Starting at 61b2bd5e, boost::bind was progressively replaced with
std::bind. They are not interchangeable though. boost::bind implements
the tracking of boost::signals{,2}::trackable objects. Now that
std::bind has completely replaced boost::bind, tracking never occurred.
This commit replaces boost::signals2::trackable with the new preferred
boost::signals2 methods: scoped_connections or slot::track_foreign. The
support::Trackable class introduced is less safe but easier for transitioning
old code.
Fixes the crash at #8261.
This reverts commit d568846e03.
Unfortunately the used alternative API LSCopyDefaultApplicationURLForContentType
is available with 10.10 and later only and cannot be used therefore. So there
is no alternative to deprecated calls ATM. LyX 2.3 should run on 10.7 at least.
Seemingly, when removing an argument from argv, and thus inserting
a null pointer to shorten the array, causes an assertion because
the null pointer is not a valid heap pointer (sic!)
Fixes bug #10440
There a some exceptions related to the fact that BOOST_ASSERT throws
an unhandled exception, which is fait enough. This is handled by
uploading a modeling file to coverity.
The second batch of issues are related to the use of lexical_cast in
convert.cpp. We use now a wrapper around boost::lexical_cast that does
not throw but return empty strings instead. I am not sure actually of
when lexical_cast could fail.
The added cmake-parameter is:
-DLYX_EXTERNAL_MYTHES=<value>
where <value> is one of
AUTO (Default) Search first on system for mythes (lib and include)
ON Use installed only (errors if not installed)
OFF Compile the provided source in 3rdparty
Useful to cache copies of objects, including shared_ptrs. No risks of dangling
pointer, and avoid naked pointers in the source.
Fix memory leak when compiling with Qt5.
For biblatex, we need the file name as it was entered in the inset
(abs path, rel path, only file name) in order to resolve it properly
for the export (as in the BibTeX inset intself).
Therefore, we now store a pair<docstring, FileName>.
A FileNamePairList has been added to FileNameList for this purpose.
Fixes: #8831
This introduces
* a new inset member isPartOfTextSequence() that returns
whether the inset produces something visible at the current position
in the text flow
* an isOpenPunctuation() test that returns whether a character is in the
'Punctuation, Open' unicode class. This is used instead of just checking
for two (Western, ASCII) opening brackets
It also fixes the isChar() and isLetter() value of InsetSpecialChar,
since some types have not been assigned correctly.
The QTextLayout handling is terribly slow on Qt 4.8.7, but some
caching has been added in Qt5 that makes it much faster. For some
reason, it is not that slow with Qt 4.8.1.
Caches are introduced for the three following methods
* width(doctring), controlled by CACHE_METRICS_WIDTH. This cache already
existed, but the code has been cleaned up
* getTextLayout, controlled by CACHE_METRICS_QTEXTLAYOUT (disabled by
default on Qt5, which does its own caching). This is used for pos2x
and x2pos and now for drawing of text too. The previous code used a
trivial caching scheme of the last used QTextLayout, but now they
are properly kept in a QCache. Moreover, the cacheEnabled() property
is enabled for these QTextLayout object (not sure what this does).
* breakAt, controlled by CACHE_METRICS_BREAKAT. This is the only user
of QTextLayout which did not have some kind of caching already.
For some weird reasons related to Argument-dependent look-up, the
qHash(docstring) function has to be defined in std namespace, since
lyx::docstring is actually std::basic_string<wchar_t>.
[NOTE: this version has profiling hooks, enabled by commenting out the line
#define DISABLE_PMPROF
that should eventually be removed.]
In fact having an extra parameter "bool cond" is no longer useful because it can
now always be emulated with a ternary operator:
Changers dummy = cond ? do_change() : Changer();
A static local variable is guaranteed to be initialized only once, and in time.
Lambda expressions can be used to perform complex initialization of those static
variables on the spot.
(starting from: gcc >= 4.8, msvc >= 2015)
The function is no longer used in LyX's sources (as of the previous
comit, 9b64d7bd) and is thus removed with this commit. Perhaps the
advantage this function had over other path functions we have has
disappeared over time (see e.g. 1a7b7f65).
