2019-01-07  Jay Berkenbilt  <ejb@ql.org>

	* 8.3.0: release

	* Add sample completion files in completions. These can be used by
	packagers to install on the system wherever bash and zsh keep
	their vendor-supplied completions.

	* Add configure flag --enable-check-autofiles, which is on by
	default. Packagers whose packaging systems automatically refresh
	autoconf or libtool files should pass --disable-check-autofiles to
	./configure to suppress warnings about automatically generated
	files being outdated.

2019-01-06  Jay Berkenbilt  <ejb@ql.org>

	* Remove the restriction in most cases that the source QPDF used
	in a copyForeignObject call has to stick around until the
	destination QPDF is written. The exceptional case is when the
	source stream gets is data using a
	QPDFObjectHandle::StreamDataProvider. For a more in-depth
	discussion, see comments around copyForeignObject in QPDF.hh.
	Fixes #219.

2019-01-05  Jay Berkenbilt  <ejb@ql.org>

	* When generating appearances, if the font uses one of the
	standard, built-in encodings, restrict the character set to that
	rather than just to ASCII. This will allow most appearances to
	contain characters from the ISO-Latin-1 range plus a few
	additional characters.

	* Add methods QUtil::utf8_to_win_ansi and
	QUtil::utf8_to_mac_roman.

	* Add method QUtil::utf8_to_utf16.

2019-01-04  Jay Berkenbilt  <ejb@ql.org>

	* Add new option --optimize-images, which recompresses every image
	using DCT (JPEG) compression as long as the image is not already
	compressed with lossy compression and recompressing the image
	reduces its size. The additional options --oi-min-width,
	--oi-min-height, and --oi-min-area prevent recompression of images
	whose width, height, or pixel area (width * height) are below a
	specified threshold.

	* Add new option --collate. When specified, the semantics of
	--pages change from concatenation to collation. See the manual for
	a more detailed discussion. Fixes #259.

	* Add new method QPDFWriter::getFinalVersion, which returns the
	PDF version that will ultimately be written to the final file. See
	comments in QPDFWriter.hh for some restrictions on its use. Fixes
	#266.

	* When unexpected errors are found while checking linearization
	data, print an error message instead of calling assert, which
	cause the program to crash. Fixes #209, #231.

	* Detect and recover from dangling references. If a PDF file
	contained an indirect reference to a non-existent object (which is
	valid), when adding a new object to the file, it was possible for
	the new object to take the object ID of the dangling reference,
	thereby causing the dangling reference to point to the new object.
	This case is now prevented. Fixes #240.

2019-01-03  Jay Berkenbilt  <ejb@ql.org>

        * Add --generate-appearances flag to the qpdf command-line tool to
	trigger generation of appearance streams.

	* Fix behavior of form field value setting to handle the following
	cases:
	  - Strings are always written as UTF-16
	  - Check boxes and radio buttons are handled properly with
	    synchronization of values and appearance states

	* Define constants in qpdf/Constants.h for interpretation of
	annotation and form field flags

	* Add QPDFAnnotationObjectHelper::getFlags

	* Add many new methods to QPDFFormFieldObjectHelper for querying
	flags and field types

	* Add new methods for appearance stream generation. See comments
	in QPDFFormFieldObjectHelper.hh for generateAppearance() for a
	description of limitations.
	  - QPDFAcroFormDocumentHelper::generateAppearancesIfNeeded
	  - QPDFFormFieldObjectHelper::generateAppearance

	* Bug fix: when writing form field values, always write string
	values encoded as UTF-16.

	* Add method QUtil::utf8_to_ascii, which returns an ASCII string
	for a UTF-8 string, replacing out-of-range characters with a
	specified substitute.

2019-01-02  Jay Berkenbilt  <ejb@ql.org>

	* Add method QPDFObjectHandle::getResourceNames that returns a set
	of strings representing all second-level keys in a dictionary
	(i.e. all keys of all direct dictionary members).

2018-12-31  Jay Berkenbilt  <ejb@ql.org>

	* Add --flatten-annotations flag to the qpdf command-line tool for
	annotation flattening.

	* Add methods for flattening form fields and annotations:
	  - QPDFPageDocumentHelper::flattenAnnotations - integrate
	    annotation appearance streams into page contents with special
	    handling for form fields: if appearance streams are up to date
	    (/NeedAppearances is false in /AcroForm), the /AcroForm key of
	    the document catalog is removed. Otherwise, a warning is
	    issued, and form fields are ignored. Non-form-field
	    annotations are always flattened if an appearance stream can
	    be found.
	  - QPDFAnnotationObjectHelper::getPageContentForAppearance -
	    generate the content stream fragment to render an appearance
	    stream in a page's content stream as a form xobject. Called by
	    flattenAnnotations.

	* Add method QPDFObjectHandle::mergeResources(), which merges
	resource dictionaries. See detailed description in
	QPDFObjectHandle.hh.

