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Hi Larry,

Thanks for your bug report.

Do you have the same problem with the C++ unit test ?

Unfornataly I do not have any Mac computer to test on.
I've looked at the code carefully but cannot see anything that may lead to that problem.
If you could add these three lines, that could help diagnose (line 188 of qgsatlascomposition.cpp):

QgsDebugMsg( QString( "provider: %1" ).arg( (long)provider, sizeof(void*), 16 ) );
QgsDebugMsg( QString( "feature_I: %1" ).arg( featureI ) );
QgsDebugMsg( QString( "feature id: %1" ).arg( mFeatureIds[featureI] ) );

(adding #include "qgslogger.h" at the beginning of the file)

Thanks

--
Hugo Mercier
Oslandia

Hi Hugo,

The crash happens at line# 167 (i.e., provider->featureAtId(...) ), so I placed the QgsDebugMsg lines before that call. Everything looks fine with the C++ test (for first feature of 4):

23: QDEBUG : TestQgsAtlasComposition::filename() src/core/composer/qgsatlascomposition.cpp: 167: (prepareForFeature) provider: 7fcbafaee8d0
23: QDEBUG : TestQgsAtlasComposition::filename() src/core/composer/qgsatlascomposition.cpp: 168: (prepareForFeature) feature_I: 0
23: QDEBUG : TestQgsAtlasComposition::filename() src/core/composer/qgsatlascomposition.cpp: 169: (prepareForFeature) feature id: 0

However, for the Python test the feature id is way off:

51: src/core/composer/qgsatlascomposition.cpp: 167: (prepareForFeature) provider: 7f97b4bef990
51: src/core/composer/qgsatlascomposition.cpp: 168: (prepareForFeature) feature_I: 4294967296

Doesn't produce the 3rd line of debug output, because mFeatureIds[featureI] is probably out of index. :^) So, it crashes there.

Something to do with the typedef unsigned int size_t, as defined in python/core/qgsgeometry.sip not being compatible with Mac. Hinted to here:

http://lists.osgeo.org/pipermail/qgis-developer/2008-November/005182.html

I hunted down the typedef for size_t (in system header) for Mac OS X 10.6, 10.7, 10.8 (the currently supported OS versions) and it's the same on all (32 or 64 bit):

MacOSX10.x.sdk/usr/include/i386/_types.h

#if defined(__GNUC__) && defined(__SIZE_TYPE__)
typedef __SIZE_TYPE__        __darwin_size_t;    /* sizeof() */
#else
typedef unsigned long        __darwin_size_t;    /* sizeof() */
#endif

Even though its under i386, it applies to 64 bit Macs as well (in include/machine/_types.h). Guessing that __SIZE_TYPE__ is not generally pre-defined, and defaults to an unsigned long, I changed the following in python/core/qgsgeometry.sip:

%If (WS_MACX)
typedef unsigned long size_t;
%End
%If (!WS_MACX)
typedef unsigned int size_t;
%End

I added some debug code to cmake/SIPMacros.cmake to see what -t flags were being sent to sip binary for building the bindings and found the 'WS_MACX' Platform tag.

http://www.riverbankcomputing.co.uk/static/Docs/sip4/directives.html#directive-%Platforms

Now both tests pass fine. However, the Python test took 10 times longer to complete (15 seconds for C++ and 155 for Python, on an older Mac Pro). That is by far the longest running test on the Mac. Not sure why it is so much longer under Python??

Need to test more on other Mac platforms and talk to some sip gurus before committing this.

Basically, it doesn't look like your code is causing the problem, just showing the symptoms of what a appears to be a longstanding issue. It just didn't show up until some of the Python bindings resolved to the size_t ctype on Mac.

Thanks for helping with this.

Fixed in changeset 332ce329afb61609f1f224eec41b552535437dfe.