[Qgis-developer] Avoid segmentation fault on selection when commit

[Tim Sutton]

Hi Adrien

I suggest to attach this as a patch to the bug tracking system. Marco
probably would have a better idea of which solution you propose is
better.

Regards

Tim

2008/7/11 Adrien Gruson <agruson at archivideo.com>:
> Hi all,
> I develop Qgis plugin and I have a little problem with selections and
> commit.
> _
> Steps :_
>
>  1. You select added features (they have negative id).
>  2. You commit change (commit attribute positive id to added features)
>    but your mSelectedFeatureIds haven't updated and have always
>    negative Id in mSelectedFeatureIds.
>  3. If the user doesn't reselect features, you have a segmentation
>    fault because if you do a iteration on mSelectedFeatures there are
>    wrong id.
>
>
> _A possible solution :
>
> _
>
>  * Erase all negative ids in commitChanges
>
>  <http://doc.qgis.org/classQgsVectorLayer.html#fab34baf331320a8c3212993f5fccfa1>
>    ()
>
> Advantage : easy to do
> Disadvantage: user's selection change when he commit
>
>  * Provider return new id of added feature and replace in
>    mSelectedFeatureIds.
>
> Advantage :  no change for user when he commit.
> Disadvantage : more change to do in code.
>
> Ps: I attach patch of first solution.
>
> Index: /raid/homes/agruson/workspace/SVN_Src_Qgis/core/qgsvectorlayer.cpp
> ===================================================================
> --- /raid/homes/agruson/workspace/SVN_Src_Qgis/core/qgsvectorlayer.cpp
>  (revision 8751)
> +++ /raid/homes/agruson/workspace/SVN_Src_Qgis/core/qgsvectorlayer.cpp
>  (working copy)
> @@ -2476,6 +2476,14 @@
>     }
>     else
>     {
> +         //Remove all negative Id in selected features
> +         if(mSelectedFeatureIds.size() > 0)
> +         {
> +           for(QgsFeatureList::iterator it = mAddedFeatures.begin(); it !=
> mAddedFeatures.end(); ++it)
> +           {
> +               mSelectedFeatureIds.remove(it->featureId());
> +           }
> +         }
>       // done, remove features from the list
>       mAddedFeatures.clear();
>       addedFeaturesOk = TRUE;
>
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>
>



-- 
Tim Sutton
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