	* Add QPDFObjectHandle::Matrix, similar to
	QPDFObjectHandle::Rectangle, as a convenience class for
	six-element arrays that are used as matrices.

2018-12-23  Jay Berkenbilt  <ejb@ql.org>

	* When specifying @arg on the command line, if the file "arg" does
	not exist, just treat this is a normal argument. This makes it
	easier to deal with files whose names start with the @ character.
	Fixes #265.

	* Tweak completion so it works with zsh as well using
	bashcompinit.

2018-12-22  Jay Berkenbilt  <ejb@ql.org>

	* Add new options --json, --json-key, and --json-object to
	generate a json representation of the PDF file. This is described
	in more depth in the manual. You can also run qpdf --json-help to
	get a description of the json format.

2018-12-21  Jay Berkenbilt  <ejb@ql.org>

	* Allow --show-object=trailer for showing the document trailer.

	* You can now use eval $(qpdf --completion-bash) to enable bash
	completion for qpdf. It's not perfect, but it works pretty well.

2018-12-19  Jay Berkenbilt  <ejb@ql.org>

	* When splitting pages using --split-pages, the outlines
	dictionary and some supporting metadata are copied into the split
	files. The result is that all bookmarks from the original file
	appear, and those that point to pages that are preserved work
	while those that point to pages that are not preserved don't do
	anything. This is an interim step toward proper support for
	bookmark preservation in split files.

	* Add QPDFOutlineDocumentHelper and QPDFOutlineObjectHelper for
	handling outlines (bookmarks) including bidirectionally mapping
	between bookmarks and pages. Initially there is no support for
	modifying the outlines hierarchy.

2018-12-18  Jay Berkenbilt  <ejb@ql.org>

	* New method QPDFObjectHandle::getJSON() returns a JSON object
	with a partial representation of the object. See
	QPDFObjectHandle.hh for a detailed description.

	* Add a simple JSON serializer. This is not a complete or
	general-purpose JSON library. It allows assembly and serialization
	of JSON structures with some restrictions, which are described in
	the header file.

	* Add QPDFNameTreeObjectHelper class. This class provides useful
	methods for dealing with name trees, which are discussed in
	section 7.9.6 of the PDF spec (ISO-32000).

	* Preserve page labels when merging and splitting files. Prior
	versions of qpdf simply preserved the page label information from
	the first file, which usually wouldn't make any sense in the
	merged file. Now any page that had a page number in any original
	file will have the same page number after merging or splitting.

	* Add QPDFPageLabelDocumentHelper class. This is a document helper
	class that provides useful methods for dealing with page labels.
	It abstracts the fact that they are stored as number trees and
	deals with interpolating intermediate values that are not in the
	tree. It also has helper functions used by the qpdf command line
	tool to preserve page labels when merging and splitting files.

	* Add QPDFNumberTreeObjectHelper class. This class provides useful
	methods for dealing with number trees, which are discussed in
	section 7.9.7 of the PDF spec (ISO-32000). Page label dictionaries
	are represented as number trees.

	* New method QPDFObjectHandle::wrapInArray returns the object
	itself if it is an array. Otherwise, it returns an array
	containing the object. This is useful for dealing with PDF data
	that is sometimes expressed as a single element and sometimes
	expressed as an array, which is a somewhat common PDF idiom.

2018-10-11  Jay Berkenbilt  <ejb@ql.org>

	* Files generated by autogen.sh are now committed so that it is
	possible to build on platforms without autoconf directly from a
	clean checkout of the repository. The configure script detects if
	the files are out of date when it also determines that the tools
	are present to regenerate them.

	* Add build in Azure Pipelines, now that it is free for open
	source projects.

2018-08-18  Jay Berkenbilt  <ejb@ql.org>

	* 8.2.1: release

	* Add new option --keep-files-open=[yn] to control whether qpdf
	keeps files open when merging. Prior to version 8.1.0, qpdf always
	kept all files open, but this meant that the number of files that
	could be merged was limited by the operating system's open file
	limit. Version 8.1.0 opened files as they were referenced, but
	this caused a major performance impact. Version 8.2.0 optimized
	the performance but did so in a way that, for local file systems,
	there was a small but unavoidable performance hit, but for
	networked file systems, the performance impact could be very high.
	Starting with version 8.2.1, the default behavior is that files
	are kept open if no more than 200 files are specified, but that
	the behavior can be explicitly overridden with the
	--keep-files-open flag. If you are merging more than 200 files but
	less than the operating system's max open files limit, you may
	want to use --keep-files-open=y. If you are using a local file
	system where the overhead is low and you might sometimes merge
	more than the OS limit's number of files, you may want to specify
	--keep-files-open=n. Fixes #237.

2018-08-16  Jay Berkenbilt  <ejb@ql.org>

	* 8.2.0: release

2018-08-14  Jay Berkenbilt  <ejb@ql.org>

	* For the mingw builds, change the name of the DLL import library
	from libqpdf.a to libqpdf.dll.a to avoid confusing it with a
	static library. This potentially clears the way for supporting a
	static library in the future, though presently, the qpdf Windows
	build only builds the DLL and executables. Fixes #225.

