From 8918ca4d00061bcc2c64eee57d5781a8c51714ca Mon Sep 17 00:00:00 2001
From: Sheehan Olver <solver@mac.com>
Date: Thu, 2 Jul 2026 10:04:30 +0100
Subject: [PATCH] Only use subblockbandwidths for bandwidths when actually a
 BBB matrix

---
 src/BandedBlockBandedMatrix.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/BandedBlockBandedMatrix.jl b/src/BandedBlockBandedMatrix.jl
index 33b7eda..89aa2b3 100644
--- a/src/BandedBlockBandedMatrix.jl
+++ b/src/BandedBlockBandedMatrix.jl
@@ -511,7 +511,7 @@ function getindex(A::BandedBlockBandedMatrix{T}, KR::BlockRange{1}, JR::BlockRan
     _BandedBlockBandedMatrix(A.data[:,JR], axes(axes(A,1)[KR],1), (l-sh, u+sh), subblockbandwidths(A))
 end
 
-@inline function bandwidths(V::SubArray{T,2,<:AbstractMatrix,<:Tuple{BlockSlice1,BlockSlice1}}) where T
+@inline function bandwidths(::AbstractBandedBlockBandedLayout, V::SubArray{T,2,<:AbstractMatrix,<:Tuple{BlockSlice1,BlockSlice1}}) where T
     inblockbands(V) && return subblockbandwidths(parent(V))
     (-720,-720)
 end