The only exceptions are:
- The purpose of the header is to drag in the used symbol, e.g. unique_ptr.h
- The used symbol is inside a class or a namespace other than lyx
The reason for this is that global 'using' statements effectively forbid to
use the used symbols in any other namespace in the whole program, since simply
adding or removing an #include of the corresponding header subtly changes the
name lookup. The namespace lyx is sort of global, so it should not have these
statements either.
RefChanger temporarily assigns a value to a non-const reference of any
kind. RefChanger provides a flexible and uniform generalisation of the various
scope guards previously derived from the old Changer class in MetricsInfo.h.
As before, a temporary assignment lasts as long as the Changer object lives. But
the new Changer is movable. In particular, contorsions are no longer needed to
change a private field. Special code can be moved into the appropriate classes,
and it is no longer necessary to create a new class for each specific use.
Syntax change:
FontSetChanger dummy(mi.base, value);
-> Changer dummy = mi.base.changeFontSet(value);
New function for generating arbitrary Changers:
Changer dummy = make_change(ref, val, condition);
Bugfix:
* Fix the display of \displaystyle{\substack{\frac{xyz}{}}} (missing style
change).
Boost.Signals is deprecated. This fixes bug #9943.
The only thing left to do is to rewrite (or get rid of) the boost -mt test
in config/lyxinclude.m4 not to use signals anymore.
It is no longer needed to create fake copy constructors and assignment and to
deal with deletion by hand, thanks to unique_ptr, the inference of move
constructor and assignment operator, and the compatibility of standard
containers with movable objects.
Two better ways of making a class non-copyable in C++11:
* Store the p. impl. in a unique_ptr (for the cases of classes with p. impl.),
or:
* Define publicly the copy constructor and assignment as deleted
Lots of other classes could be cleaned up in this way.
As discussed on the list. If no C++11 compiler is found configuration stops
with an error. There are now unneeded parts of boost, the will be removed in
a second commit.
It turns out that it did not take off since introduced in 2011. It is better to remove it and the associated boost headers (extract.sh was run against boost 1.60 to do the update).
Since we will move away from several boost classes when transitioning to C++11, it is good to start by removing lesser used ones.
It is easier to use instead getVectorFromString for the use we have of this tokenizer. The two places are environment.cpp (path stuff) and qt_helpers (file fileters). The new code is much shorter.
This allow to remove boost/tokenizer.hpp and friends from our boost tree.
Compiling different parts of the sources with different WINVER may lead to
subtle and hard to detect problems. Better use the same value everywhere.
The existing error message suggests that this was wanted anyway, and it
fixes a compiler warning when cross-compiling for mingw on linux. Our code
does not require a specific value, only a minimum value of 0x5000, which
means the resulting executable will require at least Windows 2000.
The included iconv should not be used on Linux or OS X, but (depending on
local configuration) it might be needed for crosscompiling a mingw target
from Linux. Now the user can choose whether to use the included iconv or not.
cmake does already support that.
eilseq.m4 was taken from the original libiconv 1.14 package.
On mingw-w64, long long (64bit wide) is larger than long (32bit wide).
Therefore we need some more specializations for string, docstring,
otextstream and << overloaded ostream functions. The configuration code
is by me, the source code changes by Shankar Giri Venkita Giri (bug 10053).
This is needed for warning-free compilation with mingw-w64, and does not hurt
for other build configurations. Patch by Shankar Giri Venkita Giri (bug 10053).
This fixes a failing unit test with 32bit gcc 4.9.3 and -O2 optimization:
It computed 9953 instead of 9954 for Length::inPixels() of value 2342.
The reason for this is probably different rounding behaviour caused by storing
the unrounded value in a processor register (uses 80bit accuracy) vs. writing
it back to memory (uses 64bit accuracy). The unrounded value is very close to
9953.5 (which is not representable as an exact IEEE floating point value).
Apart from that, having a proper function for rounding makes the code more
readable, and has the nice side effect to make Length::inPB() work for
negative lengths as well.
We open the input file now twice: The first time in latin1 encoding to read
the document encoding from the preamble. This does always work, since
traditional TeX does not allow non-ASCII contents without an encoding changing
command (except for comments, but we do not need them, and using latin1 rather
than utf8 ensures that they do not produce an iconv exception, but are simply
recored with wrong characters), and we do detect the utf8 based TeX engines
XeTeX and LuaTeX as well. The second time we open the file directly with the
document encoding.
