cog.py: Fix test_cog_creation_of_overviews_with_compression.

[schwehr]

a -> b

Just a minor typo such that the second JPEG_QUALITY check was a repeat of the first.

[rouault]

would you mind replacing the whole block

    ds_overview_a = gdal.Open("GTIFF_DIR:2:" + filename)
    assert ds_overview_a.GetMetadata("IMAGE_STRUCTURE")["COMPRESSION"] == "JPEG"
    assert ds_overview_a.GetMetadata("IMAGE_STRUCTURE")["JPEG_QUALITY"] == "50"

    ds_overview_b = gdal.Open("GTIFF_DIR:3:" + filename)
    assert ds_overview_b.GetMetadata("IMAGE_STRUCTURE")["COMPRESSION"] == "JPEG"
    assert ds_overview_b.GetMetadata("IMAGE_STRUCTURE")["JPEG_QUALITY"] == "50"

    ds_overview_a = None
    ds_overview_b = None

with something like (pending correct indentation)

    with gdal.Open("GTIFF_DIR:2:" + filename) as ds:
        assert ds.GetMetadata("IMAGE_STRUCTURE")["COMPRESSION"] == "JPEG"
        assert ds.GetMetadata("IMAGE_STRUCTURE")["JPEG_QUALITY"] == "50"

    with gdal.Open("GTIFF_DIR:3:" + filename) as ds:
        assert ds.GetMetadata("IMAGE_STRUCTURE")["COMPRESSION"] == "JPEG"
        assert ds.GetMetadata("IMAGE_STRUCTURE")["JPEG_QUALITY"] == "50"

[schwehr]

Sure thing. That is definitely safer/better style. I will get it in a few hours or early tomorrow.

[schwehr]

@rouault , Ran pre-commit and force pushed your suggestion.

I need to use the with pattern like this more often in my code. Much clearer and less bug prone in many cases.