the old behavior is explicitly tested for, but I think those tests are incorrect, right?

This seems to have some overlap with #30950, although it's much smaller in scope. I fear this will be complicated and might be breaking. The axis of an axis is often ignored -- incorrectly -- but that behavior is ancient.

note the following consequence:

julia> using OffsetArrays

julia> a1 = OffsetArray(Int[], 4);

julia> a2 = OffsetArray(Int[], 5);

julia> a1 == a2, axes(a1) == axes(a2)
(true, true)

julia> cmp(a1, a2), cmp(axes(a1), axes(a2))
(-1, -1)

ancient or not, shouldn't we fix it?

Please go ahead by all means, I'm not vetoing this. I'll just be interested in a PkgEval run to see if this impacts the ecosystem.

@nanosoldier runtests()

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@nanosoldier runtests(["MethodInspector", "LazyModules", "UnzipLoops", "AssociatedLegendrePolynomials", "OddEvenIntegers", "PaddedViews", "CatIndices", "OffsetArrays", "TypeUtils", "RunningQuantiles", "LocalFilters", "IntegralArrays", "GeometricSolutions", "DataFlowTasks", "LACosmic", "ArrayInterfaceOffsetArrays", "TiledIteration", "FFTViews", "HistogramThresholding", "Sixel", "ImageTransformations", "FoldRNA", "Groebner", "AxisKeys", "PSRDatabase", "ImageSmooth", "ImageFiltering", "BasicTextRender", "SPECTrecon", "TrainingPhantoms", "SMLMMetrics", "GeoArrayOps", "ImageMorphology", "ImageEdgeDetection", "HierarchicalTemporalMemory", "ImageIO", "CompactBasisFunctions", "Augmentor", "BackgroundMeshes", "ImageInpainting", "MRICompress", "SMLMFrameConnection", "ImageQualityIndexes", "QuantitativeSusceptibilityMappingTGV", "CellSegmentation", "DeepFry", "CloudCovErr", "SpmGrids", "InstrumentOperator", "Photometry", "SimSpin", "ImgCIFHandler", "UVITTools", "PulseInputDDM", "Regions", "Ditherings", "MPITestImages", "Eikonal", "HoloProcessing", "ChaoticEncryption", "RemBG", "ComplexPhasePortrait", "ImageProjectiveGeometry", "Radiomics", "GigaScatter", "BundlerIO", "OtsuThresholding", "ImageUtils", "SpaSM", "CoralBlox", "PerceptualColourMaps", "UnfoldSim", "WebToys", "ImageHashes", "OliveImages", "AIBECS", "FinEtoolsVoxelMesher", "Colocalization", "Fable", "PGFPlots", "ChemfilesViewer", "FaceDetection", "Mellan", "Basins", "CriticalDifferenceDiagrams", "Repotomata", "ElectroPhysiology", "MPIReco", "PhysiologyPlotting", "FatDatasets", "Jchemo", "BlobTracking", "IceFloeTracker", "MAGEMinApp", "PhysiologyAnalysis", "HeartRateVariability", "JHistint", "LineIntegralConvolution", "Javis", "OrbisChessEngine", "MRINavigator", "Ecosons", "HmtGutenberg", "HmtArchive", "Graphene", "UnfoldMakie", "Mads", "MiseEnPage", "CanDecomp", "Test", "NeuroAnalysis", "NTFk", "SmartML", "NTNk", "GeoThermalCloud", "FundamentalsNumericalComputation", "GasChromatographySystems"])

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