This fixes a few tex2lyx tests on OS X, since changing the encoding of an
open file steam does not work with clang on OS X. Files using more than one
encoding are still broken, but all single-encoding files are fixed now.
Changing the codecvt_facet of a file stream after the file has been opened
does not work with clang on OS X. Therefore we avoid it if possible (i. e. the
new encoding is the same as the old one).
External processes cannot access files which are open in LyX. Therefore the
temp files created by the external inset need to be closed right after
creation. The symptom was that the date inset did not produce any outout on
windows (bug 9925). This change reverts a small part of f09a9fe2.
Although the date inset is unimportant and will probably be removed, this
change is important for all external insets that make use of temp files.
boost::regex supports escape sequences starting with a backslash in format
strings of regex_replace, but std::regex does not. Therefore format strings
involving literal backslashes have to be written differently for both flavours.
The special MSVC handling in regex.h is removed, since it is not needed
anymore, and using grep syntax would definitely be wrong.
The changed code is not used, but I tried to use a similar approach for
boost::regex, and found some problems:
- regex_replace and regex_search are implemented in the replacement, so they
must not be used directly
- an smatch object must be given by reference (as in the called methods),
otherwise an exception would be thrown at runtime
- the commented out regex_replace version is actually needed
This code is supposed to be deleted, but nevertheless I wanted to record here
how it had to be modified if it was actually needed.
Other than BIBINPUTS, also BSTINPUTS and TEXFONTS are exported.
They do not replicate the setting for TEXINPUTS but are set such
that the current dir (i.e., the temp dir) and the document dir
are also searched for bibtex and fonts related files.
Remove member disp_ that is defined both in Cursor and CursorData classes
Pass parameter of convert<T>(docstring const) templates as const reference for performance.
This was made visible by aab1b145a5, since xhtml export for
lib/doc/Additional.lyx caused an exception. However, the cause for this was
already present earlier: All attempts to output a std::string to an
odocstream resulted in trying to change the encoding of the stream instead,
since there is no operator<<(odocstream &, std::string) defined, and an
implicit conversion to SetEnc happened instead.
This is fixed by making the SetEnc constructor explicit and adjusting all
code parts that did not compile anymore after that. The parts of the code
that did use the wrong output operator were the std::string version of
htmlize() from output_xhtml.cpp and all changed parts in the other .cpp files.
I also removed the std::string versions of html::htmlize() and
html::cleanAttr(), since it was difficult to see which encodings were used
with these. Now we are always explcit when using html::cleanAttr() and
html::htmlize().
These were found by cppcheck:
Member variable 'x' is not initialized in the constructor.
The crash #9788 would not have happened if this had been done earlier.
Use the function support:truncateWithEllipsis() to shorten a docstring with
... at the end. Actually we use U+2026 HORIZONTAL ELLIPSIS instead of "..." when
automatically shortening strings. This is to be consistent with Qt's own
truncation and is much nicer on the screen.
This includes the bugs #9575 and #9572 regarding broken text elision in the
outliner.
Known issues (non-regressions):
* TocBackend::updateItem() should be rewritten to update all TOCs. (#8386)
* "..." should be replaced with … everywhere else on the interface (including
translation strings).
* We should prefer to rely on QFontMetrics::elidedText() to truncate strings
with an ellipsis whenever possible, or an equivalent for the buffer view
dependent on the font metrics. See the warning in src/support/lstrings.h.
These were all flagged by "(style) The scope of the variable 'x' can be reduced."
Narowing the scope improves readability, and if it is in a loop then the
compiler will be clever enough to produce efficient code, we do not need
manual optimization for POD types.
These were all found by cppcheck. Even in constructors that are there "only
because of std containers" the class should be initialized correctly. You can
never know whether such an object does not get used, and then a nice crash
caused by dereferencing a NULL-pointer is better than undefined behaviour.
The 'using namespace std' at the top of the file makes it quite difficult to
understand which abs is used: double std::abs<double>(double) or
int ::abs(int)? Now it is explicit, and the code does not change in subtle
ways if somebody removes the using statement.
This replaces tests for __cplusplus >= 201103L, which are wrong with gcc 4.6 and earlier. Indeed these versions of gcc define __cplusplus = 1.
Reference:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=1773
Newer boost versions use complicated type traits for boost::next and
boost::prior, which do not work with the RandomAccessList iterators.
