Bug summary

All's in the title.

Code for reproduction

from matplotlib.path import *
from matplotlib.transforms import *
from matplotlib.scale import LogTransform

get_path_collection_extents(
    Affine2D().scale(2, 3),
    [Path([(1, 2), (3, 4)])], [], [(0, 0)], IdentityTransform())
get_path_collection_extents(
    blended_transform_factory(IdentityTransform(), LogTransform(10)) + Affine2D().scale(2, 3),
    [Path([(1, 2), (3, 4)])], [], [(0, 0)], IdentityTransform())

Actual outcome

Both expressions evaluate to Bbox([[2.0, 6.0], [6.0, 12.0]]).

Expected outcome

The second expression is different.

Additional information

This probably has the same underlying cause as #7975 (implicit conversion of the non-affine transform to its affine component only). (I tried to add a warning for the deprecation in #7975 and ran into this bug.)
get_path_collection_extents is called by Collection.get_datalim; it may be possible to construct a more explicit example where the autoscaling is wrong for a suitably-constructed Collection.

Operating system

macos

Matplotlib Version

3.8.0.dev1803+gbba391d1b6

Matplotlib Backend

any

Python version

3.11.3

Jupyter version

No response

Installation

git checkout