crash in GPJ_grass_to_wkt() on windows

[jef]

QGIS crashes when calling GPJ_grass_to_wkt(), when the MinGW built libraries are called from MSVC build QGIS. This is caused to using G_free() on a string alloced in proj.4 with pj_malloc(). The attached patch free the string with pj_dalloc()

[jef]

patch to fix #468

[neteler]

The definition of pj_dalloc() is here: ​http://svn.osgeo.org/metacrs/proj/trunk/proj/src/pj_malloc.c

void
pj_dalloc(void *ptr) {
	free(ptr);
}

The definition of G_free() is here: ​http://trac.osgeo.org/grass/browser/grass/branches/develbranch_6/lib/gis/alloc.c#L127

void G_free(void *buf)
{
    free(buf);
}

Is there a difference?

[jef]

Replying to neteler:

The definition of pj_dalloc() is here: ​http://svn.osgeo.org/metacrs/proj/trunk/proj/src/pj_malloc.c

void
pj_dalloc(void *ptr) {
	free(ptr);
}

The definition of G_free() is here: ​http://trac.osgeo.org/grass/browser/grass/branches/develbranch_6/lib/gis/alloc.c#L127

void G_free(void *buf)
{
    free(buf);
}

Is there a difference?

sure. Every DLL runs it own memory management and therefore memory malloc() in a one DLL needs to be free by the very same DLL and that's probably the sole reason for the existance of above functions (same for GDAL, GEOS...).

[jef]

Replying to jef:

sure. Every DLL runs it own memory management and therefore memory malloc() in a one DLL needs to be free by the very same DLL and that's probably the sole reason for the existance of above functions (same for GDAL, GEOS...).

Did you also have a dejavu? ;) ​http://trac.osgeo.org/gdal/ticket/1983

[pkelly]

I fixed this in TRUNK, and fixed a few memory leaks at the same time. The changes are too complicated/risky to backport to 6.x though, so the simple patch attached here should be OK for a quick fix.

[neteler]

jef's patch applied to 6.4.svn (r35668) and 6.4.0svn (r35669).