The long term solution is to use std::next and std::prev, for now supply
simple replacements for compilers that do not support C++11 yet.
This fixes hopefully the compilation of check_trivstring on cygwin and
solaris. Previously I did not use the explicit instantiation, because c_str()
is used by other explicitly instantiated methiods, but for some reason this
does not seem to suffice.
LaTeX lengths must not use scientific notation, since the + sign has a
different meaning (glue lengths). This is the export part of bug 9416, the GUI
part is still not fixed.
The "save-as" part of the bug is fixed by extending the \textclass tag
such that, if a local layout file is used, its path relative to the
document directory is now stored together with the name. If a relative
path cannot be used, an absolute one is used but, in this case, the
document is not usable on a different platform.
The "copy" part is fixed by introducing a new \origin tag, which is
written when the file is saved. This tag stores the absolute path of
the document directory. If the document is manually copied to a
different location, the local layout file is retrivied by using
\origin (which is only updated on save).
This new tag may prove useful also for locating other files when the
document is manually moved to a different directory.
As in the original implementation the files needed for the layout
(for example, a latex class) had to be in the same directory as the
layout file, this directory has also to be added to TEXINPUTS.
We claim that gcc 4.x is needed in INSTALL, so it does not make sense to keep
this old stuff. Instead, I made configure output an error if gcc is too old.
The GNU libstdc++ that ships witch gcc 5 can be used with the same ABI as
older versions, or with a new ABI which is conformant to the C++11 standard.
LyX did not build if the latter was used:
https://kojipkgs.fedoraproject.org//work/tasks/1267/9651267/build.log
This is now fixed by detecting the ABI version and disabling the wrong forward
declarations. At the same time, STD_STRING_USES_COW is switched off for the
C++11 ABI version, because the std::basic_string implementation is now C++11
conformant. Since the GNU libstdc++ can also used by other compilers such as
clang, we must not test for the compiler version.
This fixes a situation where LyX did not detect that something went
wrong (that an external comman crashed) and reported that export was
successful. To reproduce, use the following version of LuaTeX (the
bug in LuaTeX causing the crash has since been fixed):
LuaTeX, Version beta-0.79.1 (TeX Live 2014) (rev 4971)
Then open FeynmanDiagrams.lyx and export with PDF (LuaTeX).
In the documentation [1] for QProcess::exitCode() it states:
"This value is not valid unless exitStatus() returns NormalExit."
For more information, see:
https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg185317.html
[1] http://doc.qt.io/qt-5/qprocess.html#exitCode
I am moving the corresponding code directly to InsetInfo.cpp.
Moreover, the size of the image displayed by the info inset is
now dynamically set according to the text size.
It is better to introduce a dummy blank dir in TEXINPUTS rather than
appending a blank at the end. Even if I have checked that this is not
a problem with MikTeX, some other engine (maybe texlive, but I cannot
check) could not ignore this space and take it as the name of a dir.
In this case, TEXINPUTS would not end with an empty element and the
standard search path would not be inserted there.
If a compressed svg icon is present, load it instead of a png one.
Also introduce two more sizes (huge and giant icons) that should be
useful when using hires displays, as svg icons automatically scale
to the desired size without loss of quality.
This is needed since src/support calls lots of qt code, and some parts of it
(e.g. QFileInfo) require a running event loop. This fixes bug #4917 which is
a symptom of the problem.
The fix is to create a QCoreApplication for tex2lyx, lyxclient and LyX running
without GUI. In the future this could be extended, i.e. to split up the
frontend Application class in a GUI and a console class, and having the
console class use LyXConsoleApp in the same way as Application now uses
GuiApplication. If that is done, one could also think of moving
support/ConsoleApplication to frontend/console/ConsoleApplication.
This resolves a dependency of src/support/docstream.cpp on src/TexRow.cpp,
which is the wrong way round. This fixes the linking
src/tests/check_ExternalTransforms with MSVC where the linker is not clever
enough to detect that the whole otexstream class is unused.
It works with gcc >= 4.9.0 and clang (with libc++ or gcc libstdc++ from gcc
>= 4.9.0). The MSVC parg is missing, because I cannot test it, and the
autotools build still link against boost::regex even if it is not needed, but
I don't know how to fix that.
