diff options
Diffstat (limited to 'libqpdf/QPDFObjectHandle.cc')
| -rw-r--r-- | libqpdf/QPDFObjectHandle.cc | 170 |
1 files changed, 120 insertions, 50 deletions
diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc index fcf9b976..7618cdf3 100644 --- a/libqpdf/QPDFObjectHandle.cc +++ b/libqpdf/QPDFObjectHandle.cc @@ -850,6 +850,11 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, bool in_array, bool in_dictionary, bool content_stream) { + // This method must take care not to resolve any objects. Don't + // check the tpye of any object without first ensuring that it is + // a direct object. Otherwise, doing so may have the side effect + // of reading the object and changing the file pointer. + empty = false; if (in_dictionary && in_array) { @@ -891,12 +896,13 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, case QPDFTokenizer::tt_brace_open: case QPDFTokenizer::tt_brace_close: - // Don't know what to do with these for now QTC::TC("qpdf", "QPDFObjectHandle bad brace"); - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - object_description, - input->getLastOffset(), - "unexpected brace token"); + warn(context, + QPDFExc(qpdf_e_damaged_pdf, input->getName(), + object_description, + input->getLastOffset(), + "treating unexpected brace token as null")); + object = newNull(); break; case QPDFTokenizer::tt_array_close: @@ -907,10 +913,12 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, else { QTC::TC("qpdf", "QPDFObjectHandle bad array close"); - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - object_description, - input->getLastOffset(), - "unexpected array close token"); + warn(context, + QPDFExc(qpdf_e_damaged_pdf, input->getName(), + object_description, + input->getLastOffset(), + "treating unexpected array close token as null")); + object = newNull(); } break; @@ -922,10 +930,12 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, else { QTC::TC("qpdf", "QPDFObjectHandle bad dictionary close"); - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - object_description, - input->getLastOffset(), - "unexpected dictionary close token"); + warn(context, + QPDFExc(qpdf_e_damaged_pdf, input->getName(), + object_description, + input->getLastOffset(), + "unexpected dictionary close token")); + object = newNull(); } break; @@ -1002,11 +1012,14 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, } else { - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - object_description, - input->getLastOffset(), - "unknown token while reading object (" + - value + ")"); + QTC::TC("qpdf", "QPDFObjectHandle treat word as string"); + warn(context, + QPDFExc(qpdf_e_damaged_pdf, input->getName(), + object_description, + input->getLastOffset(), + "unknown token while reading object;" + " treating as string")); + object = newString(value); } } break; @@ -1024,10 +1037,13 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, break; default: - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - object_description, - input->getLastOffset(), - "unknown token type while reading object"); + warn(context, + QPDFExc(qpdf_e_damaged_pdf, input->getName(), + object_description, + input->getLastOffset(), + "treating unknown token type as null while " + "reading object")); + object = newNull(); break; } @@ -1040,10 +1056,12 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, } else if (! object.isInitialized()) { - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - object_description, - input->getLastOffset(), - "parse error while reading object"); + warn(context, + QPDFExc(qpdf_e_damaged_pdf, input->getName(), + object_description, + input->getLastOffset(), + "parse error while reading object")); + object = newNull(); } else { @@ -1057,30 +1075,65 @@ QPDFObjectHandle::parseInternal(PointerHolder<InputSource> input, } else if (in_dictionary) { - // Convert list to map. Alternating elements are keys. - std::map<std::string, QPDFObjectHandle> dict; - if (olist.size() % 2) - { - QTC::TC("qpdf", "QPDFObjectHandle dictionary odd number of elements"); - throw QPDFExc( - qpdf_e_damaged_pdf, input->getName(), - object_description, input->getLastOffset(), - "dictionary ending here has an odd number of elements"); - } - for (unsigned int i = 0; i < olist.size(); i += 2) - { - QPDFObjectHandle key_obj = olist.at(i); - QPDFObjectHandle val = olist.at(i + 1); - if (! key_obj.isName()) - { - throw QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), object_description, offset, - std::string("dictionary key is not not a name token")); - } - dict[key_obj.getName()] = val; - } - object = newDictionary(dict); + // Convert list to map. Alternating elements are keys. Attempt + // to recover more or less gracefully from invalid + // dictionaries. + std::set<std::string> names; + for (std::vector<QPDFObjectHandle>::iterator iter = olist.begin(); + iter != olist.end(); ++iter) + { + if ((! (*iter).isIndirect()) && (*iter).isName()) + { + names.insert((*iter).getName()); + } + } + + std::map<std::string, QPDFObjectHandle> dict; + int next_fake_key = 1; + for (unsigned int i = 0; i < olist.size(); ++i) + { + QPDFObjectHandle key_obj = olist.at(i); + QPDFObjectHandle val; + if (key_obj.isIndirect() || (! key_obj.isName())) + { + bool found_fake = false; + std::string candidate; + while (! found_fake) + { + candidate = + "/QPDFFake" + QUtil::int_to_string(next_fake_key++); + found_fake = (names.count(candidate) == 0); + QTC::TC("qpdf", "QPDFObjectHandle found fake", + (found_fake ? 0 : 1)); + } + warn(context, + QPDFExc( + qpdf_e_damaged_pdf, + input->getName(), object_description, offset, + "expected dictionary key but found" + " non-name object; inserting key " + + candidate)); + val = key_obj; + key_obj = newName(candidate); + } + else if (i + 1 >= olist.size()) + { + QTC::TC("qpdf", "QPDFObjectHandle no val for last key"); + warn(context, + QPDFExc( + qpdf_e_damaged_pdf, + input->getName(), object_description, offset, + "dictionary ended prematurely; using null as value" + " for last key")); + val = newNull(); + } + else + { + val = olist.at(++i); + } + dict[key_obj.getName()] = val; + } + object = newDictionary(dict); } return object; @@ -1544,3 +1597,20 @@ QPDFObjectHandle::dereference() } } } + +void +QPDFObjectHandle::warn(QPDF* qpdf, QPDFExc const& e) +{ + // If parsing on behalf of a QPDF object and want to give a + // warning, we can warn through the object. If parsing for some + // other reason, such as an explicit creation of an object from a + // string, then just throw the exception. + if (qpdf) + { + QPDF::Warner::warn(qpdf, e); + } + else + { + throw e; + } +} |