#include #include #include #include #include #include QPDFAcroFormDocumentHelper::Members::Members() : cache_valid(false) { } QPDFAcroFormDocumentHelper::QPDFAcroFormDocumentHelper(QPDF& qpdf) : QPDFDocumentHelper(qpdf), m(new Members()) { // We have to analyze up front. Otherwise, when we are adding annotations and fields, we are in // a temporarily unstable configuration where some widget annotations are not reachable. analyze(); } void QPDFAcroFormDocumentHelper::invalidateCache() { m->cache_valid = false; m->field_to_annotations.clear(); m->annotation_to_field.clear(); } bool QPDFAcroFormDocumentHelper::hasAcroForm() { return this->qpdf.getRoot().hasKey("/AcroForm"); } QPDFObjectHandle QPDFAcroFormDocumentHelper::getOrCreateAcroForm() { auto acroform = this->qpdf.getRoot().getKey("/AcroForm"); if (!acroform.isDictionary()) { acroform = this->qpdf.getRoot().replaceKeyAndGetNew( "/AcroForm", this->qpdf.makeIndirectObject(QPDFObjectHandle::newDictionary())); } return acroform; } void QPDFAcroFormDocumentHelper::addFormField(QPDFFormFieldObjectHelper ff) { auto acroform = getOrCreateAcroForm(); auto fields = acroform.getKey("/Fields"); if (!fields.isArray()) { fields = acroform.replaceKeyAndGetNew("/Fields", QPDFObjectHandle::newArray()); } fields.appendItem(ff.getObjectHandle()); QPDFObjGen::set visited; traverseField(ff.getObjectHandle(), QPDFObjectHandle::newNull(), 0, visited); } void QPDFAcroFormDocumentHelper::addAndRenameFormFields(std::vector fields) { analyze(); std::map renames; QPDFObjGen::set seen; for (std::list queue{fields.begin(), fields.end()}; !queue.empty(); queue.pop_front()) { auto& obj = queue.front(); if (seen.add(obj)) { auto kids = obj.getKey("/Kids"); if (kids.isArray()) { for (auto const& kid: kids.aitems()) { queue.push_back(kid); } } if (obj.hasKey("/T")) { // Find something we can append to the partial name that makes the fully qualified // name unique. When we find something, reuse the same suffix for all fields in this // group with the same name. We can only change the name of fields that have /T, and // this field's /T is always at the end of the fully qualified name, appending to /T // has the effect of appending the same thing to the fully qualified name. std::string old_name = QPDFFormFieldObjectHelper(obj).getFullyQualifiedName(); if (renames.count(old_name) == 0) { std::string new_name = old_name; int suffix = 0; std::string append; while (!getFieldsWithQualifiedName(new_name).empty()) { ++suffix; append = "+" + std::to_string(suffix); new_name = old_name + append; } renames[old_name] = append; } std::string append = renames[old_name]; if (!append.empty()) { obj.replaceKey( "/T", QPDFObjectHandle::newUnicodeString( obj.getKey("/T").getUTF8Value() + append)); } } } } for (auto const& i: fields) { addFormField(i); } } void QPDFAcroFormDocumentHelper::removeFormFields(std::set const& to_remove) { auto acroform = this->qpdf.getRoot().getKey("/AcroForm"); if (!acroform.isDictionary()) { return; } auto fields = acroform.getKey("/Fields"); if (!fields.isArray()) { return; } for (auto const& og: to_remove) { auto annotations = m->field_to_annotations.find(og); if (annotations != m->field_to_annotations.end()) { for (auto aoh: annotations->second) { m->annotation_to_field.erase(aoh.getObjectHandle().getObjGen()); } m->field_to_annotations.erase(og); } auto name = m->field_to_name.find(og); if (name != m->field_to_name.end()) { m->name_to_fields[name->second].erase(og); if (m->name_to_fields[name->second].empty()) { m->name_to_fields.erase(name->second); } m->field_to_name.erase(og); } } int i = 0; while (i < fields.getArrayNItems()) { auto field = fields.getArrayItem(i); if (to_remove.count(field.getObjGen())) { fields.eraseItem(i); } else { ++i; } } } void QPDFAcroFormDocumentHelper::setFormFieldName(QPDFFormFieldObjectHelper ff, std::string const& name) { ff.setFieldAttribute("/T", name); QPDFObjGen::set visited; auto ff_oh = ff.getObjectHandle(); traverseField(ff_oh, ff_oh.getKey("/Parent"), 0, visited); } std::vector QPDFAcroFormDocumentHelper::getFormFields() { analyze(); std::vector result; for (auto const& iter: m->field_to_annotations) { result.emplace_back(this->qpdf.getObject(iter.first)); } return