[gdal-dev] Shapefile with corrupted index: SHAPE_RESTORE_SHX=YES doesn't correctly repairs it.

[Andrea Giudiceandrea]

Hi Jan,
thank you very much for looking at this issue.

I had already managed to restore the .shx index file, as reported in my 
first message [1] [2] by fixing the GDAL/OGR SHPRestoreSHX routine [3]. 
Even Rouault also further improved it adding extra sanity checks, a 
better logic and better error messages [4].
Obviously, SHPRestoreSHX routing doesn't take care of the the mismatch 
between the shape and dbf records number.

An old but still working Shapefile recovery tool (which also handle the 
shp / dbf mismatch) is the "Shape Checker" [5].

The .idx file may have been created by AutoCAD [6], as the user reported 
that he tried to open the corrupted Shapefile layer with AutoCAD after 
the corruption occurred.

Best regards.

Andrea


[1] https://lists.osgeo.org/pipermail/gdal-dev/2023-May/057229.html
[2] https://github.com/qgis/QGIS/issues/53058#issuecomment-1547740971
[3] https://github.com/OSGeo/gdal/pull/7774
[4] https://github.com/OSGeo/gdal/pull/7778
[5] 
https://web.archive.org/web/20091024035556/http://geocities.com/SiliconValley/Haven/2295/howto_shapechk.html
[6] 
https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/Required-files-that-make-up-a-shapefile.html



Il 17/05/2023 12:39, Jan Heckman ha scritto:
> Hi all,
> 
> As noted in the QGis issues <https://github.com/qgis/QGIS/issues/53058>, 
> the shx has problems that ogr2ogr (or QGis Repair Shapefile) will not fix;
> The error I get in cmdline with SHAPE_RESTORE_SHX=YES is "ERROR 4: Error 
> parsing .shp to restore .shx".