[PROJ] Serious confusion regarding towgs or not...!

[Even Rouault]

> Ah ah, that you rely entirely on PROJ to do always the "right thing" makes
> me equally nervous :-)
> Perhaps QGIS when ingesting a WKT1 string with a TOWGS84[] or a PROJ.4
> string with a +towgs84 should ask the user: "do you really want to use that
> precise transformation to WGS84 (which will thus make it the pivot CRS for
> datum transformations) or just use the underlying CRS and being proposed
> with several possibilities when transforming to other datums ?" Of course
> most users will have no clue at answering that question... Sometimes users
> implictly relied on the more or less arbitrary +towgs84 values that were
> picked up previously, and they will suffer from misalignment if using other
> transformations. So perhaps there should be a different behaviour if
> opening old QGIS projects than if creating new ones ? Just brainstorming

Thining about all the above, regarding GDAL, I've issued the following pull 
request that will change its behaviour regarding importFromEPSG(), to no 
longer try to attach a transformation to WGS84:

https://github.com/OSGeo/gdal/pull/2113


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