2018-08-13  Jay Berkenbilt  <ejb@ql.org>

	* Add new class QPDFSystemError, derived from std::runtime_error,
	which is now thrown by QUtil::throw_system_error. This enables the
	triggering errno value to be retrieved. Fixes #221.

2018-08-12  Jay Berkenbilt  <ejb@ql.org>

	* qpdf command line: add --no-warn option to suppress issuing
	warning messages. If there are any conditions that would have
	caused warnings to be issued, the exit status is still 3.

	* Rewrite the internals of Pl_Buffer to be much more efficient in
	use of memory at a very slight performance cost. The old
	implementation could cause memory usage to go out of control for
	files with large images compressed using the TIFF predictor.
	Fixes #228.

2018-08-05  Jay Berkenbilt  <ejb@ql.org>

	* Bug fix: end of line characters were not properly handled inside
	strings in some cases. Fixes #226.

	* Bug fix: infinite loop on progress reporting for very small
	files. Fixes #230.

2018-08-04  Jay Berkenbilt  <ejb@ql.org>

	* Performance fix: optimize page merging operation to avoid
	unnecessary open/close calls on files being merged. Fixes #217.

	* Add ClosedFileInputSource::stayOpen method, enabling a
	ClosedFileInputSource to stay open during manually indicated
	periods of high activity, thus reducing the overhead of frequent
	open/close operations.

2018-06-23  Jay Berkenbilt  <ejb@ql.org>

	* 8.1.0: release

2018-06-22  Jay Berkenbilt  <ejb@ql.org>

	* Bug fix: properly decrypt files with 40-bit keys that use
	revision 3 of the security handler. Prior to this, qpdf was
	reporting "invalid password" in this case. Fixes #212.

	* With --verbose, print information about each input file when
	merging files.

	* Add progress reporting to QPDFWriter. Programmatically, you can
	register a progress reporter with registerProgressReporter(). From
	the command line, passing --progress will give progress indicators
	in increments of no less than 1% as output files are written.
	Fixes #200.

	* Add new method QPDF::getObjectCount(). This gives an approximate
	(upper bound) account of objects in the QPDF object.

	* Don't leave files open when merging. This makes it possible
	merge more files at once than the operating system's open file
	limit. Fixes #154.

	* Add ClosedFileInputSource class, and input source that keeps its
	input file closed when not reading it. At the expense of some
	performance, this allows you to operate on many files without
	opening too many files at the operating system level.

	* Add new option --preserve-unreferenced-resources, which
	suppresses removal of unreferenced objects from page resource
	dictionaries during page splitting operations.

2018-06-21  Jay Berkenbilt  <ejb@ql.org>

	* Add method QPDFPageObjectHelper::removeUnreferencedResources and
	also QPDFPageDocumentHelper::removeUnreferencedResources that
	calls the former on every page. This method removes any XObject or
	Font references from the page's resource dictionary if they are
	not referenced anywhere in any of the content streams. This
	significantly reduces the size of split files whose pages
	internally share resource dictionaries. Fixes #203.

	* The --rotate option to qpdf no longer requires an explicit page
	range. You can now rotate all pages of a document with
	qpdf --rotate=angle in.pdf out.pdf. Fixes #211.

	* Create examples/pdf-set-form-values.cc to illustrate use of
	interactive form helpers.

	* Added methods QPDFAcroFormDocumentHelper::setNeedAppearances and
	added methods to QPDFFormFieldObjectHelper to set a field's value,
	optionally updating the document to indicate that appearance
	streams need to be regenerated.

	* Added QPDFObject::newUnicodeString and QPDFObject::unparseBinary
	to allow for more convenient creation of strings that are
	explicitly encoded in UTF-16 BE. This is useful for creating
	Unicode strings that appear outside of content streams, such as in
	page labels, outlines, form field values, etc.

2018-06-20  Jay Berkenbilt  <ejb@ql.org>

	* Added new classes QPDFAcroFormDocumentHelper,
	QPDFFormFieldObjectHelper, and QPDFAnnotationObjectHelper to
	assist with working with interactive forms in PDF files. At
	present, API methods for reading forms, form fields, and widget
	annotations have been added. It is likely that some additional
	methods for modifying forms will be added in the future. Note that
	qpdf remains a library whose function is primarily focused around
	document structure and metadata rather than content. As such, it
	is not expected that qpdf will have higher level APIs for
	generating form contents, but qpdf will hopefully gain the
	capability to deal with the bookkeeping aspects of wiring up all
	the objects, which could make it a useful library for other
	software that works with PDF interactive forms. PDF forms are
	complex, and the terminology around them is confusing. Please see
	comments at the top of QPDFAcroFormDocumentHelper.hh for
	additional discussion.