result; } std::set QPDFAcroFormDocumentHelper::getFieldsWithQualifiedName(std::string const& name) { analyze(); // Keep from creating an empty entry auto iter = m->name_to_fields.find(name); if (iter != m->name_to_fields.end()) { return iter->second; } return {}; } std::vector QPDFAcroFormDocumentHelper::getAnnotationsForField(QPDFFormFieldObjectHelper h) { analyze(); std::vector result; QPDFObjGen og(h.getObjectHandle().getObjGen()); if (m->field_to_annotations.count(og)) { result = m->field_to_annotations[og]; } return result; } std::vector QPDFAcroFormDocumentHelper::getWidgetAnnotationsForPage(QPDFPageObjectHelper h) { return h.getAnnotations("/Widget"); } std::vector QPDFAcroFormDocumentHelper::getFormFieldsForPage(QPDFPageObjectHelper ph) { analyze(); QPDFObjGen::set todo; std::vector result; for (auto& annot: getWidgetAnnotationsForPage(ph)) { auto field = getFieldForAnnotation(annot).getTopLevelField(); if (todo.add(field) && field.getObjectHandle().isDictionary()) { result.push_back(field); } } return result; } QPDFFormFieldObjectHelper QPDFAcroFormDocumentHelper::getFieldForAnnotation(QPDFAnnotationObjectHelper h) { QPDFObjectHandle oh = h.getObjectHandle(); QPDFFormFieldObjectHelper result(QPDFObjectHandle::newNull()); if (!oh.isDictionaryOfType("", "/Widget")) { return result; } analyze(); QPDFObjGen og(oh.getObjGen()); if (m->annotation_to_field.count(og)) { result = m->annotation_to_field[og]; } return result; } void QPDFAcroFormDocumentHelper::analyze() { if (m->cache_valid) { return; } m->cache_valid = true; QPDFObjectHandle acroform = this->qpdf.getRoot().getKey("/AcroForm"); if (!(acroform.isDictionary() && acroform.hasKey("/Fields"))) { return; } QPDFObjectHandle fields = acroform.getKey("/Fields"); if (!fields.isArray()) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper fields not array"); acroform.warnIfPossible("/Fields key of /AcroForm dictionary is not an array; ignoring"); fields = QPDFObjectHandle::newArray(); } // Traverse /AcroForm to find annotations and map them bidirectionally to fields. QPDFObjGen::set visited; int nfields = fields.getArrayNItems(); QPDFObjectHandle null(QPDFObjectHandle::newNull()); for (int i = 0; i < nfields; ++i) { traverseField(fields.getArrayItem(i), null, 0, visited); } // All Widget annotations should have been encountered by traversing /AcroForm, but in case any // weren't, find them by walking through pages, and treat any widget annotation that is not // associated with a field as its own field. This just ensures that requesting the field for any // annotation we find through a page's /Annots list will have some associated field. Note that // a file that contains this kind of error will probably not // actually work with most viewers. for (auto const& ph: QPDFPageDocumentHelper(this->qpdf).getAllPages()) { for (auto const& iter: getWidgetAnnotationsForPage(ph)) { QPDFObjectHandle annot(iter.getObjectHandle()); QPDFObjGen og(annot.getObjGen()); if (m->annotation_to_field.count(og) == 0) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper orphaned widget"); // This is not supposed to happen, but it's easy enough for us to handle this case. // Treat the annotation as its own field. This could allow qpdf to sensibly handle a // case such as a PDF creator adding a self-contained annotation (merged with the // field dictionary) to the page's /Annots array and forgetting to also put it in // /AcroForm. annot.warnIfPossible("this widget annotation is not" " reachable from /AcroForm in the document catalog"); m->annotation_to_field[og] = QPDFFormFieldObjectHelper(annot); m->field_to_annotations[og].emplace_back(annot); } } } } void QPDFAcroFormDocumentHelper::traverseField( QPDFObjectHandle field, QPDFObjectHandle parent, int depth, QPDFObjGen::set& visited) { if (depth > 100) { // Arbitrarily cut off recursion at a fixed depth to avoid specially crafted files that // could cause stack overflow. return; } if (!field.isIndirect()) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper direct field"); field.warnIfPossible("encountered a direct object as a field or annotation while " "traversing /AcroForm; ignoring field