Fixed #38346: Eigen decomposition of Symmetric Matrix containing NaNs…

… now throws exception (#38408)

(cherry picked from commit a813a6e)

stdlib/LinearAlgebra/src/lapack.jl

@@ -95,6 +95,24 @@ function chkfinite(A::AbstractMatrix)
     return true
 end
 
+function chkuplofinite(A::AbstractMatrix, uplo::AbstractChar)
+    require_one_based_indexing(A)
+    m, n = size(A)
+    if uplo == 'U'
+        @inbounds for j in 1:n, i in 1:j
+            if !isfinite(A[i,j])
+                throw(ArgumentError("matrix contains Infs or NaNs"))
+            end
+        end
+    else
+        @inbounds for j in 1:n, i in j:m
+            if !isfinite(A[i,j])
+                throw(ArgumentError("matrix contains Infs or NaNs"))
+            end
+        end
+    end
+end
+
 # LAPACK version number
 function version()
     major = Ref{BlasInt}(0)
@@ -5030,6 +5048,7 @@ for (syev, syevr, sygvd, elty) in
                         vl::AbstractFloat, vu::AbstractFloat, il::Integer, iu::Integer, abstol::AbstractFloat)
             chkstride1(A)
             n = checksquare(A)
+            chkuplofinite(A, uplo)
             if range == 'I' && !(1 <= il <= iu <= n)
                 throw(ArgumentError("illegal choice of eigenvalue indices (il = $il, iu = $iu), which must be between 1 and n = $n"))
             end

stdlib/LinearAlgebra/test/eigen.jl

@@ -101,8 +101,12 @@ end
         @test_throws(ArgumentError, eigen(fill(eltya, 1, 1)))
         @test_throws(ArgumentError, eigen(fill(eltya, 2, 2)))
         test_matrix = rand(typeof(eltya),3,3)
-        test_matrix[2,2] = eltya
+        test_matrix[1,3] = eltya
         @test_throws(ArgumentError, eigen(test_matrix))
+        @test_throws(ArgumentError, eigen(Symmetric(test_matrix)))
+        @test_throws(ArgumentError, eigen(Hermitian(test_matrix)))
+        @test eigen(Symmetric(test_matrix, :L)) isa Eigen
+        @test eigen(Hermitian(test_matrix, :L)) isa Eigen
     end
 end