Fixing 0 length issue with constructor

src/libraries/System.Numerics.Tensors/src/System/Numerics/Tensors/netcore/ReadOnlyTensorSpan.cs

@@ -129,7 +129,7 @@ public ReadOnlyTensorSpan(ReadOnlySpan<T> span, scoped ReadOnlySpan<nint> length
             strides = strides.IsEmpty ? (ReadOnlySpan<nint>)TensorSpanHelpers.CalculateStrides(lengths, linearLength) : strides;
             TensorSpanHelpers.ValidateStrides(strides, lengths);
             nint maxElements = TensorSpanHelpers.ComputeMaxLinearIndex(strides, lengths);
-            if (maxElements >= span.Length && span.Length != 0)
+            if (span.IsEmpty ? maxElements != 0 : maxElements >= span.Length)
                 ThrowHelper.ThrowArgument_InvalidStridesAndLengths();
 
             _shape = new TensorShape(span.Length, lengths, strides);

src/libraries/System.Numerics.Tensors/src/System/Numerics/Tensors/netcore/TensorSpan.cs

@@ -132,7 +132,7 @@ public TensorSpan(Span<T> span, scoped ReadOnlySpan<nint> lengths, scoped ReadOn
             TensorSpanHelpers.ValidateStrides(strides, lengths);
 
             nint maxElements = TensorSpanHelpers.ComputeMaxLinearIndex(strides, lengths);
-            if (maxElements >= span.Length && span.Length != 0)
+            if (span.IsEmpty ? maxElements != 0 : maxElements >= span.Length)
                 ThrowHelper.ThrowArgument_InvalidStridesAndLengths();
 
             _shape = new TensorShape(span.Length, lengths, strides);

src/libraries/System.Numerics.Tensors/src/System/Numerics/Tensors/netcore/TensorSpanHelpers.cs

@@ -193,7 +193,8 @@ public static nint ComputeLinearIndex(ReadOnlySpan<NIndex> indexes, ReadOnlySpan
 
         public static void ValidateStrides(ReadOnlySpan<nint> strides, ReadOnlySpan<nint> lengths)
         {
-            Debug.Assert(strides.Length == lengths.Length);
+            if (strides.Length != lengths.Length)
+                ThrowHelper.ThrowArgument_InvalidStridesAndLengths();
 
             if (strides.Length == 0)
                 return;

src/libraries/System.Numerics.Tensors/tests/ReadOnlyTensorSpanTests.cs

@@ -224,6 +224,11 @@ public static void ReadOnlyTensorSpanSystemArrayConstructorTests()
         [Fact]
         public static void ReadOnlyTensorSpanArrayConstructorTests()
         {
+            // Make sure exception is thrown if lengths and strides would let you go past the end of the array
+            Assert.Throws<ArgumentException>(() => new TensorSpan<double>(new double[0], lengths: new IntPtr[] { 2 }, strides: new IntPtr[] { 1 }));
+            Assert.Throws<ArgumentException>(() => new TensorSpan<double>(new double[1], lengths: new IntPtr[] { 2 }, strides: new IntPtr[] { 1 }));
+            Assert.Throws<ArgumentException>(() => new TensorSpan<double>(new double[2], lengths: new IntPtr[] { 2 }, strides: new IntPtr[] { 2 }));
+
             // Make sure basic T[] constructor works
             int[] a = { 91, 92, -93, 94 };
             scoped ReadOnlyTensorSpan<int> spanInt = new ReadOnlyTensorSpan<int>(a);

src/libraries/System.Numerics.Tensors/tests/TensorSpanTests.cs

@@ -765,6 +765,11 @@ public static void TensorSpanSystemArrayConstructorTests()
         [Fact]
         public static void TensorSpanArrayConstructorTests()
         {
+            // Make sure exception is thrown if lengths and strides would let you go past the end of the array
+            Assert.Throws<ArgumentException>(() => new TensorSpan<double>(new double[0], lengths: new IntPtr[] { 2 }, strides: new IntPtr[] { 1 }));
+            Assert.Throws<ArgumentException>(() => new TensorSpan<double>(new double[1], lengths: new IntPtr[] { 2 }, strides: new IntPtr[] { 1 }));
+            Assert.Throws<ArgumentException>(() => new TensorSpan<double>(new double[2], lengths: new IntPtr[] { 2 }, strides: new IntPtr[] { 2 }));
+
             // Make sure basic T[] constructor works
             int[] a = { 91, 92, -93, 94 };
             scoped TensorSpan<int> spanInt = new TensorSpan<int>(a);