Port the Qt5 viewer demo to use the lazy outline item API (even if for loading all items up front for now).

Remove the intermediate Outline type since all items are owned by the document and the top-level items will always be eagerly loaded anyway.

Add poppler_document_get_print_scaling() function and
PopplerPrintScaling enum so that applications which
use poppler's glib frontend can access this preference.

https://bugs.freedesktop.org/show_bug.cgi?id=92779

Named destinations may be described by bytestrings, containing
embedded NULs and not being NUL terminated. That means they cannot
be exposed directly as char*.

The alternatives are to escape the string from the internal representation
when exposing it in the API (e.g. in PopplerDest.named_dest), or to
add parallel API exposing it as GString, or GBytes. This patch chooses
the first option, since the presence of these named destionations in the
public, not sealed, PopplerDest struct means that the second option would
need more API additions. The chosen option is simpler, and does not
need the API users to adapt unless they create the named dest strings
themselves, or consume them in ways other than calling poppler APIs.

The escaping scheme chosen simply replaces embedded NUL with "\0" and
escapes a literal backslash with "\\".  This is a minimal ABI change in
that some strings that previously worked unchanged as destinations
(those containing backslash) now don't work, but on the other hand,
previously it was impossible to use any destinations containing embedded
NULs.

Add poppler_named_dest_{from,to}_bytestring() to perform that
conversion, and clarify the documentation for when you need them.

Based on a patch by José Aliste <jaliste@src.gnome.org>.

#631

This is BC because the version with it was never released

People will shoot themselves on the foot and we don't need it

the left hand is a std::string

The openFileDescriptor function is not user in the WIN32 codepaths,
so just #ifdef it out on WIN32.

First try to atomically open the file using O_CLOEXEC for open()
and the "e" mode for fopen(), and if that doesn't work or O_CLOEXEC
isn't defined, fall back to opening the file first and applying
the FD_CLOEXEC flag afterwards.

This is in preparation to making the wrapper enforce the O_CLOEXEC flag.

Use the openFile wrapper instead of calling fopen directly
in the libraries.

It was causing regressions for some half-broken files

Rationale:

Even if xref::constructXRef is returning false, that only means "i
din't find a new xref root", but constructXRef is also quite stubborn in
which it basically parses the whole file and stores the positions of all
the objects it finds, so for some half broken pdf files this is good
enough and we will be able to render those files just fine

At that point xref can have gone wrong since extractPDFSubtype() can
have caused a reconstruct that broke stuff so instead of unconditionally
returning true, return xref->isOk()

Fixes #706

SplashXPathScanner is only used inside the each fill function, but newer
passed to the outside. As it is small, there is no reason to not
allocate it on the stack.

Again no (C)

No (C) for this (a machine could do it)

Avoid global display profile state becoming an uncontrolled memory leak by enforcing single initialization. Closes #654

Do not try to parse into unallocated XRef entry and return pointer to dummy entry instead. Closes #692 and oss-fuzz/12330

Fixes #704

fixes oss-fuzz/12243