From 68869daa5f07337478089e3ef963a4d293280f21 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lars=20G=C3=B6ttgens?= <lars.goettgens@rwth-aachen.de>
Date: Mon, 15 Dec 2025 16:17:25 +0100
Subject: [PATCH] Switch delegation order of `sub` and `getindex` for
 submatrices

---
 src/Matrix.jl | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/Matrix.jl b/src/Matrix.jl
index 1c3743b258..a34ad85fc7 100644
--- a/src/Matrix.jl
+++ b/src/Matrix.jl
@@ -437,16 +437,7 @@ Instead of a vector, `rows` and `cols` can also be:
 * an integer `i`, which is  interpreted as `i:i`, or
 * `:`, which is interpreted as `1:nrows(M)` or `1:ncols(M)` respectively.
 """
-function getindex(M::MatElem, rows::AbstractVector{Int}, cols::AbstractVector{Int})
-   _checkbounds(M, rows, cols)
-   A = similar(M, length(rows), length(cols))
-   for i in 1:length(rows)
-      for j in 1:length(cols)
-         A[i, j] = deepcopy(M[rows[i], cols[j]])
-      end
-   end
-   return A
-end
+getindex(M::MatElem, r::AbstractVector{<:Integer}, c::AbstractVector{<:Integer}) = sub(M, r, c)
 
 function getindex(M::MatElem, i::Int, cols::AbstractVector{Int})
    _checkbounds(M, i, cols)
@@ -472,8 +463,16 @@ getindex(M::MatElem, rows, ::Colon) = getindex(M, rows, 1:ncols(M))
 
 getindex(M::MatElem, ::Colon, ::Colon) = getindex(M, 1:nrows(M), 1:ncols(M))
 
-
-sub(M::MatElem, r::AbstractVector{<:Integer}, c::AbstractVector{<:Integer}) = M[r, c]
+function sub(M::MatElem, rows::AbstractVector{Int}, cols::AbstractVector{Int})
+   _checkbounds(M, rows, cols)
+   A = similar(M, length(rows), length(cols))
+   for i in 1:length(rows)
+      for j in 1:length(cols)
+         A[i, j] = deepcopy(M[rows[i], cols[j]])
+      end
+   end
+   return A
+end
 
 # fallback method that converts Colons to UnitRanges
 function Base.view(M::MatElem, rows, cols)