[PATCH] Fix memleak in OGRILI1Layer::JoinSurfaceLayer()

[Even Rouault]

​https://api.travis-ci.org/jobs/104435908/log.txt?deansi=true reports on ogr_ili.py (and confirmed by Valgrind)

Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7fd45694fd9a in operator new(unsigned long) (/home/travis/build/rouault/gdal_coverage/install-gcc-5.2.0/lib64/libasan.so.2.0.0+0x97d9a)
    #1 0x7fd446dd91a6 in OGRILI1Layer::JoinSurfaceLayer(OGRILI1Layer*, int) /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/ili/ogrili1layer.cpp:533
    #2 0x7fd446dd6b4b in OGRILI1Layer::JoinGeomLayers() /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/ili/ogrili1layer.cpp:463
    #3 0x7fd446dcb547 in OGRILI1Layer::GetNextFeature() /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/ili/ogrili1layer.cpp:103
    #4 0x7fd446e5e898 in OGR_L_GetNextFeature /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/generic/ogrlayer.cpp:550
    #5 0x7fd431dc0458 in OGRLayerShadow_GetNextFeature extensions/ogr_wrap.cpp:3845
    #6 0x7fd431dc0458 in _wrap_Layer_GetNextFeature extensions/ogr_wrap.cpp:8738

Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7fd45694fd9a in operator new(unsigned long) (/home/travis/build/rouault/gdal_coverage/install-gcc-5.2.0/lib64/libasan.so.2.0.0+0x97d9a)
    #1 0x7fd447b8a6b0 in OGRCompoundCurve::clone() const /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrcompoundcurve.cpp:217
    #2 0x7fd446dd9193 in OGRILI1Layer::JoinSurfaceLayer(OGRILI1Layer*, int) /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/ili/ogrili1layer.cpp:531
    #3 0x7fd446dd6b4b in OGRILI1Layer::JoinGeomLayers() /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/ili/ogrili1layer.cpp:463
    #4 0x7fd446dcb547 in OGRILI1Layer::GetNextFeature() /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/ili/ogrili1layer.cpp:103
    #5 0x7fd446e5e898 in OGR_L_GetNextFeature /home/travis/build/rouault/gdal_coverage/gdal/ogr/ogrsf_frmts/generic/ogrlayer.cpp:550
    #6 0x7fd431dc0458 in OGRLayerShadow_GetNextFeature extensions/ogr_wrap.cpp:3845
    #7 0x7fd431dc0458 in _wrap_Layer_GetNextFeature extensions/ogr_wrap.cpp:8738

The proposed patch fixes that, but given the non obvious logic of this method, it should be check by more expert eyes.

[pka]

Looks good to me, thanks! For me it's ok to have the leak in 2.0.2, because the behaviour with same geometry was much worse before (crash or wrong results).

[Even Rouault]

Replying to pka:

Looks good to me, thanks! For me it's ok to have the leak in 2.0.2, because the behaviour with same geometry was much worse before (crash or wrong results).

ok, I let you apply in trunk and branches/2.0 ? I agree it is probably not critical enough to call for a new 2.0.2 RC

[Even Rouault]

Hum, as I finally want to issue another RC for other reasons :

trunk r33155, branches/2.0 r33156 "ILI1: fix memory leak in OGRILI1Layer::JoinSurfaceLayer() (#6329)"

(but I now realize there are other leaks I've fixed in trunk in other parts of the driver)