	* Added new classes QPDFPageDocumentHelper and QPDFPageObjectHelper
	for page-level API functions. These classes introduce a new API
	pattern of document helpers and object helpers in qpdf. The helper
	classes provide a higher level API for working with certain types
	of structural features of PDF while still staying true to qpdf's
	philosophy of not isolating the user from the underlying
	structure. Please see the chapter in the documentation entitled
	"Design and Library Notes" for additional discussion. The examples
	have also been updated to use QPDFPageDocumentHelper and
	QPDFPageObjectHelper when performing page-level operations.

2018-06-19  Jay Berkenbilt  <ejb@ql.org>

	* New QPDFObject::Rectangle class will convert to and from arrays
	of four numerical values. Rectangles are used in various places
	within the PDF file format and are called out as a specific data
	type in the PDF specification.

2018-05-12  Jay Berkenbilt  <ejb@ql.org>

	* In newline before endstream mode, an extra newline was not
	inserted prior to the endstream that ends object streams.
	Fixes #205.

2018-04-15  Jay Berkenbilt  <ejb@ql.org>

	* Arbitrarily limit the depth of data structures represented by
	direct object. This is CVE-2018-9918. Fixes #202.

2018-03-06  Jay Berkenbilt  <ejb@ql.org>

	* 8.0.2: release

	* Properly handle pages with no contents. Fixes #194.

2018-03-05  Jay Berkenbilt  <ejb@ql.org>

	* Improve handling of loops while following cross reference
	tables. Fixes #192.

2018-03-04  Jay Berkenbilt  <ejb@ql.org>

	* 8.0.1: release

	* On the command line when specifying page ranges, support
	preceding a page number by "r" to indicate that it should be
	counted from the end. For example, the range r3-r1 would indicate
	the last three pages of a document.

2018-03-03  Jay Berkenbilt  <ejb@ql.org>

	* Ignore zlib data check errors while uncompressing streams. This
	is consistent with behaviors of other readers and enables handling
	of some incorrectly written zlib streams. Fixes #191.

2018-02-25  Jay Berkenbilt  <ejb@ql.org>

	* 8.0.0: release

2018-02-17  Jay Berkenbilt  <ejb@ql.org>

	* Fix QPDFObjectHandle::getUTF8Val() to properly handle strings
	that are encoded with PDF Doc Encoding. Fixes #179.

	* Add qpdf_check_pdf to the "C" API. This method just attempts to
	read the entire file and produce no output, making possible to
	assess whether the file has any errors that qpdf can detect.

	* Major enhancements to handling of type errors within the qpdf
	library. This fix is intended to eliminate those annoying cases
	where qpdf would exit with a message like "operation for
	dictionary object attempted on object of wrong type" without
	providing any context. Now qpdf keeps enough context to be able to
	issue a proper warning and to handle such conditions in a sensible
	way. This should greatly increase the number of bad files that
	qpdf can recover, and it should make it much easier to figure out
	what's broken when a file contains errors.

	* Error message fix: replace "file position" with "offset" in
	error messages that report lexical or parsing errors. Sometimes
	it's an offset in an object stream or a content stream rather than
	a file position, so this makes the error message less confusing in
	those cases. It still requires some knowledge to find the exact
	position of the error, since when it's not a file offset, it's
	probably an offset into a stream after uncompressing it.

	* Error message fix: correct some cases in which the object that
	contained a lexical error was omitted from the error message.

	* Error message fix: improve file name in the error message when
	there is a parser error inside an object stream.

2018-02-11  Jay Berkenbilt  <ejb@ql.org>

	* Add QPDFObjectHandle::filterPageContents method to provide a
	different interface for applying token filters to page contents
	without modifying the ultimate output.

2018-02-04  Jay Berkenbilt  <ejb@ql.org>

        * Changes listed on today's date are numerous and reflect
	significant enhancements to qpdf's lexical layer. While many
	nuances are discussed and a handful of small bugs were fixed, it
	should be emphasized that none of these issues have any impact on
	any output or behavior of qpdf under "normal" operation. There are
	some changes that have an effect on content stream normalization
	as with qdf mode or on code that interacts with PDF files
	lexically using QPDFTokenizer. There are no incompatible changes
	for normal operation. There are a few changes that will affect the
	exact error messages issued on certain bad files, and there is a
	small non-compatible enhancement regarding the behavior of
	manually constructed QPDFTokenizer::Token objects. Users of the
	qpdf command line tool will see no changes other than the addition
	of a new command-line flag and possibly some improved error
	messages.

	* Significant lexer (tokenizer) enhancements. These are changes to
	the QPDFTokenizer class. These changes are of concern only to
	people who are operating with PDF files at the lexical layer using
	qpdf. They have little or no impact on most high-level interfaces
	or the command-line tool.

	New token types tt_space and tt_comment to recognize whitespace
	and comments. this makes it possible to tokenize a PDF file or
	stream and preserve everything about it.

	For backward compatibility, space and comment tokens are not
	returned by the tokenizer unless QPDFTokenizer.includeIgnorable()
	is called.

