Bug #68437 [NEW]: saveXML produces invalid xml

From: lphp-bug at thax dot hardliners dot org Operating system: PHP version: master-Git-2014-11-17 (Git) Package: DOM XML related Bug Type: Bug Bug description:saveXML produces invalid xml Description: ------------ Bug #54214 has been closed as Bogus, but gets the facts wrong: 1. XML (even the 1998 working drafts) defines valid chars as: Char ::= #x9 | #xA | #xD | [#x20-#xD7FF] | [#xE000-#xFFFD] | [#x10000-#x10FFFF] This contradicts #54214 that Char ::= [#x1-#xD7FF] | ... Thus, 0x0b (or 0x06) are actually not in the valid Range. 2. libxml2 "problem" is not saving low-ascii chars, but loading them: loadXML(saveXML()) ALWAYS fails, when e.g. DOMText with low-ascii is present: DOMDocument::loadXML(): xmlParseCharRef: invalid xmlChar value 11 in Entity 3. saveXML() does not always warn. More specifically, it only warns when (*) $doc has no encoding AND (**) saveXML() is called without arguments. 4. When saveXML() does warn, it will remove the offending character (good), but not when it does not warn. Background: - saveXML() uses xmlDocDumpFormatMemory(), which uses document encoding, when given. Otherwise ascii encoding (0x00 ... 0x7f only) is assumed, and xmlEscapeEntities (libxml2/tree/xmlsave.c, line 208) is used as escape-function. This function warns and ignores the offending character - saveXML($el) uses xmlNodeDump(), which passes encoding==NULL to xmlNodeDumpOuput, which converts NULL to "UTF-8". Then xmlSaveCtxtInit() will not set the escape-function. When the escape-function is not set on the xmlSaveCtxt, xmlOutputBufferWriteEscape will use xmlEscapeContent (libxml2/tree/xmlIO.c, line 3536) instead. This function does not warn, and happily includes 0x0b in the output (where finally loadXML chokes on it). Libxml never says that it will warn for low-ascii chars. Thus php-developers can't depend on it. OTOH, it's unfeasible to force every php-programmer to pre-sanitize strings sent into DOMText, or post-check the saved xml string. Therefore php has to provide the necessary means to avoid invalid xmls -- i.e. at the very least warn, or even better: throw already in DOMText. Test script: --------------- $doc=new DOMDocument('1.0','utf-8'); // or: $doc=new DOMDocument('1.0'); (*) $el=$doc->createElement('root'); $doc->appendChild($el); $el->appendChild(new DOMText("\x0b asdf")); $str=$doc->saveXML($el); // or: $doc->saveXML() (**) var_dump($str); $doc->loadXML($str); Expected result: ---------------- loadXML shall load the saved xml, or throw an exception earlier. Actual result: -------------- loadXML only works when (*) and (**) are used, i.e. when saveXML outputs a warning. -- Edit bug report at https://bugs.php.net/bug.php?id=68437&edit=1 -- Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=68437&r=trysnapshot54 Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=68437&r=trysnapshot55 Try a snapshot (trunk): https://bugs.php.net/fix.php?id=68437&r=trysnapshottrunk Fixed in SVN: https://bugs.php.net/fix.php?id=68437&r=fixed Fixed in release: https://bugs.php.net/fix.php?id=68437&r=alreadyfixed Need backtrace: https://bugs.php.net/fix.php?id=68437&r=needtrace Need Reproduce Script: https://bugs.php.net/fix.php?id=68437&r=needscript Try newer version: https://bugs.php.net/fix.php?id=68437&r=oldversion Not developer issue: https://bugs.php.net/fix.php?id=68437&r=support Expected behavior: https://bugs.php.net/fix.php?id=68437&r=notwrong Not enough info: https://bugs.php.net/fix.php?id=68437&r=notenoughinfo Submitted twice: https://bugs.php.net/fix.php?id=68437&r=submittedtwice register_globals: https://bugs.php.net/fix.php?id=68437&r=globals PHP 4 support discontinued: https://bugs.php.net/fix.php?id=68437&r=php4 Daylight Savings: https://bugs.php.net/fix.php?id=68437&r=dst IIS Stability: https://bugs.php.net/fix.php?id=68437&r=isapi Install GNU Sed: https://bugs.php.net/fix.php?id=68437&r=gnused Floating point limitations: https://bugs.php.net/fix.php?id=68437&r=float No Zend Extensions: https://bugs.php.net/fix.php?id=68437&r=nozend MySQL Configuration Error: https://bugs.php.net/fix.php?id=68437&r=mysqlcfg