qpdf-8.4.0

[Bruce Dubbs]

New minor version.

[Bruce Dubbs]

• Bug fix: do better pre-checks on images before optimizing; refuse to optimize images that can't be converted to JPEG because of colorspace or depth.

• Add new options --externalize-inline-images, which converts inline images larger than a specified size to regular images, and --ii-min-bytes, which tweaks that size.

• When optimizing images, inline images are now included in the optimization, first being converted to regular images. Use --keep-inline-images to exclude them from optimization.

• Add method QPDFPageObjectHelper::externalizeInlineImages, which converts inline images whose size is at least a specified amount to regular images.

• Remove traces of acroread, which hasn't been available in Linux for a long time.

• Do not include space after ID operator in inline image data. The token now correctly contains the image data, the EI operator, and the delimiter that precedes the EI operator.

• Improve locating of an inline image's EI operator to correctly handle the case of EI appearing inside the image data.

• Very low-level QPDFTokenizer API now includes an expectInlineImage method that takes an input stream, enabling it to locate an inline image's EI operator better. When this method is called, the inline image token returned will not contain the EI operator and will contain correct image data. This is called automatically everywhere within the qpdf library. Most user code will never have to use the low-level tokenizer API. If you use Pl_QPDFTokenizer, this will be done automatically for you. If you use the low-level API and call expectInlineImage, you should call the new version.

• Bug fix: when returning an inline image token, the tokenizer no longer includes the delimiter that follows EI. The QPDFObjectHandle created from the token was correct.

• Handle files with direct page objects, which is not allowed by the PDF spec but has been seen in the wild.

• Bug fix: when using --stream-data=compress, object streams and xref streams were not compressed. They were compressed if no --stream-data option was specified.

• When linearizing or getting the list of all pages in a file, replace duplicated page objects with a shallow copy of the page object. Linearization and all page manipulation APIs require page objects to be unique. Pages that were originally duplicated will still share contents and any other indirect resources.

• Add --overlay and --underlay options.

• Create examples/pdf-overlay-page.cc to demonstrate use of page/form XObject interaction

• Add new methods QPDFPageObjectHelper::getFormXObjectForPage, which creates a form XObject equivalent to a page, and QPDFObjectHandle::placeFormXObject, which generates content stream code to placing a form XObject on a page.

• Add new method QPDFObjectHandle::getUniqueResourceName() to return an unused key available to be used in a resource dictionary.

• Add new method QPDFPageObjectHelper::getAttribute() that properly handles inherited attributes and allows for creation of a copy of shared attributes. This is very useful if you are getting an attribute of a page dictionary with the intent to modify it privately for that page.

• Fix QPDFPageObjectHelper::getPageImages (and the legacy QPDFObjectHandle::getPageImages()) to properly handle images in inherited resources dictionaries.

• Tweak the content code generated for variable text fields to better handle font sizes and multi-line text.

• When generating appearance streams for variable text annotations, properly handle the cases of there being no appearance dictionary, no appearance stream, or an appearance stream with no BMC..EMC marker.

• When flattening annotations, remove annotations from the file that don't have appearance streams. These were previously being preserved, but since they are invisible, there is no reason to preserve them when flattening annotations.

• NOTE: qpdf CLI: some non-compatible changes were made to how qpdf interprets password arguments that contain Unicode characters that fall outside of ASCII. On Windows, the non-compatibility was unavoidable, as explained in the release notes. On all platforms, it is possible to get the old behavior if desired, though the old behavior would almost always result in files that other applications were unable to open. As it stands, qpdf should now be able to open passwords encrypted with a wide range of passwords that some other viewers might not handle, though even now, qpdf's Unicode password handling is not 100% complete.

• Add --password-mode option, which allows fine-grained control of how password arguments are treated. This is discussed fully in the manual.

• Add option --suppress-password-recovery to disable the behavior of searching for a correct password by re-encoding the provided password. This option can be useful if you want to ensure you know exactly what password is being used.

• When attempting to open an encrypted file with a password, if the password doesn't work, try alternative passwords created by re-interpreting the supplied password with different string encodings. This makes qpdf able to recover passwords with non-ASCII characters when either the decryption or encryption operation was performed with an incorrectly encoded password.

• Fix data loss bug: qpdf was discarding referenced resources in the case in which a page's resource dictionary contained an indirect reference for either /Font or /XObject that contained fonts or XObjects not referenced on all pages that shared the resource. This was a "typo" in the code. The comment explained the correct behavior, and the code was clearly intended to handle this issue, but the implementation had an error in it. This is fixed by a single-line change, which can be found in git commit 4bc434000c42a7191e705c8a38216ca6743ad9ff. That commit can be used as a patch that applies cleanly against qpdf 8.1.0 and forward. The bug was introduced in version 8.1.0. For the record, this is the first bug in qpdf's history that could result in silent loss of data when processing a correct input file.

• Add QUtil::possible_repaired_encodings which, given a string, generates other strings that represent re-interpretation of the bytes in a different coding system. This is used to help recover passwords if the password string was improperly encoded on a different system due to user error or a software bug.

• Add new CLI flags to 128-bit and 256-bit encryption: --assemble, --annotate, --form, and --modify-other to control encryption permissions with more granularity than was allowed with the --modify flag.

• Add new versions of QPDFWriter::setR{3,4,5,6}EncryptionParameters that allow individual setting of the various permission bits. The old interfaces are retained for backward compatibility. In the "C" API, add qpdf_set_r{3,4,5,6}_encryption_parameters2. The new interfaces use separate booleans for various permissions instead of the qpdf_r3_modify_e enumerated type, which set permission bits in predefined groups.

• Add versions of utf8 to single-byte character transcoders that return a success code.
• Add several more string transcoding and analysis methods to QUtil for bidirectional conversion between PDF Doc, Win Ansi, Mac Roman, UTF-6, and UTF-16 along with detection of valid UTF-8 and UTF-16.

• In the --pages option, allow the same page to be specified more than once. You can now do "--pages A.pdf 1,1 --" or "--pages A.pdf 1 A.pdf 1" instead of having to use two different paths to specify A.pdf.

• Add QPDFPageObjectHelper::shallowCopyPage(). This method creates a new page object that is a "shallow copy" of the given page as described in the comments in QPDFPageObjectHelper. The resulting object has not been added anywhere but is ready to be passed to QPDFPageDocumentHelper::addPage of its own QPDF or another QPDF object.

• Add QPDF::getUniqueId() method to return an identifier that is intended to be unique within the scope of all QPDF objects created by the calling application in a single run.

• In --pages, allow "." as a replacement for the current input file, making it possible to say "qpdf A.pdf --pages . 1-3 --" instead of having to repeat the input filename.

• Add new configure option --enable-avoid-windows-handle, which causes the symbol AVOID_WINDOWS_HANDLE to be defined. If set, we avoid using Windows I/O HANDLE, which is disallowed in some versions of the Windows SDK, such as for Windows phones. QUtil::same_file will always return false in this case. Only applies to Windows builds.

• Add new method QPDF::setImmediateCopyFrom. When called on a source QPDF object, streams can be copied FROM that object to other ones without having to keep the source QPDF or its input source around. The cost is copying the streams into RAM. See comments in QPDF.hh for setImmediateCopyFrom for a detailed explanation.

[Bruce Dubbs]

Fixed at revision 21080.