	Better handling of null bytes. These are now included in space
	tokens rather than being their own "tt_word" tokens. This should
	have no impact on any correct PDF file and has no impact on
	output, but it may change offsets in some error messages when
	trying to parse contents of bad files. Under default operation,
	qpdf does not attempt to parse content streams, so this change is
	mostly invisible.

	Bug fix to handling of bad tokens at ends of streams. Now, when
	allowEOF() has been called, these are treated as bad tokens
	(tt_bad or an exception, depending on invocation), and a
	separate tt_eof token is returned. Before the bad token
	contents were returned as the value of a tt_eof token. tt_eof
	tokens are always empty now.

	Fix a bug that would, on rare occasions, report the offset in an
	error message in the wrong space because of spaces or comments
	adjacent to a bad token.

	Clarify in comments exactly where the input source is positioned
	surrounding calls to readToken and getToken.

	* Add a new token type for inline images. This token type is only
	returned by QPDFTokenizer immediately following a call to
	expectInlineImage(). This change includes internal refactoring of
	a handful of places that all separately handled inline images, The
	logic of detecting inline images in content streams is now handled
	in one place in the code. Also we are more flexible about what
	characters may surround the EI operator that marks the end of an
	inline image.

	* New method QPDFObjectHandle::parsePageContents() to improve upon
	QPDFObjectHandle::parseContentStream(). The parseContentStream
	method used to operate on a single content stream, but was fixed
	to properly handle pages with contents split across multiple
	streams in an earlier release. The new method parsePageContents()
	can be called on the page object rather than the value of the
	page dictionary's /Contents key. This removes a few lines of
	boiler-plate code from any code that uses parseContentStream, and
	it also enables creation of more helpful error messages if
	problems are encountered as the error messages can include
	information about which page the streams come from.

	* Update content stream parsing example
	(examples/pdf-parse-content.cc) to use new
	QPDFObjectHandle::parsePageContents() method in favor of the older
	QPDFObjectHandle::parseContentStream() method.

	* Bug fix: change where the trailing newline is added to a stream
	in QDF mode when content normalization is enabled (the default for
	QDF mode). Before, the content normalizer ensured that the output
	ended with a trailing newline, but this had the undesired side
	effect of including the newline in the stream data for purposes of
	length computation. QPDFWriter already appends a newline without
	counting in length for better readability. Ordinarily this makes
	no difference, but in the rare case of a page's contents being
	split in the middle of a token, the old behavior could cause the
	extra newline to be interpreted as part of the token. This bug
	could only be triggered in qdf mode, which is a mode intended for
	manual inspection of PDF files' contents, so it is very unlikely
	to have caused any actual problems for people using qpdf for
	production use. Even if it did, it would be very unusual for a PDF
	file to actually be adversely affected by this issue.

	* Add support for coalescing a page's contents into a single
	stream if they are represented as an array of streams. This can be
	performed from the command line using the --coalesce-contents
	option. Coalescing content streams can simplify things for
	software that wants to operate on a page's content streams without
	having to handle weird edge cases like content streams split in
	the middle of tokens. Note that
	QPDFObjectHandle::parsePageContents and
	QPDFObjectHandle::parseContentStream already handled split content
	streams. This is mainly to set the stage for new methods of
	operating on page contents. The new method
	QPDFObjectHandle::pipeContentStreams will pipe all of a page's
	content streams though a single pipeline. The new method
	QPDFObjectHandle.coalesceContentStreams, when called on a page
	object, will do nothing if the page's contents are a single
	stream, but if they are an array of streams, it will replace the
	page's contents with a single stream whose contents are the
	concatenation of the original streams.

	* A few library routines throw exceptions if called on non-page
	objects. These constraints have been relaxed somewhat to make qpdf
	more tolerant of files whose page dictionaries are not properly
	marked as such. Mostly exceptions about page operations being
	called on non page objects will only be thrown in cases where the
	operation had no chance of succeeding anyway. This change has no
	impact on any default mode operations, but it could allow
	applications that use page-level APIs in QPDFObjectHandle to be
	more tolerant of certain types of damaged files.

	* Add QPDFObjectHandle::TokenFilter class and methods to use it to
	perform lexical filtering on content streams. You can call
	QPDFObjectHandle::addTokenFilter on stream object, or you can call
	the higher level QPDFObjectHandle::addContentTokenFilter on a page
	object to cause the stream's contents to passed through a token
	filter while being retrieved by QPDFWriter or any other consumer.
	For details on using TokenFilter, please see comments in
	QPDFObjectHandle.hh.

	* Enhance the string, type QPDFTokenizer::Token constructor to
	initialize a raw value in addition to a value. Tokens have a
	value, which is a canonical representation, and a raw value. For
	all tokens except strings and names, the raw value and the value
	are the same. For strings, the value excludes the outer delimiters
	and has non-printing characters normalized. For names, the value
	resolves non-printing characters. In order to better facilitate
	token filters that mostly preserve contents and to enable
	developers to be mostly unconcerned about the nuances of token
	values and raw values, creating string and name tokens now
	properly handles this subtlety of values and raw values. When
	constructing string tokens, take care to avoid passing in the
	outer delimiters. This has always been the case, but it is now
	clarified in comments in QPDFObjectHandle.hh::TokenFilter. This
	has no impact on any existing code unless there's some code
	somewhere that was relying on Token::getRawValue() returning an
	empty string for a manually constructed token. The token class's
	operator== method still only looks at type and value, not raw
	value. For example, string tokens for <41> and (A) would still be
	equal because both are representations of the string "A".

