fTools fail to rename duplicated field names if they are 10 char long

[borysiasty]

If I join two tables containing common 10-char-long field name, fTools try to add the "_" char to one of them, then truncate it and fail to write, with no warning message. Could it rename the field name in a more robust way or at least warn that the layer won't be created and why?

[borysiasty]

I've just realized it's a common issue in all fTools.

[alexbruy]

This is not an fTools issue, this is limitation of ESRI Shapefile format (exactly DBF format). Field name must be <= 10 characters.

Here is patch to add some warnings to the "Join by attributes" and "Spatial join" tools

[alexbruy]

proposed patch

[borysiasty]

The warnings are necessary, but I still suggest to truncate names to 8 characters before adding the suffix. It's extremely easy to implement and can help in many cases (not in all, of course).

[alexbruy]

Ok, here is another patch. Long names are truncated to 8 characters and then suffix added. But in this case warning are not necessary I think and we can remove it.

[borysiasty]

They're still necessary, as one can have more than 2 affected fields. E.g. both "foobarfoo1" and "foobarfoo2" in both tables. It would be the best to add a computed suffix _(n+1) (thought it's still not ideal, as it could cause confusions)

[alexbruy]

Replying to borysiasty:

It would be the best to add a computed suffix _(n+1) (thought it's still not ideal, as it could cause confusions)

As far as I see computed suffixes _(n+1) are used

[borysiasty]

Sorry, my fault! I've look too briefly into the code!

Anyway, I believe we should keep the warnings for a case if one has more than 9 very long names with common prefix in a non-dbf table (e.g. fobarfoo_temperature, fobarfoo_precipitation etc).

[cfarmer]

Patch applied in r13313.

Carson