or annotation"); return; } if (!field.isDictionary()) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper non-dictionary field"); field.warnIfPossible("encountered a non-dictionary as a field or annotation while" " traversing /AcroForm; ignoring field or annotation"); return; } QPDFObjGen og(field.getObjGen()); if (!visited.add(og)) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper loop"); field.warnIfPossible("loop detected while traversing /AcroForm"); return; } // A dictionary encountered while traversing the /AcroForm field may be a form field, an // annotation, or the merger of the two. A field that has no fields below it is a terminal. If a // terminal field looks like an annotation, it is an annotation because annotation dictionary // fields can be merged with terminal field dictionaries. Otherwise, the annotation fields might // be there to be inherited by annotations below it. bool is_annotation = false; bool is_field = (0 == depth); QPDFObjectHandle kids = field.getKey("/Kids"); if (kids.isArray()) { is_field = true; int nkids = kids.getArrayNItems(); for (int k = 0; k < nkids; ++k) { traverseField(kids.getArrayItem(k), field, 1 + depth, visited); } } else { if (field.hasKey("/Parent")) { is_field = true; } if (field.hasKey("/Subtype") || field.hasKey("/Rect") || field.hasKey("/AP")) { is_annotation = true; } } QTC::TC("qpdf", "QPDFAcroFormDocumentHelper field found", (depth == 0) ? 0 : 1); QTC::TC("qpdf", "QPDFAcroFormDocumentHelper annotation found", (is_field ? 0 : 1)); if (is_annotation) { QPDFObjectHandle our_field = (is_field ? field : parent); m->field_to_annotations[our_field.getObjGen()].emplace_back(field); m->annotation_to_field[og] = QPDFFormFieldObjectHelper(our_field); } if (is_field && (field.hasKey("/T"))) { QPDFFormFieldObjectHelper foh(field); auto f_og = field.getObjGen(); std::string name = foh.getFullyQualifiedName(); auto old = m->field_to_name.find(f_og); if (old != m->field_to_name.end()) { // We might be updating after a name change, so remove any old information std::string old_name = old->second; m->name_to_fields[old_name].erase(f_og); } m->field_to_name[f_og] = name; m->name_to_fields[name].insert(f_og); } } bool QPDFAcroFormDocumentHelper::getNeedAppearances() { bool result = false; QPDFObjectHandle acroform = this->qpdf.getRoot().getKey("/AcroForm"); if (acroform.isDictionary() && acroform.getKey("/NeedAppearances").isBool()) { result = acroform.getKey("/NeedAppearances").getBoolValue(); } return result; } void QPDFAcroFormDocumentHelper::setNeedAppearances(bool val) { QPDFObjectHandle acroform = this->qpdf.getRoot().getKey("/AcroForm"); if (!acroform.isDictionary()) { this->qpdf.getRoot().warnIfPossible( "ignoring call to QPDFAcroFormDocumentHelper::setNeedAppearances" " on a file that lacks an /AcroForm dictionary"); return; } if (val) { acroform.replaceKey("/NeedAppearances", QPDFObjectHandle::newBool(true)); } else { acroform.removeKey("/NeedAppearances"); } } void QPDFAcroFormDocumentHelper::generateAppearancesIfNeeded() { if (!getNeedAppearances()) { return; } for (auto const& page: QPDFPageDocumentHelper(this->qpdf).getAllPages()) { for (auto& aoh: getWidgetAnnotationsForPage(page)) { QPDFFormFieldObjectHelper ffh = getFieldForAnnotation(aoh); if (ffh.getFieldType() == "/Btn") { // Rather than generating appearances for button fields, rely on what's already // there. Just make sure /AS is consistent with /V, which we can do by resetting the // value of the field back to itself. This code is referenced in a comment in // QPDFFormFieldObjectHelper::generateAppearance. if (ffh.isRadioButton() || ffh.isCheckbox()) { ffh.setV(ffh.getValue()); } } else { ffh.generateAppearance(aoh); } } } setNeedAppearances(false); } void QPDFAcroFormDocumentHelper::adjustInheritedFields( QPDFObjectHandle obj, bool override_da, std::string const& from_default_da, bool override_q, int from_default_q) { // Override /Q or /DA if needed. If this object has a field type, directly or inherited, it is a // field and not just an annotation. In that case, we need to override if we are getting a value // from the document that is different from the value we would have gotten from the