From 94e22bc07737e6b4ef0ba7a6a7c901a1c16d9edc Mon Sep 17 00:00:00 2001
From: drh <>
Date: Sat, 10 May 2025 17:09:53 +0000
Subject: Provide the SQLITE_BUG_COMPATIBLE_20250510 compile-time option that
 restores the JSON5 bug fixed in the previous check-in, in case some
 applications need it for legacy compatibility.

FossilOrigin-Name: 491cf31904fdbc9567b838d1ba27901e75f8ea3a117043017d08354bb09f9711
---
 src/json.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

(limited to 'src/json.c')

diff --git a/src/json.c b/src/json.c
index e1b019d78..ee4cf1cbc 100644
--- a/src/json.c
+++ b/src/json.c
@@ -1757,7 +1757,11 @@ json_parse_restart:
            || (c=='u' && jsonIs4Hex(&z[j+1])) ){
           if( opcode==JSONB_TEXT ) opcode = JSONB_TEXTJ;
         }else if( c=='\'' ||  c=='v' || c=='\n'
-           || (c=='0' && !sqlite3Isdigit(z[j+1]))
+#ifdef SQLITE_BUG_COMPATIBLE_20250510
+           || (c=='0')                            /* Legacy bug compatible */
+#else
+           || (c=='0' && !sqlite3Isdigit(z[j+1])) /* Correct implementation */
+#endif
            || (0xe2==(u8)c && 0x80==(u8)z[j+1]
                 && (0xa8==(u8)z[j+2] || 0xa9==(u8)z[j+2]))
            || (c=='x' && jsonIs2Hex(&z[j+1])) ){
@@ -2726,7 +2730,18 @@ static u32 jsonUnescapeOneChar(const char *z, u32 n, u32 *piOut){
     case 't': {   *piOut = '\t';  return 2; }
     case 'v': {   *piOut = '\v';  return 2; }
     case '0': {
+      /* JSON5 requires that the \0 escape not be followed by a digit.
+      ** But SQLite did not enforce this restriction in versions 3.42.0
+      ** through 3.49.2.  That was a bug.  But some applications might have
+      ** come to depend on that bug.  Use the SQLITE_BUG_COMPATIBLE_20250510
+      ** option to restore the old buggy behavior. */
+#ifdef SQLITE_BUG_COMPATIBLE_20250510
+      /* Legacy bug-compatible behavior */
+      *piOut = 0;
+#else
+      /* Correct behavior */
       *piOut = (n>2 && sqlite3Isdigit(z[2])) ? JSON_INVALID_CHAR : 0;
+#endif
       return 2;
     }
     case '\'':
-- 
cgit v1.2.3