scale_row! fixed (#1476)

thofma · May 1, 2024 · 969c5f5 · 969c5f5
1 parent 3ed50fd
commit 969c5f5
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Showing 2 changed files with 12 additions and 1 deletion.
diff --git a/src/Sparse/Row.jl b/src/Sparse/Row.jl
@@ -425,8 +425,15 @@ function scale_row!(a::SRow{T}, b::T) where T
   if isone(b)
     return
   end
-  for i=1:length(a.pos)
+  i = 1
+  while i <= length(a)
     a.values[i] *= b
+    if iszero(a.values[i])
+      deleteat!(a.values, i)
+      deleteat!(a.pos, i)
+    else
+     i += 1
+    end
   end
 end
 

diff --git a/test/Sparse/Row.jl b/test/Sparse/Row.jl
@@ -1,5 +1,6 @@
 @testset "Row" begin
   R = FlintZZ
+  S, _ = residue_ring(ZZ, 4)
 
   # Construction
 
@@ -82,7 +83,10 @@
 
   A = sparse_row(FlintZZ, [1, 2, 4], ZZRingElem[1, 2, 3])
   scale_row!(A, ZZRingElem(2))
+  B = sparse_row(S, [1, 3, 4], [1, 2, 3])
+  scale_row!(B, S(2))
   @test A == sparse_row(FlintZZ, [1, 2, 4], ZZRingElem[2, 4, 6])
+  @test B == sparse_row(S, [1, 4], [2, 2])
 
   # Addition
   A = sparse_row(FlintZZ, [1, 2, 3, 5], ZZRingElem[1, 2, 3, 5])