	* Add QPDFObjectHandle::isDataModified method. This method just
	returns true if addTokenFilter has been called on the stream. It
	enables a caller to determine whether it is safe to optimize away
	piping of stream data in cases where the input and output are
	expected to be the same. QPDFWriter uses this internally to skip
	the optimization of not re-compressing already compressed streams
	if addTokenFilter has been called. Most developers will not have
	to worry about this as it is used internally in the library in the
	places that need it. If you are manually retrieving stream data
	with QPDFObjectHandle::getStreamData or
	QPDFObjectHandle::pipeStreamData, you don't need to worry about
	this at all.

	* Provide heavily annotated examples/pdf-filter-tokens.cc example
	that illustrates use of some simple token filters.

	* When normalizing content streams, as in qdf mode, issue warning
	about bad tokens. Content streams are only normalized when this is
	explicitly requested, so this has no impact on normal operation.
	However, in qdf mode, if qpdf detects a bad token, it means that
	either there's a bug in qpdf's lexer, that the file is damaged, or
	that the page's contents are split in a weird way. In any of those
	cases, qpdf could potentially damage the stream's contents by
	replacing carriage returns with newlines or otherwise messing with
	spaces. The mostly likely case of this would be an inline image's
	compressed data being divided across two streams and having the
	compressed data in the second stream contain a carriage return as
	part of its binary data. If you are using qdf mode just to look at
	PDF files in text editors, this usually doesn't matter. In cases
	of contents split across multiple streams, coalescing streams
	would eliminate the problem, so the warning mentions this. Prior
	to this enhancement, the chances of qdf mode writing incorrect
	data were already very low. This change should make it nearly
	impossible for qdf mode to unknowingly write invalid data.

2018-02-04  Jay Berkenbilt  <ejb@ql.org>

	* Add QPDFWriter::setLinearizationPass1Filename method and
	--linearize-pass1 command line option to allow specification of a
	file into which QPDFWriter will write its intermediate
	linearization pass 1 file. This is useful only for debugging qpdf.
	qpdf creates linearized files by computing the output in two
	passes. Ordinarily the first pass is discarded and not written
	anywhere. This option allows it to be inspected.

2018-02-04  Jay Berkenbilt  <ejb@ql.org>

	* 7.1.1: release

	* Bug fix: properly linearize files whose /ID has a length of
	other than 16 bytes.

	* Rename some test files to avoid files with three dots in their
	names. Fixes #173.

	* Fix various build and compilation issues on some platforms and
	compilers. Fixes #176, #172, #177

	* Fix a few typos and clarify a few comments in header files.

2018-01-14  Jay Berkenbilt  <ejb@ql.org>

	* 7.1.0: release

	* Allow raw encryption key to be specified in library and command
	line with the QPDF::setPasswordIsHexKey method and
	--password-is-hex-key option. Allow encryption key to be displayed
	with --show-encryption-key option. Thanks to Didier Stevens
	<didier.stevens@gmail.com> for the idea and contribution of one
	implementation of this idea. See his blog post at
	https://blog.didierstevens.com/2017/12/28/cracking-encrypted-pdfs-part-3/
	for a discussion of using this for cracking encrypted PDFs. I hope
	that a future release of qpdf will include some additional
	recovery options that may also make use of this capability.

2018-01-13  Jay Berkenbilt  <ejb@ql.org>

	* Fix lexical error: the PDF specification allows floating point
	numbers to end with ".". Fixes #165.

	* Fix link order in the build to avoid conflicts when building
	from source while an older version of qpdf is installed. Fixes #158.

	* Add support for TIFF predictor for LZW and Flate streams. Now
	all predictor functions are supported. Fixes #171.

2017-12-25  Jay Berkenbilt  <ejb@ql.org>

	* Clarify documentation around options that control parsing but
	not output creation. Two options: --suppress-recovery and
	--ignore-xref-streams, were documented in the "Advanced
	Transformation Options" section of the manual and --help output
	even though they are not related to output. These are now
	described in a separate section called "Advanced Parsing Options."

	* Implement remaining PNG filters for decode. Prior versions could
	decode only the "up" filter. Now all PNG filters (sub, up,
	average, Paeth, optimal) are supported for decoding. Thanks to
	Tobias Hoffmann for providing a test PDF file that has images with
	all PNG filters along with different numbers of bits per sample
	and samples per pixel, and thanks to Casey Rojas for providing
	implementations of the remaining PNG filters.