As discussed on the list. We don't need it anymore, either we have a modern
compiler that supports C++11, or we fall back to boost. I kept and adjusted
the regex #define, since we cannot use std regex completely yet.
This is needed since all formats are stored in a global list which is shared
between threads, but never modfified except from the main thread.
The only missing bit is extension_list_, which is not so easy to do.
If we compile in C++11 mode, do not use the boost replacements for bind,
functional and shared_ptr. regex is excluded, since it misses match_partial, and
gcc does not provide a usable one in versions less than 4.9.0.
I also removed the #define for match_partial, since this is dangerous. Now you
get a compile error instead of subtle runtime differences.
The old detection did only work if CFLAGS contained -std=c++11, since ciso646
was only included for __cplusplus > 199711.
Thanks to Koernel for the cmake part.
The interface is now 100% unit tested, and the typedefs depend on the new
STD_STRING_USES_COW configuration variable. The only missing bit is to detect
clang and disable STD_STRING_USES_COW for clang.
As discused on the list. This is not used yet, but it is intended to provide
thread-safe read-access without the need for synchronization if the used STL
implementation does not provide it for std::basic_string. This is the case for
all implementations using copy-on-write.
docstring is already defined in strfwd.h (which is included from docstring.h).
There are only two possible cases:
Either the typedef in docstring.h defines an identical type (then it is not
needed), or it defines a different type (then it generates a compilation error)
=> it is not needed.
The reason being that the TEXINPUTS path list was not quoted on Windows.
This was no problem with spaces but some special characters are
interpreted by the shell and can cause problems. In this particular
case, the '&' character was being interpreted as a command separator.
Some applications do not accept forward slashes, so call external viewers
and editors with backward slashes which is the usual convention under windows.
The option --enable-qt5 allows configuring for Qt5. The default is Qt4.
Nothing special is done with respect to Qt4, apart from pulling in the
correct libraries. Indeed, other than the core and gui libraries, now
also the concurrent and widgets libraries are needed.
The conversion from floating point to string performed by
boost:lexical_cast does not allow specifying a precision and,
for example, values such as 0.9 are resturned as 0.899999976.
The standard C++ way for performing the conversion is using
std::ostringstream which is exempt from this problem, even if
less efficient. For the sake of accuracy, boost::lexical_cast
is ditched in favor of the ostrinsgstream implementation.
In C++11 another option would be using std::to_string, but I
think it is not as efficient as the boost way and not worth
implementing through #ifdef's.
Incidentally, this patch would have also fixed#9190 and all
similar cases involving the use of convert<string>(float|double).
The compiler-generated copy-constructor and assigment operators would be wrong
for IconvProcessor::Impl, since cd would be copied, and iconv_close() could
thus be called twice on the same descriptor. The old code did work, but now
IconvProcessor::Impl cannot be copied by accident in the future.
The IconvProcessor assignment operator did not delete pimpl_ and used a
non-standard signature. If you want to know why the standard signature is
important, read "Effective C++" by Scott Meyers.
The magic library can detect the charset used by a file. While this
detection is not full proof, actually the library seems to be infallible
as regards the binary nature of a file. So, use libmagic for the detection
and fallback to the previous method if the library is not installed or
its database cannot be loaded.
On startup, the default locale is "C", meaning that all system
functions assume an ascii codeset. The environment's locale
settings should be selected by calling setlocale(LC_ALL,"").
This is done by Qt during the QCoreApplication initialization
but this inizialization is never performed for batch processing
and, as a result, LyX is not able to process files whose names
contain non-ascii characters. This is not an issue on Windows,
where the file names are always stored as UTF-16, so the call is
only performed for unix-like platforms (this also includes cygwin,
due to its own filenames management that allows using characters
which are forbidden to native programs).
FileName::tempName() created a new temp file name by using qt to create a
temporary file with a unique name, and then deleting that file and returning
the name. This was unsafe, since other processes or even other threads of the
running LyX could create files with the same name between deletion and then
using the temp name.
This is fixed by using the TempFile class instead. As a side effect, a few
cases where the temp files were not deleted after usage were fixed as well.
The only place that is still unsafe is createTmpDir().
The compiler generated copy constructor and assignment operator are wrong.
This could easily be fixed by implementing them manually, but a) they are
not needed, and b) the semantics would be unclear (should the copy point
to a new temp file or not?), so it is better to forbid them.
