Empty arrays are 0, 1, 1, 1. Update isVector and tests.

Author: umar456

src/api/c/array.cpp

@@ -97,7 +97,10 @@ af_err af_create_handle(af_array *result, const unsigned ndims, const dim_t * co
         af_array out = 0;
         AF_CHECK(af_init());
 
-        dim4 d(0, 0, 0, 0);
+        if (ndims > 0) {
+            ARG_ASSERT(2, ndims > 0 && dims != NULL);
+        }
+        dim4 d(0);
         for(unsigned i = 0; i < ndims; i++) {
             d[i] = dims[i];
         }

src/api/cpp/array.cpp

@@ -127,7 +127,7 @@ namespace af
 
     array::array() : arr(0)
     {
-        initEmptyArray(&arr, f32, 0, 0, 0, 0);
+        initEmptyArray(&arr, f32, 0, 1, 1, 1);
     }
 
     array::array(const dim4 &dims, af::dtype ty) : arr(0)

src/backend/ArrayInfo.cpp

@@ -99,10 +99,12 @@ bool ArrayInfo::isColumn() const
 bool ArrayInfo::isVector() const
 {
     int singular_dims = 0;
+    int non_singular_dims = 0;
     for(int i = 0; i < AF_MAX_DIMS; i++) {
+        non_singular_dims += (dims()[i] != 0 && dims()[i] != 1);
         singular_dims += (dims()[i] == 1);
     }
-    return singular_dims == AF_MAX_DIMS - 1;
+    return singular_dims == AF_MAX_DIMS - 1 && non_singular_dims == 1;
 }
 
 bool ArrayInfo::isComplex() const

test/array.cpp

@@ -29,9 +29,6 @@ TEST(Array, ConstructorDefault)
     array a;
     EXPECT_EQ(0u,    a.numdims());
     EXPECT_EQ(dim_t(0),    a.dims(0));
-    EXPECT_EQ(dim_t(0),    a.dims(1));
-    EXPECT_EQ(dim_t(0),    a.dims(2));
-    EXPECT_EQ(dim_t(0),    a.dims(3));
     EXPECT_EQ(dim_t(0),    a.elements());
     EXPECT_EQ(f32,  a.type());
     EXPECT_EQ(0u,    a.bytes());
@@ -411,6 +408,11 @@ TEST(Array, ISSUE_951)
     af::array b = a.cols(0, 20).rows(10, 20);
 }
 
+TEST(Array, CreateHandleInvalidNullDimsPointer) {
+    af_array out = 0;
+    EXPECT_EQ(AF_ERR_ARG, af_create_handle(&out, 1, NULL, f32));
+}
+
 
 TEST(Device, simple)
 {