	The implementation of the remaining PNG filters changed the
	interface to the private Pl_PNGFilter class, but this class's
	header file is not in the installation, and there is no public
	interface to the class. Within the library, the class is never
	allocated on the stack; it is only ever dynamically allocated. As
	such, this does not actually break binary compatibility of the
	library.

2017-09-15  Jay Berkenbilt  <ejb@ql.org>

	* 7.0.0: release

2017-09-12  Jay Berkenbilt  <ejb@ql.org>

	* Relicense qpdf under version 2.0 of the Apache License rather
	than version 2.0 of the Artistic License. Both are fine, but the
	Apache License is in more widespread use, and I like it a little
	better than Artistic-2.0. It is my intention that there be no
	change in what you can or can't do with qpdf. Versions of qpdf
	prior to version 7 were released under the terms of version 2.0 of
	the Artistic License. At your option, you may continue to consider
	qpdf to be licensed under those terms. Please see the manual for
	additional information.

	* Improve the error message that is issued when QPDFWriter
	encounters a stream that can't be decoded. In particular, mention
	that the stream will be copied without filtering to avoid data
	loss.

	* Add new methods to the C API to correspond to new additions to
	QPDFWriter:
	- qpdf_set_compress_streams
	- qpdf_set_decode_level
	- qpdf_set_preserve_unreferenced_objects
	- qpdf_set_newline_before_endstream

2017-08-25  Jay Berkenbilt  <ejb@ql.org>

	* Re-implement parser iteratively to avoid stack overflow on very
	deeply nested arrays and dictionaries. Fixes #146.

	* Detect infinite loop while finding additional xref tables. Fixes
	#149.

2017-08-22  Jay Berkenbilt  <ejb@ql.org>

	* 7.0.b1: release

	* Convert all README files to markdown. Names changed as follows:
	  - README --> README.md
	  - README.hardening --> README-hardening.md
	  - README.maintainer --> README-maintainer.md
	  - README-what-to-download.txt --> README-what-to-download.md
	  - README-windows.txt --> README-windows.md
	  The file README-windows-install.txt remains a text file.

2017-08-21  Jay Berkenbilt  <ejb@ql.org>

	* Add support for writing PCLm files. Most of the work was done by
	Sahil Arora <sahilarora.535@gmail.com> as part of a Google Summer
	of Code project in 2017. PCLm support is useful only for clients
	that specifically know how to create PCLm files. Support in qpdf
	is just for ensuring that objects are written in the correct order
	and for including some additional material in the output that is
	required by the PCLm standard.

2017-08-19  Jay Berkenbilt  <ejb@ql.org>

	* Remove --precheck-streams. This is enabled by default now
	without any efficiency cost. This feature was never released.

	* Update pdf-create example to illustrate use of additional image
	compression filters.

	* Add support for /RunLengthDecode and /DCTDecode:
	  - New pipeline types Pl_RunLength and Pl_DCT
	  - New command-line flags --compress-streams and --decode-level
	    to replace/enhance --stream-data
	  - New QPDFWriter::setCompressStreams and
 	    QPDFWriter::setDecodeLevel methods
	  Please see documentation, header files, and help messages for
	  details on these new features.

2017-08-12  Jay Berkenbilt  <ejb@ql.org>

	* Add QPDFObjectHandle::rotatePage to apply rotation to a page
	object. Add --rotate option to qpdf to specify page rotation from
	the command line.

	* Provide --verbose option that causes qpdf to print an indication
	of what files it is writing.

	* Change --single-pages to --split-pages and make it take an
	optional argument specifying the number of pages per file.

2017-08-11  Jay Berkenbilt  <ejb@ql.org>

	* Fix --newline-before-endstream to always add a newline before
	endstream even if the last character was already a newline. This
	is actually what's required by PDF/A. Fixes #133.

	* Handle encrypted files whose encryption parameters are too
	short. Fixes #96.

2017-08-10  Jay Berkenbilt  <ejb@ql.org>

	* Remove dependency on libpcre.

	* Be more forgiving of certain types of errors in the xref table
	that don't interfere with interpreting the table.

	* Remove unused "tracing" parameter from PointerHolder's
	(T*, bool) constructor. This change breaks source code
	compatibility, but since this argument to PointerHolder has not
	used for a long time and the presence of a boolean parameter in
	the primary constructor makes it too easy to use that by mistake
	when trying to use PointerHolder for arrays, it seems like it's
	finally time to take it out. If you have a compile error because
	of this change, please check to see whether you intended to use
	the (bool, T*) version of the constructor instead. If not, just
	remove the second parameter.

2017-08-09  Jay Berkenbilt  <ejb@ql.org>

	* When recovering stream length, find endobj without endstream as
	well as just looking for endstream. Be a little more lax about
	where we allow it to be found.

2017-08-05  Jay Berkenbilt  <ejb@ql.org>

	* Add --single-pages option to cause output to be written to a
	separate file for each page rather than one big file.

	* Process --pages options earlier so that certain inspection
	options, like --show-pages, can show the state after the merging
	operations.