old // document. We must take care not to override an explicit value. It's possible that /FT may be // inherited by lower fields that may explicitly set /DA or /Q or that this is a field whose // type does not require /DA or /Q and we may be put a value on the field that is unused. This // is harmless, so it's not worth trying to work around. auto has_explicit = [](QPDFFormFieldObjectHelper& field, std::string const& key) { if (field.getObjectHandle().hasKey(key)) { return true; } auto oh = field.getInheritableFieldValue(key); if (!oh.isNull()) { return true; } return false; }; if (override_da || override_q) { QPDFFormFieldObjectHelper cur_field(obj); if (override_da && (!has_explicit(cur_field, "/DA"))) { std::string da = cur_field.getDefaultAppearance(); if (da != from_default_da) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper override da"); obj.replaceKey("/DA", QPDFObjectHandle::newUnicodeString(from_default_da)); } } if (override_q && (!has_explicit(cur_field, "/Q"))) { int q = cur_field.getQuadding(); if (q != from_default_q) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper override q"); obj.replaceKey("/Q", QPDFObjectHandle::newInteger(from_default_q)); } } } } namespace { class ResourceReplacer: public QPDFObjectHandle::TokenFilter { public: ResourceReplacer( std::map> const& dr_map, std::map>> const& rnames); ~ResourceReplacer() override = default; void handleToken(QPDFTokenizer::Token const&) override; private: size_t offset{0}; std::map> to_replace; }; } // namespace ResourceReplacer::ResourceReplacer( std::map> const& dr_map, std::map>> const& rnames) { // We have: // * dr_map[resource_type][key] == new_key // * rnames[resource_type][key] == set of offsets // // We want: // * to_replace[key][offset] = new_key for (auto const& rn_iter: rnames) { std::string const& rtype = rn_iter.first; auto dr_map_rtype = dr_map.find(rtype); if (dr_map_rtype == dr_map.end()) { continue; } auto const& key_offsets = rn_iter.second; for (auto const& ko_iter: key_offsets) { std::string const& old_key = ko_iter.first; auto dr_map_rtype_old = dr_map_rtype->second.find(old_key); if (dr_map_rtype_old == dr_map_rtype->second.end()) { continue; } auto const& offsets = ko_iter.second; for (auto const& o_iter: offsets) { to_replace[old_key][o_iter] = dr_map_rtype_old->second; } } } } void ResourceReplacer::handleToken(QPDFTokenizer::Token const& token) { bool wrote = false; if (token.getType() == QPDFTokenizer::tt_name) { std::string name = QPDFObjectHandle::newName(token.getValue()).getName(); if (to_replace.count(name) && to_replace[name].count(offset)) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper replaced DA token"); write(to_replace[name][offset]); wrote = true; } } this->offset += token.getRawValue().length(); if (!wrote) { writeToken(token); } } void QPDFAcroFormDocumentHelper::adjustDefaultAppearances( QPDFObjectHandle obj, std::map> const& dr_map) { // This method is called on a field that has been copied from another file but whose /DA still // refers to resources in the original file's /DR. // When appearance streams are generated for variable text fields (see ISO 32000 PDF spec // section 12.7.3.3), the field's /DA is used to generate content of the appearance stream. /DA // contains references to resources that may be resolved in the document's /DR dictionary, which // appears in the document's /AcroForm dictionary. For fields that we copied from other // documents, we need to ensure that resources are mapped correctly in the case of conflicting // names. For example, if a.pdf's /DR has /F1 pointing to one font and b.pdf's /DR also has /F1 // but it points elsewhere, we need to make sure appearance streams of fields copied from b.pdf // into a.pdf use whatever font /F1 meant in b.pdf, not whatever it means in a.pdf. This method // takes care of that. It is only called on fields copied from foreign files. // A few notes: // // * If the from document's /DR and the current document's /DR have conflicting keys, we have // already resolved the conflicts before calling this method. The dr_map parameter contains // the mapping from old keys to new keys. // // * /DA may be inherited from the