From 698a70e6a84cf7c0db667e9d9e021b4c34c85a3e Mon Sep 17 00:00:00 2001 From: m-holger Date: Wed, 24 May 2023 16:28:17 +0100 Subject: Code tidy - reflow comments and strings --- libqpdf/QPDFAcroFormDocumentHelper.cc | 329 ++++++++++++++-------------------- 1 file changed, 133 insertions(+), 196 deletions(-) (limited to 'libqpdf/QPDFAcroFormDocumentHelper.cc') diff --git a/libqpdf/QPDFAcroFormDocumentHelper.cc b/libqpdf/QPDFAcroFormDocumentHelper.cc index d210d50a..aca4bf1f 100644 --- a/libqpdf/QPDFAcroFormDocumentHelper.cc +++ b/libqpdf/QPDFAcroFormDocumentHelper.cc @@ -15,9 +15,8 @@ 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. + // 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(); } @@ -77,14 +76,11 @@ QPDFAcroFormDocumentHelper::addAndRenameFormFields(std::vector } 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. + // 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; @@ -253,8 +249,7 @@ QPDFAcroFormDocumentHelper::analyze() fields = QPDFObjectHandle::newArray(); } - // Traverse /AcroForm to find annotations and map them - // bidirectionally to fields. + // Traverse /AcroForm to find annotations and map them bidirectionally to fields. QPDFObjGen::set visited; int nfields = fields.getArrayNItems(); @@ -263,12 +258,10 @@ QPDFAcroFormDocumentHelper::analyze() 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 + // 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. @@ -278,13 +271,11 @@ QPDFAcroFormDocumentHelper::analyze() 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. + // 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); @@ -299,14 +290,14 @@ 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. + // 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"); + field.warnIfPossible("encountered a direct object as a field or annotation while " + "traversing /AcroForm; ignoring field or annotation"); return; } if (!field.isDictionary()) { @@ -322,13 +313,11 @@ QPDFAcroFormDocumentHelper::traverseField( 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. + // 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); @@ -363,8 +352,7 @@ QPDFAcroFormDocumentHelper::traverseField( 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 + // 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); } @@ -412,11 +400,9 @@ QPDFAcroFormDocumentHelper::generateAppearancesIfNeeded() 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 + // 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()); @@ -437,16 +423,13 @@ QPDFAcroFormDocumentHelper::adjustInheritedFields( 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. + // 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)) { @@ -550,45 +533,36 @@ 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. + // 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. + // * 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. + // * /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 + // 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()); @@ -599,8 +573,8 @@ QPDFAcroFormDocumentHelper::adjustDefaultAppearances( 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. + // 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"); @@ -620,15 +594,12 @@ 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. + // 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"); @@ -640,17 +611,15 @@ QPDFAcroFormDocumentHelper::adjustAppearanceStream( 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 + // 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. + // 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); @@ -662,12 +631,10 @@ QPDFAcroFormDocumentHelper::adjustAppearanceStream( 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. + // 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); } @@ -679,9 +646,8 @@ QPDFAcroFormDocumentHelper::adjustAppearanceStream( } } } - // 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. + // 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()) { @@ -702,8 +668,8 @@ QPDFAcroFormDocumentHelper::adjustAppearanceStream( 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. + // 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()); } } @@ -729,24 +695,22 @@ QPDFAcroFormDocumentHelper::transformAnnotations( } 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. + // 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. + // /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. + // 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; @@ -782,9 +746,8 @@ QPDFAcroFormDocumentHelper::transformAnnotations( } } - // 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. + // 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(); @@ -804,11 +767,9 @@ QPDFAcroFormDocumentHelper::transformAnnotations( 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. + // 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); @@ -818,8 +779,7 @@ QPDFAcroFormDocumentHelper::transformAnnotations( } }; - // This helper prevents us from copying the same object - // multiple times. + // 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(); @@ -842,39 +802,28 @@ QPDFAcroFormDocumentHelper::transformAnnotations( 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. + // 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(); @@ -886,36 +835,29 @@ QPDFAcroFormDocumentHelper::transformAnnotations( } 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. + // 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. + // 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. + // 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. + // Traverse the field, copying kids, and preserving integrity. std::list queue; QPDFObjGen::set seen; if (maybe_copy_object(top_field)) { @@ -933,8 +875,8 @@ QPDFAcroFormDocumentHelper::transformAnnotations( parent.warnIfPossible( "while traversing field " + obj.getObjGen().unparse(',') + ", found parent (" + parent_og.unparse(',') + - ") that had not been seen, indicating likely" - " invalid field structure"); + ") that had not been seen, indicating likely invalid field " + "structure"); } } auto kids = obj.getKey("/Kids"); @@ -955,17 +897,13 @@ QPDFAcroFormDocumentHelper::transformAnnotations( 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. + // 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); } @@ -1029,8 +967,7 @@ QPDFAcroFormDocumentHelper::transformAnnotations( } } - // Now we can safely mutate the annotation and its appearance - // streams. + // Now we can safely mutate the annotation and its appearance streams. for (auto& stream: streams) { auto dict = stream.getDict(); auto omatrix = dict.getKey("/Matrix"); -- cgit v1.2.3-70-g09d2