- The TempFile class guarantees to generate a file name, we are not limited to
100 tries of a predictable scheme anymore, which could break if LyX
frequently crashes.
- The temp file name generation has no race condition against another LyX
instance in the same directory anymore.
- Symlinks survive saving again (regression of 10364082c8).
If LyX does not know about a given file format, it may easily
happen that the format is recognized as "latex" and this causes
bug #9146. This patch limits the check for a latex format to
non-binary files. The strategy for deciding that a file has
binary content is the same as that adopted by the "less" program.
This also changes the type of an int to an ssize_t.
nRead is initialized as an ssize_t because it could
be negative. It is cast to a size_t for comparison
to the size of a vector, but only after we check
that nRead is not negative.
The format entries should be sorted according to the culture selected for the
UI. This was not the case previously, resulting in unexpected sorting of small
and capital letters. This is now fixed by using the standard C function
strcoll(). Qt does only offer similar functionality in Qt5, and this is not
mature enough yet to depend on it.
Unfortunately we have a report that strcoll() does not work on MSVC, however
this partial fix is better than nothing. The MSVC issue might also be a
configuration problem, since MS claims that strcoll() is supported. This
still needs to be checked.
The code for detecting python commands and substituting in the
correct prefix is now merged with what used to be libScriptSearch()
and is now renamed to commandPrep(). This commit does not change
any functionality and just improves organization to reduce the
chance of bugs in the future.
Now the replacement is done in startScript(). In addition to making
the code cleaner and more consistent, this commit fixes a bug where
"$$s" was not replaced when "latex=" was specified in the extra flags
of a converter.
Note that the temporary fix at 731b8610 is reverted with this commit.
This fixes an issue when compiling with C++11 flags on: the
objective-C clang compiler produces an error. This patch set
the -std option to ansi for the Objective-C sources.
for possible thread conflicts, of the sort Georg resolved at
6a30211f. I have made static variables const where possible,
and marked cases that looked potentially problematic with the
comment:
// FIXME THREAD
Many of these definitely are vulnerable to concurrent access, such
as the static variables declared at the start of output_latex.cpp.
Suppose, e.g., we were outputting latex and also displaying the
source of a different document.
I'd appreciate it if others could grep for "FIXME THREAD" and see
if some of these are harmless, or what.
This fixes an issue whe compiling with C++11 flags on: The
objective-C clang compiler produces an error. This patch waits
avoid including specific C++ flags and uses LYX_CPP_SPECIFIC_FLAGS
to store the confliciting flags (for the moment, just C++11).
QProcess::startDetached cannot provide environment variables. When the
environment variables are set using the latexEnvCmdPrefix, a console
window is shown every time a viewer is started.
On Windows, this reverts commit 5225821242.
Fixes: #9035.
it's easy to use the existing docstring routine, so I've commented
out the string version of lowercase I had introduced. I've left the
code in case someone else needs it later.
the name, in the hyperlink. Fixes bug #8792.
This also fixes a bug discovered while working on this code: The
params passed to GuiHyperlink were never used.
This is the result of the discussion on the list "2.1.0 Blocker". Thanks to
all contributors!
The main idea is to use thread-local storage for all static variables.
This solution does not need any mutex. For more details, see the comment in
unicode.h.
It is no longer needed, and it had a comment that it needed review...
Now anybody who tries to make a copy again is forced to think about it,
instead of trying and using possibly wrong semantics by accident.
The Messages::gui_lang_ variable is instantiated in the '#ifdef ENABLE_NLS' block. To prevent compile problems, we should also instantiate it when NLS is disabled.
Make sure that the configure script only checks features using the C++ compiler.
Also get rid of our last C files, since they are not compiled nor distributed anyway.
The path to the lyx binary is either <build_dir>/bin (CMake) or
<build_dir>/src (autotools). This means the po directory can be found one
directory up.
Since 00387b2a38 it is possible to construct a dummy Messages object
which does not translate at all. With the old gettext implementation, a
Messages object without a defined language would have used a language from
an environment variable. Therefore, the duplicate definition of _() is no
longer needed. This gettext removal was really a good idea!
This is done by handling explicitly a dummy Message object, where no parsing of mo file is attempted. This avoids in turn that the lyxerr object is used during initialization of a global dummy Message object.
