[Gdal-dev] GDAL 1.2

[Frank Warmerdam]

Tim Sutton wrote:
> Hi
> 
> (With apologies for cross posting)
> 
> I just upgraded to gdal 1.2 from cvs. I was hoping it might resolve an issue I 
> am encountering with ogr seeming to omit shapes from one of the esri sample 
> datasets (countries.shp). However it doesnt :-( 
> 
> If I recall correctly my IRC discussion with on #qgis, this same file rendered 
> correctly using gdal 1.8. on another developers pc.
> 
> Do you have any thoughts on what might be causing this? Has anyone else 
> encountered similar problems?
> 
> I have put a screenie showing the problem here:
> 
> http://tim.suttonfamily.co.uk/cgi-bin/ids/index.cgi?mode=image&album=/qgis&image=ogr_problem.png
> 
> 
> You will notice the US, Angola and Russia are all missing...
> 
> aps02ts at linux:~/dev/cpp/qgis> gdal-config --version
> 1.2.0


Folks,

The mostly likely reason for problems with the current OGR Shapefile driver
on polygon files is that we now try to restructure polygons into multipolygons
if the have multiple islands.  This code is pretty new and somewhat risky.
Also, if QGIS doesn't handle multipolygons this will raise the issue.

My suggestion is to use ogrinfo to see if the US, Angola and Russia
polygons are actually present (presumably as multipolygons).  If not then the
bug is in OGR, and you should file a bug against it's bugzilla as promptly as
possible.  If the ogrinfo output looks fine then I would suggest reviewing
your multipolygon handling.

Finally, while the 1.2.0 is alpha, I would hope to progress to final release
fairly quickly.  It is therefor important to report any issues as soon as
possible if I am to fix them before the 1.2.0 release.

PS. I am on the qgis-developer list, and will endevour to read over any messages
that prominantly mention GDAL or OGR in the subject line.  I might miss them
though if the issue is buried deep in the message as I am on the list primarily
to skim what is going on rather than follow closely.

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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and watch the world go round - Rush    | Geospatial Programmer for Rent