2017-08-02  Jay Berkenbilt  <ejb@ql.org>

	* Fix off-by-one error in parsing pages options. Fixes #129.

2017-07-29  Jay Berkenbilt  <ejb@ql.org>

	* Support @filename and @- in the qpdf command-line tool to read
	command-line arguments, one per line, from the named file. @-
	reads from standard input. Fixes #16.

	* Detect when input file and output file are the same and exit to
	avoid overwriting and losing input file. Fixes #29.

	* When passing multiple inspection arguments, run --check first,
	and defer exit until after all the checks have been run. This
	makes it possible to force operations such as --show-xref to be
	delayed until after recovery attempts have been made. For example,
	if you have a file with a syntactically valid xref table that has
	some offsets that are incorrect, running qpdf --check --show-xref
	on that file will first recover the xref and the dump the
	recovered xref, while just running qpdf --show-xref will show the
	xref table as present in the file. Fixes #42.

	* When recovering stream length, indicate the recovered length.
	Fixes #44.

	* Add --newline-before-endstream command-line option and
	setNewlineBeforeEndstream method to QPDFWriter. This forces qpdf
	to always add a newline before the endstream keyword. It is a
	necessary but not sufficient condition for PDF/A compliance. Fixes
	#103.

	* Handle zlib data errors when decoding streams. Fixes #106.

	* Improve handling of files where the "stream" keyword is not
	followed by proper line terminators. Fixes #104.

	* Fix content stream parsing to handle cases of structures within
	the stream split across stream boundaries. Fixes #73.

2017-07-28  Jay Berkenbilt  <ejb@ql.org>

	* Add --preserve-unreferenced command-line option and
	setPreserveUnreferencedObjects method to QPDFWriter. This option
	causes QPDFWriter to write all objects from the input file to the
	output file regardless of whether the objects are referenced.
	Objects are written to the output file in numerical order from the
	input file. This option has no effect for linearized files.

2017-07-27  Jay Berkenbilt  <ejb@ql.org>

	* Add --precheck-streams command-line option and setStreamPrecheck
	method to QPDFWriter to tell QPDFWriter to attempt decoding a
	stream fully before deciding whether to filter it or not.

	* Recover gracefully from streams that aren't filterable because
	the filter parameters are invalid in the stream dictionary or the
	dictionary itself is invalid.

	* Significantly improve recoverability from invalid qpdf objects.
	Most conditions in basic object parsing that used to cause qpdf to
	exit are now warnings. There are still many more opportunities for
	improvements of this sort beyond just object parsing.

2017-07-26  Jay Berkenbilt  <ejb@ql.org>

	* Fixes to infinite loops below also fix problems reported in
	other issues and cover CVE-2017-11624, CVE-2017-11625,
	CVE-2017-11626, and CVE-2017-11627.

	* Don't attempt to interpret syntactic keywords (like R and
	endobj) found while parsing content streams.

	* Detect infinite loops while resolving objects. This could happen
	if something inside an object that had to be resolved during
	parsing, such as a stream length, recursively referenced the
	object being resolved.

	* CVE-2017-9208: Handle references to and appearance of object 0
	as a special case. Object 0 is not allowed, and qpdf was using it
	internally to represent direct objects.

	* CVE-2017-9209: Fix infinite loop caused by attempting to
	reconstruct the xref table while already in the process of
	reconstructing the xref table.

	* CVE-2017-9210: Fix infinite loop caused by attempting to unparse
	an object for inclusion in the text of an exception.

2015-11-10  Jay Berkenbilt  <ejb@ql.org>

	* 6.0.0: release

	* No changes from 5.2.0. The 5.2.0 release broke binary
	compatibility and was withdrawn.

2015-10-31  Jay Berkenbilt  <ejb@ql.org>

	* 5.2.0: release

	* libqpdf/QPDF.cc (read_xrefTable): Be tolerant of some malformed
	xref tables that don't have the required trailing space after each
	line.

2015-10-29  Jay Berkenbilt  <ejb@ql.org>

	* Implement QPDFWriter::setDeterministicID and --deterministic-id
	commandline-flag to qpdf to request generation of a deterministic
	/ID for non-encrypted files.

2015-05-24  Jay Berkenbilt  <ejb@ql.org>

	* 5.1.3: release

	* Bug fix: fix-qdf was not handling object streams with more than
	255 objects in them.

	* Handle Microsoft crypt provider initialization properly for case
	where no keys have been previously created, such as in a fresh
	Windows installation.

	* Include time.h in QUtil.hh for time_t

2015-02-21  Jay Berkenbilt  <ejb@ql.org>

	* Detect loops in Pages structure. Thanks to Gynvael Coldwind and
	Mateusz Jurczyk of the Google Security Team for providing a sample
	file with this problem.

	* Prevent buffer overrun when converting a password to an
	encryption key. Thanks to Gynvael Coldwind and Mateusz Jurczyk of
	the Google Security Team for providing a sample file with this
	problem.
