[Qgis-developer] New GRASS plugin: a test drive

[Radim Blazek]

On Fri, Oct 16, 2015 at 8:49 PM, Pedro Venâncio
<pedrongvenancio at gmail.com> wrote:
> Hi Radim,I've just compile qgis and I'm getting this Segmentation fault,
> when editing a GRASS layer (point, line or polygon) with Node Tool:

It is most probably the problem with different off_t size in GRASS and
QGIS. I have already implemented fix, but the problem is how to get
real off_t size from GRASS. On Windows, it is now hard coded 8 bytes.
build_off_t_size was added to g.version but it will but available in
7.1. For now, you have to ensure that QGIS and GRASS are compiled with
the same off_t size (I am not sure how) or change in
qgsgrassprovider.cpp
  typedef off_t grass_off_t;
to
  typedef qint32 grass_off_t;
or
  typedef qint64 grass_off_t;
according to the size used in GRASS.

Radim

> Program received signal SIGSEGV, Segmentation fault.
> 0xb51e7c4a in _IO_vfprintf_internal (s=s at entry=0xbffa6fd0,
>     format=<optimized out>,
>     format at entry=0x92c09ea8 "Unable to rewrite feature/offset %lu in vector
> map <%s>", ap=ap at entry=0xbffa88e4 "\001") at vfprintf.c:2047
> 2047    vfprintf.c: Ficheiro ou directoria inexistente.
> (gdb) bt
> #0  0xb51e7c4a in _IO_vfprintf_internal (s=s at entry=0xbffa6fd0,
>     format=<optimized out>,
>     format at entry=0x92c09ea8 "Unable to rewrite feature/offset %lu in vector
> map <%s>", ap=ap at entry=0xbffa88e4 "\001") at vfprintf.c:2047
> #1  0xb529af01 in ___vsprintf_chk (
>     s=0xbffa70cc "Unable to rewrite feature/offset 1 in vector map
> <x\265\034q\372\277\034", <incomplete sequence \372\277>, flags=1,
> slen=2000,
>     format=0x92c09ea8 "Unable to rewrite feature/offset %lu in vector map
> <%s>", args=0xbffa88e4 "\001") at vsprintf_chk.c:84
> #2  0x92c23812 in ?? () from /usr/lib/grass70/lib/libgrass_gis.so
> #3  0x92c24007 in G_warning () from /usr/lib/grass70/lib/libgrass_gis.so
> #4  0x92bf4db5 in Vect_rewrite_line ()
>    from /usr/lib/grass70/lib/libgrass_vector.so
> #5  0x92cb9da5 in QgsGrassProvider::rewriteLine (this=0xcc35bc8, oldLid=1,
>     type=2, Points=0xc633520, Cats=0x9bbd0c8)
>     at