document's /AcroForm dictionary. By the time this method has // been called, we have already copied any document-level values into the fields to avoid // having them inherit from the new document. This was done in adjustInheritedFields. auto DA = obj.getKey("/DA"); if (!DA.isString()) { return; } // Find names in /DA. /DA is a string that contains content stream-like code, so we create a // stream out of the string and then filter it. We don't attach the stream to anything, so it // will get discarded. ResourceFinder rf; auto da_stream = QPDFObjectHandle::newStream(&this->qpdf, DA.getUTF8Value()); try { auto nwarnings = this->qpdf.numWarnings(); da_stream.parseAsContents(&rf); if (this->qpdf.numWarnings() > nwarnings) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper /DA parse error"); } } catch (std::exception& e) { // No way to reproduce in test suite right now since error conditions are converted to // warnings. obj.warnIfPossible( std::string("Unable to parse /DA: ") + e.what() + "; this form field may not update properly"); return; } // Regenerate /DA by filtering its tokens. ResourceReplacer rr(dr_map, rf.getNamesByResourceType()); Pl_Buffer buf_pl("filtered DA"); da_stream.filterAsContents(&rr, &buf_pl); std::string new_da = buf_pl.getString(); obj.replaceKey("/DA", QPDFObjectHandle::newString(new_da)); } void QPDFAcroFormDocumentHelper::adjustAppearanceStream( QPDFObjectHandle stream, std::map> dr_map) { // We don't have to modify appearance streams or their resource dictionaries for them to display // properly, but we need to do so to make them save to regenerate. Suppose an appearance stream // as a font /F1 that is different from /F1 in /DR, and that when we copy the field, /F1 is // remapped to /F1_1. When the field is regenerated, /F1_1 won't appear in the stream's resource // dictionary, so the regenerated appearance stream will revert to the /F1_1 in /DR. If we // adjust existing appearance streams, we are protected from this problem. auto dict = stream.getDict(); auto resources = dict.getKey("/Resources"); // Make sure this stream has its own private resource dictionary. bool was_indirect = resources.isIndirect(); resources = resources.shallowCopy(); if (was_indirect) { resources = this->qpdf.makeIndirectObject(resources); } dict.replaceKey("/Resources", resources); // Create a dictionary with top-level keys so we can use mergeResources to force them to be // unshared. We will also use this to resolve conflicts that may already be in the resource // dictionary. auto merge_with = QPDFObjectHandle::newDictionary(); for (auto const& top_key: dr_map) { merge_with.replaceKey(top_key.first, QPDFObjectHandle::newDictionary()); } resources.mergeResources(merge_with); // Rename any keys in the resource dictionary that we remapped. for (auto const& i1: dr_map) { std::string const& top_key = i1.first; auto subdict = resources.getKey(top_key); if (!subdict.isDictionary()) { continue; } for (auto const& i2: i1.second) { std::string const& old_key = i2.first; std::string const& new_key = i2.second; auto existing_new = subdict.getKey(new_key); if (!existing_new.isNull()) { // The resource dictionary already has a key in it matching what we remapped an old // key to, so we'll have to move it out of the way. Stick it in merge_with, which we // will re-merge with the dictionary when we're done. We know merge_with already has // dictionaries for all the top keys. QTC::TC("qpdf", "QPDFAcroFormDocumentHelper ap conflict"); merge_with.getKey(top_key).replaceKey(new_key, existing_new); } auto existing_old = subdict.getKey(old_key); if (!existing_old.isNull()) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper ap rename"); subdict.replaceKey(new_key, existing_old); subdict.removeKey(old_key); } } } // Deal with any any conflicts by re-merging with merge_with and updating our local copy of // dr_map, which we will use to modify the stream contents. resources.mergeResources(merge_with, &dr_map); // Remove empty subdictionaries for (auto iter: resources.ditems()) { if (iter.second.isDictionary() && (iter.second.getKeys().size() == 0)) { resources.removeKey(iter.first); } } // Now attach a token filter to replace