Bug #52829 [Opn->Ana]: json_decode looses data

Edit report at http://bugs.php.net/bug.php?id=52829&edit=1 ID: 52829 Updated by: aharvey@php.net Reported by: pzbowen at gmail dot com Summary: json_decode looses data -Status: Open +Status: Analyzed Type: Bug Package: JSON related Operating System: Linux PHP Version: 5.2.14 Block user comment: N New Comment: The attached patch against trunk would cause the JSON parser to emit warnings for duplicate keys. The behaviour otherwise would be unchanged; the last value would be the one in the returned object/array. I'm holding off on committing it, though, for two reasons: 1. I'm not thrilled about emitting warnings, since they're difficult to handle. We could return false from json_decode() instead and add a return value to json_last_error() along the lines of JSON_ERROR_DUPLICATE_NAME, but that doesn't seem any better to me: I don't think this should stop decoding if the file is otherwise valid. 2. There is a performance impact from doing the extra checks. Cursory benchmarking would suggest it's on the order of a 5% slowdown in decoding speed. So, if we decide we can live with the speed hit, I'd still like to hear any bright ideas people might have for signalling these warnings in a way that's easy for users to handle and still allows decoding to succeed where possible. Previous Comments: ------------------------------------------------------------------------ [2010-09-14 07:48:42] aharvey@php.net The following patch has been added/updated: Patch Name: json-decode-warnings Revision: 1284443322 URL: http://bugs.php.net/patch-display.php?bug=52829&patch=json-decode-warnings&revision=1284443322 ------------------------------------------------------------------------ [2010-09-13 22:03:03] pzbowen at gmail dot com Agreed, no easy way to handle it, so it should return an error when this situation is encountered. ------------------------------------------------------------------------ [2010-09-13 21:49:13] kalle@php.net I can't see any really easy way to achieve this since properties and array keys are unique in PHP. Perhaps some overloading with objects but that would be dirty/hackish ------------------------------------------------------------------------ [2010-09-13 20:31:49] pzbowen at gmail dot com Description: ------------ According to RFC 4627, section 2.2, "The names within an object SHOULD be unique." This is only a SHOULD not a MUST, so the following is valid {"foo":2,"foo":3} Unfortunately in PHP this only returns the last object member. Test script: --------------- var_dump(json_decode('{"foo":2,"foo":3}')); Expected result: ---------------- an object with a way of accessing both members or an error raised by json_decode Actual result: -------------- object(stdClass)#1 (1) { ["foo"]=> int(3) } ------------------------------------------------------------------------ -- Edit this bug report at http://bugs.php.net/bug.php?id=52829&edit=1