Fix a potential buffer overrun due to corrupt JSONB.

FossilOrigin-Name: 5cbb861fc6cb7421a81c957ba9d576e0ae92cb4ed725cdb539b364d66f4ee145

manifest

@@ -1,5 +1,5 @@
-C Fix\sbugs\suncovered\sby\sthe\sfuzzer.
-D 2023-10-10T18:04:40.744
+C Fix\sa\spotential\sbuffer\soverrun\sdue\sto\scorrupt\sJSONB.
+D 2023-10-10T18:32:14.227
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F LICENSE.md df5091916dbb40e6e9686186587125e1b2ff51f022cc334e886c19a0e9982724
@@ -674,7 +674,7 @@ F src/hash.h 3340ab6e1d13e725571d7cee6d3e3135f0779a7d8e76a9ce0a85971fa3953c51
 F src/hwtime.h f9c2dfb84dce7acf95ce6d289e46f5f9d3d1afd328e53da8f8e9008e3b3caae6
 F src/in-operator.md 10cd8f4bcd225a32518407c2fb2484089112fd71
 F src/insert.c 3f0a94082d978bbdd33c38fefea15346c6c6bffb70bc645a71dc0f1f87dd3276
-F src/json.c 7df84bb5b918dca3e9c4361989a3667bf1ca080299fdf9947e6f99b39d7523af
+F src/json.c e6e3641f54366634dc10dfb3684c3643821883b533f89c207b33dd2d23499c7d
 F src/legacy.c d7874bc885906868cd51e6c2156698f2754f02d9eee1bae2d687323c3ca8e5aa
 F src/loadext.c 98cfba10989b3da6f1807ad42444017742db7f100a54f1032af7a8b1295912c0
 F src/main.c 618aeb399e993cf561864f4b0cf6a331ee4f355cf663635f8d9da3193a46aa40
@@ -2129,8 +2129,8 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P f93f16c94d0a58dfa90939e84aba048be958c7b085b45a6f25c2243fdf79b3aa
-R 77f1fc6f77b161facff6daa6dc651655
+P c96eb7fb618dc0a5aeec8a5e85076475b77dcd56309438aba1f9bddfc8921e3c
+R 24c9be5529f36a58a40f05b718ffa50e
 U drh
-Z 2b3feb335f873a4bcfbf7b38cfcaa6e3
+Z 1fee0a4053cb04fe5ff07cf374f7fcdd
 # Remove this line to create a well-formed Fossil manifest.

manifest.uuid

@@ -1 +1 @@
-c96eb7fb618dc0a5aeec8a5e85076475b77dcd56309438aba1f9bddfc8921e3c
+5cbb861fc6cb7421a81c957ba9d576e0ae92cb4ed725cdb539b364d66f4ee145

src/json.c

@@ -1124,7 +1124,7 @@ static void jsonReturnFromNode(
       assert( pNode->eU==1 );
     to_double:
       z = pNode->u.zJContent;
-      sqlite3AtoF(z, &r, sqlite3Strlen30(z), SQLITE_UTF8);
+      sqlite3AtoF(z, &r, pNode->n, SQLITE_UTF8);
       sqlite3_result_double(pCtx, r);
       break;
     }