the actual resources. ResourceFinder rf; try { auto nwarnings = this->qpdf.numWarnings(); stream.parseAsContents(&rf); if (this->qpdf.numWarnings() > nwarnings) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper AP parse error"); } auto rr = new ResourceReplacer(dr_map, rf.getNamesByResourceType()); auto tf = std::shared_ptr(rr); stream.addTokenFilter(tf); } catch (std::exception& e) { // No way to reproduce in test suite right now since error conditions are converted to // warnings. stream.warnIfPossible(std::string("Unable to parse appearance stream: ") + e.what()); } } void QPDFAcroFormDocumentHelper::transformAnnotations( QPDFObjectHandle old_annots, std::vector& new_annots, std::vector& new_fields, std::set& old_fields, QPDFMatrix const& cm, QPDF* from_qpdf, QPDFAcroFormDocumentHelper* from_afdh) { std::shared_ptr afdhph; if (!from_qpdf) { // Assume these are from the same QPDF. from_qpdf = &this->qpdf; from_afdh = this; } else if ((from_qpdf != &this->qpdf) && (!from_afdh)) { afdhph = std::make_shared(*from_qpdf); from_afdh = afdhph.get(); } bool foreign = (from_qpdf != &this->qpdf); // It's possible that we will transform annotations that don't include any form fields. This // code takes care not to muck around with /AcroForm unless we have to. QPDFObjectHandle acroform = this->qpdf.getRoot().getKey("/AcroForm"); QPDFObjectHandle from_acroform = from_qpdf->getRoot().getKey("/AcroForm"); // /DA and /Q may be inherited from the document-level /AcroForm dictionary. If we are copying a // foreign stream and the stream is getting one of these values from its document's /AcroForm, // we will need to copy the value explicitly so that it doesn't start getting its default from // the destination document. bool override_da = false; bool override_q = false; std::string from_default_da; int from_default_q = 0; // If we copy any form fields, we will need to merge the source document's /DR into this // document's /DR. QPDFObjectHandle from_dr = QPDFObjectHandle::newNull(); if (foreign) { std::string default_da; int default_q = 0; if (acroform.isDictionary()) { if (acroform.getKey("/DA").isString()) { default_da = acroform.getKey("/DA").getUTF8Value(); } if (acroform.getKey("/Q").isInteger()) { default_q = acroform.getKey("/Q").getIntValueAsInt(); } } if (from_acroform.isDictionary()) { if (from_acroform.getKey("/DR").isDictionary()) { from_dr = from_acroform.getKey("/DR"); if (!from_dr.isIndirect()) { from_dr = from_qpdf->makeIndirectObject(from_dr); } from_dr = this->qpdf.copyForeignObject(from_dr); } if (from_acroform.getKey("/DA").isString()) { from_default_da = from_acroform.getKey("/DA").getUTF8Value(); } if (from_acroform.getKey("/Q").isInteger()) { from_default_q = from_acroform.getKey("/Q").getIntValueAsInt(); } } if (from_default_da != default_da) { override_da = true; } if (from_default_q != default_q) { override_q = true; } } // If we have to merge /DR, we will need a mapping of conflicting keys for rewriting /DA. Set // this up for lazy initialization in case we encounter any form fields. std::map> dr_map; bool initialized_dr_map = false; QPDFObjectHandle dr = QPDFObjectHandle::newNull(); auto init_dr_map = [&]() { if (!initialized_dr_map) { initialized_dr_map = true; // Ensure that we have a /DR that is an indirect // dictionary object. if (!acroform.isDictionary()) { acroform = getOrCreateAcroForm(); } dr = acroform.getKey("/DR"); if (!dr.isDictionary()) { dr = QPDFObjectHandle::newDictionary(); } dr.makeResourcesIndirect(this->qpdf); if (!dr.isIndirect()) { dr = acroform.replaceKeyAndGetNew("/DR", this->qpdf.makeIndirectObject(dr)); } // Merge the other document's /DR, creating a conflict map. mergeResources checks to // make sure both objects are dictionaries. By this point, if this is foreign, from_dr // has been copied, so we use the target qpdf as the owning qpdf. from_dr.makeResourcesIndirect(this->qpdf); dr.mergeResources(from_dr, &dr_map); if (from_afdh->getNeedAppearances()) { setNeedAppearances(true); } } }; // This helper prevents us from copying the same object multiple times. std::map orig_to_copy; auto maybe_copy_object = [&](QPDFObjectHandle& to_copy) { auto og = to_copy.getObjGen(); if (orig_to_copy.count(og)) { to_copy = orig_to_copy[og]; return false; } else { to_copy = this->qpdf.makeIndirectObject(to_copy.shallowCopy()); orig_to_copy[og] = to_copy; return true; } }; // Now do the actual copies. QPDFObjGen::set added_new_fields; for (auto annot: old_annots.aitems()) { if (annot.isStream()) { annot.warnIfPossible("ignoring annotation that's a stream"); continue; } // Make copies of annotations and fields down to the appearance streams, preserving all // internal referential integrity. When the incoming annotations are from a different file, // we first copy them locally. Then, whether local or foreign, we copy them again so that if // we bring the same annotation in multiple times (e.g. overlaying a foreign page onto // multiple local pages or a local page onto multiple other local pages), we don't create // annotations that are referenced in more than one place. If we did that, the effect of // applying transformations would be cumulative, which is definitely not what we want. // Besides, annotations and fields are not intended to be referenced in multiple places. // Determine if this annotation is attached to a form field. If so, the annotation may be // the same object as the form field, or the form field may have the annotation as a kid. In // either case, we have to walk up the field structure to find the top-level field. Within // one iteration through a set of annotations, we don't want to copy the same item more than // once. For example, suppose we have field A with kids B, C, and D, each of which has // annotations BA, CA, and DA. When we get to BA, we will find that BA is a kid of B which // is under A. When we do a copyForeignObject of A, it will also copy everything else // because of the indirect references. When we clone BA, we will want to clone A and then // update A's clone's kid to point B's clone and B's clone's parent to point to A's clone. // The same thing holds for annotations. Next, when we get to CA, we will again discover // that A is the top, but we don't want to re-copy A. We want CA's clone to be linked to the // same clone as BA's. Failure to do this will break up things like radio button groups, // which all have to kids of the same parent. auto ffield = from_afdh->getFieldForAnnotation(annot); auto ffield_oh = ffield.getObjectHandle(); QPDFObjectHandle top_field; bool have_field = false; bool have_parent = false; if (ffield_oh.isStream()) { ffield_oh.warnIfPossible("ignoring form field that's a stream"); } else if ((!ffield_oh.isNull()) && (!ffield_oh.isIndirect())) { ffield_oh.warnIfPossible("ignoring form field not indirect"); } else if (!ffield_oh.isNull()) { // A field and its associated annotation can be the same object. This matters because we // don't want to clone the annotation and field separately in this case. have_field = true; // Find the top-level field. It may be the field itself. top_field = ffield.getTopLevelField(&have_parent).getObjectHandle(); if (foreign) { // copyForeignObject returns the same value if called multiple times with the same // field. Create/retrieve the local copy of the original field. This pulls over // everything the field references including annotations and appearance streams, but // it's harmless to call copyForeignObject on them too. They will already be copied, // so we'll get the right object back. // top_field and ffield_oh are known to be indirect. top_field = this->qpdf.copyForeignObject(top_field); ffield_oh = this->qpdf.copyForeignObject(ffield_oh); } else { // We don't need to add top_field to old_fields if it's foreign because the new copy // of the foreign field won't be referenced anywhere. It's just the starting point // for us to make an additional local copy of. old_fields.insert(top_field.getObjGen()); } // Traverse the field, copying kids, and preserving integrity. std::list queue; QPDFObjGen::set seen; if (maybe_copy_object(top_field)) { queue.push_back(top_field); } for (; !queue.empty(); queue.pop_front()) { auto& obj = queue.front(); if (seen.add(obj)) { auto parent = obj.getKey("/Parent"); if (parent.isIndirect()) { auto parent_og = parent.getObjGen(); if (orig_to_copy.count(parent_og)) { obj.replaceKey("/Parent", orig_to_copy[parent_og]); } else { parent.warnIfPossible( "while traversing field " + obj.getObjGen().unparse(',') + ", found parent (" + parent_og.unparse(',') + ") that had not been seen, indicating likely invalid field " "structure"); } } auto kids = obj.getKey("/Kids"); if (kids.isArray()) { for (int i = 0; i < kids.getArrayNItems(); ++i) { auto kid = kids.getArrayItem(i); if (maybe_copy_object(kid)) { kids.setArrayItem(i, kid); queue.push_back(kid); } } } if (override_da || override_q) { adjustInheritedFields( obj, override_da, from_default_da, override_q, from_default_q); } if (foreign) { // Lazily initialize our /DR and the conflict map. init_dr_map(); // The spec doesn't say anything about /DR on the field, but lots of writers // put one there, and it is frequently the same as the document-level /DR. // To avoid having the field's /DR point to information that we are not // maintaining, just reset it to that if it exists. Empirical evidence // suggests that many readers, including Acrobat, Adobe Acrobat Reader, // chrome, firefox, the mac Preview application, and several of the free // readers on Linux all ignore /DR at the field level. if (obj.hasKey("/DR")) { obj.replaceKey("/DR", dr); } } if (foreign && obj.getKey("/DA").isString() && (!dr_map.empty())) { adjustDefaultAppearances(obj, dr_map); } } } // Now switch to copies. We already switched for top_field maybe_copy_object(ffield_oh); ffield = QPDFFormFieldObjectHelper(ffield_oh); } QTC::TC( "qpdf", "QPDFAcroFormDocumentHelper copy annotation", (have_field ? 1 : 0) | (foreign ? 2 : 0)); if (have_field) { QTC::TC( "qpdf", "QPDFAcroFormDocumentHelper field with parent", (have_parent ? 1 : 0) | (foreign ? 2 : 0)); } if (foreign) { if (!annot.isIndirect()) { annot = from_qpdf->makeIndirectObject(annot); } annot = this->qpdf.copyForeignObject(annot); } maybe_copy_object(annot); // Now we have copies, so we can safely mutate. if (have_field && added_new_fields.add(top_field)) { new_fields.push_back(top_field); } new_annots.push_back(annot); // Identify and copy any appearance streams auto ah = QPDFAnnotationObjectHelper(annot); auto apdict = ah.getAppearanceDictionary(); std::vector streams; auto replace_stream = [](auto& dict, auto& key, auto& old) { return dict.replaceKeyAndGetNew(key, old.copyStream()); }; if (apdict.isDictionary()) { for (auto& ap: apdict.ditems()) { if (ap.second.isStream()) { streams.push_back(replace_stream(apdict, ap.first, ap.second)); } else if (ap.second.isDictionary()) { for (auto& ap2: ap.second.ditems()) { if (ap2.second.isStream()) { streams.push_back( // line-break replace_stream(ap.second, ap2.first, ap2.second)); } } } } } // Now we can safely mutate the annotation and its appearance streams. for (auto& stream: streams) { auto dict = stream.getDict(); auto omatrix = dict.getKey("/Matrix"); QPDFMatrix apcm; if (omatrix.isArray()) { QTC::TC("qpdf", "QPDFAcroFormDocumentHelper modify ap matrix"); auto m1 = omatrix.getArrayAsMatrix(); apcm = QPDFMatrix(m1); } apcm.concat(cm); auto new_matrix = QPDFObjectHandle::newFromMatrix(apcm); if (omatrix.isArray() || (apcm != QPDFMatrix())) { dict.replaceKey("/Matrix", new_matrix); } auto resources = dict.getKey("/Resources"); if ((!dr_map.empty()) && resources.isDictionary()) { adjustAppearanceStream(stream, dr_map); } } auto rect = cm.transformRectangle(annot.getKey("/Rect").getArrayAsRectangle()); annot.replaceKey("/Rect", QPDFObjectHandle::newFromRectangle(rect)); } } void QPDFAcroFormDocumentHelper::fixCopiedAnnotations( QPDFObjectHandle to_page, QPDFObjectHandle from_page, QPDFAcroFormDocumentHelper& from_afdh, std::set* added_fields) { auto old_annots = from_page.getKey("/Annots"); if ((!old_annots.isArray()) || (old_annots.getArrayNItems() == 0)) { return; } std::vector new_annots; std::vector new_fields; std::set old_fields; transformAnnotations( old_annots, new_annots, new_fields, old_fields, QPDFMatrix(), &(from_afdh.getQPDF()), &from_afdh); to_page.replaceKey("/Annots", QPDFObjectHandle::newArray(new_annots)); addAndRenameFormFields(new_fields); if (added_fields) { for (auto const& f: new_fields) { added_fields->insert(f.getObjGen()); } } }