nil {
 		return pqtype.NullRawMessage{}, xerrors.Errorf("encode tool result: %w", err)
 	}
-	data = sanitizeJSONForPG(data)
 	return pqtype.NullRawMessage{RawMessage: data, Valid: true}, nil
 }
 
@@ -838,22 +835,6 @@ func sanitizeToolCallID(id string) string {
 	return toolCallIDSanitizer.ReplaceAllString(id, "_")
 }
 
-// jsonNullEscape is the JSON escape sequence for Unicode null (U+0000).
-var jsonNullEscape = []byte(`\u0000`)
-
-// sanitizeJSONForPG strips \u0000 escape sequences from JSON data.
-// PostgreSQL's jsonb type rejects the Unicode null character (U+0000)
-// with "unsupported Unicode escape sequence", even though \u0000 is
-// valid JSON per RFC 8259. Tool results from agents may contain this
-// sequence (e.g. binary data or C-style strings), so we strip it
-// before insertion.
-func sanitizeJSONForPG(data []byte) []byte {
-	if bytes.Contains(data, jsonNullEscape) {
-		data = bytes.ReplaceAll(data, jsonNullEscape, nil)
-	}
-	return data
-}
-
 func marshalContentBlock(block fantasy.Content) (json.RawMessage, error) {
 	encoded, err := json.Marshal(block)
 	if err != nil {
diff --git a/coderd/chatd/chatprompt/chatprompt_test.go b/coderd/chatd/chatprompt/chatprompt_test.go
index 684e9c2328..ba398446a1 100644
--- a/coderd/chatd/chatprompt/chatprompt_test.go
+++ b/coderd/chatd/chatprompt/chatprompt_test.go
@@ -1,7 +1,6 @@
 package chatprompt_test
 
 import (
-	"bytes"
 	"encoding/json"
 	"testing"
 
@@ -90,27 +89,3 @@ func TestConvertMessages_NormalizesAssistantToolCallInput(t *testing.T) {
 		})
 	}
 }
-
-func TestMarshalToolResult_SanitizesNullBytes(t *testing.T) {
-	t.Parallel()
-
-	result := json.RawMessage(`{"output":"hello\u0000world"}`)
-	got, err := chatprompt.MarshalToolResult("call_1", "my_tool", result, false)
-	require.NoError(t, err)
-	require.True(t, got.Valid)
-	require.False(t, bytes.Contains(got.RawMessage, []byte(`\u0000`)),
-		"output should not contain \\u0000 escape sequences")
-}
-
-func TestMarshalContent_SanitizesNullBytes(t *testing.T) {
-	t.Parallel()
-
-	blocks := []fantasy.Content{
-		fantasy.TextContent{Text: "before\u0000after"},
-	}
-	got, err := chatprompt.MarshalContent(blocks)
-	require.NoError(t, err)
-	require.True(t, got.Valid)
-	require.False(t, bytes.Contains(got.RawMessage, []byte(`\u0000`)),
-		"output should not contain \\u0000 escape sequences")
-}