Tolerance for comparison operations

[3DTOPO]

Feature description

I am unable to use the Select by location equals and Join Attributes by location functions because of tiny variations in what should be considered identical lines.

For instance, consider the bounding box of feature A:

<gml:lowerCorner>-12818885.0735037 5407394.84287971</gml:lowerCorner
<gml:upperCorner>-12814007.3953906 5420289.51805539</gml:upperCorner>

and the bounding box for feature B:

<gml:lowerCorner>-12818885.0735037 5407394.84287971</gml:lowerCorner
<gml:upperCorner>-12814007.3950567 5420289.51820939</gml:upperCorner>

They are identical to the 3rd decimal place, eg millimeters. It looks like the only solution to this is to using something like ST_SnapToGrid, but I would welcome any suggestions.

I'm not familiar with the codebase, but wouldn't it be trivial to perform rounding or truncation when comparing features? It would make the features much more useful.

Additional context

This open issue from 2018 states that tolerance has never been implemented:
#27207

[3DTOPO]

I just found the Simplify snap to grid feature, which allows me to change the precision.

It is nice to be able to do it in QGIS, but it would be very nice to have a tolerance parameter so the vector geometry doesn't have to be modified to find near-identical matches. It would also help search for similar features without creating a buffer.

[alexbruy]

Duplicates #27207.