Add check_and_adjust_index(), and replace most index checks with it.

This commit adds a check_and_adjust_index(npy_intp *index, npy_intp max, int axis) function
which checks index against max, setting an IndexError and returning -1 if it's not valid,
and otherwise adjusting index in-place to handle Python's negative indexing, and returning 0.

It also changes most places in the code where indexes were being checked and adjusted with a
call to this function.

10 files changed, 105 insertions, 216 deletions

diff --git a/numpy/core/src/multiarray/arraytypes.c.src b/numpy/core/src/multiarray/arraytypes.c.src
index 0296d4063..c512025b1 100644
--- a/numpy/core/src/multiarray/arraytypes.c.src
+++ b/numpy/core/src/multiarray/arraytypes.c.src
@@ -3527,15 +3527,8 @@ static int
         for (i = 0; i < n_outer; i++) {
             for (j = 0; j < m_middle; j++) {
                 tmp = indarray[j];
-                if ((tmp < -nindarray) || (tmp >= nindarray)) {
-                    PyErr_Format(PyExc_IndexError,
-                                 "index %"NPY_INTP_FMT" out of bounds in dimension %"NPY_INTP_FMT,
-                                 tmp, j);
+                if (check_and_adjust_index(&tmp, nindarray, (int) j) < 0)
                     return 1;
-                }
-                if (tmp < 0) {
-                    tmp = tmp + nindarray;
-                }
                 if (nelem == 1) {
                     *dest++ = *(src + tmp);
                 }
diff --git a/numpy/core/src/multiarray/common.c b/numpy/core/src/multiarray/common.c
index db255025d..a704fd1ad 100644
--- a/numpy/core/src/multiarray/common.c
+++ b/numpy/core/src/multiarray/common.c
@@ -506,28 +506,63 @@ _array_typedescr_fromstr(char *c_str)
     return descr;
 }
 
+NPY_NO_EXPORT int
+check_and_adjust_index(npy_intp *index, npy_intp max_item, int axis)
+{
+    /* Check that index is valid, taking into account negative indices */
+    if ((*index < -max_item) || (*index >= max_item)) {
+        /* Try to be as clear as possible about what went wrong. */
+        if (axis >= 0) {
+            if (max_item > 0) {
+                PyErr_Format(PyExc_IndexError,
+                             "index %"NPY_INTP_FMT" is out of bounds for axis %d: "
+                             "[%"NPY_INTP_FMT",%"NPY_INTP_FMT")",
+                             *index, axis,
+                             -max_item, max_item);
+            } else {
+                PyErr_Format(PyExc_IndexError,
+                             "index %"NPY_INTP_FMT" is out of bounds for 0-d axis %d",
+                             *index, axis);
+            }
+        } else {
+            if (max_item > 0) {
+                PyErr_Format(PyExc_IndexError,
+                             "index %"NPY_INTP_FMT" is out of bounds: "
+                             "[%"NPY_INTP_FMT",%"NPY_INTP_FMT")",
+                             *index,
+                             -max_item, max_item);
+            } else {
+                /* I don't believe there are currently any cases where this occurs. */
+                PyErr_Format(PyExc_IndexError,
+                             "index %"NPY_INTP_FMT" is out of bounds for 0-d axis",
+                             *index);
+            }
+        }
+        return -1;
+    }
+    /* adjust negative indices */
+    if (*index < 0) {
+        *index += max_item;
+    }
+    return 0;
+}
+
 NPY_NO_EXPORT char *
 index2ptr(PyArrayObject *mp, npy_intp i)
 {
     npy_intp dim0;
-    npy_intp orig_i = i;  /* in case of error. */
 
     if (PyArray_NDIM(mp) == 0) {
         PyErr_SetString(PyExc_IndexError, "0-d arrays can't be indexed");
         return NULL;
     }
     dim0 = PyArray_DIMS(mp)[0];
-    if (i < 0) {
-        i += dim0;
-    }
-    if (i == 0 && dim0 > 0) {
+    if (check_and_adjust_index(&i, dim0, 0) < 0)
+        return NULL;
+    if (i == 0) {
         return PyArray_DATA(mp);
     }
-    if (i > 0 && i < dim0) {
-        return PyArray_DATA(mp)+i*PyArray_STRIDES(mp)[0];
-    }
-    PyErr_Format(PyExc_IndexError, "index %"NPY_INTP_FMT" out of bounds in dimension 0", orig_i);
-    return NULL;
+    return PyArray_DATA(mp)+i*PyArray_STRIDES(mp)[0];
 }
 
 NPY_NO_EXPORT int
diff --git a/numpy/core/src/multiarray/common.h b/numpy/core/src/multiarray/common.h
index 60b4008d8..085a91d01 100644
--- a/numpy/core/src/multiarray/common.h
+++ b/numpy/core/src/multiarray/common.h
@@ -41,6 +41,15 @@ _array_find_python_scalar_type(PyObject *op);
 NPY_NO_EXPORT PyArray_Descr *
 _array_typedescr_fromstr(char *str);
 
+/* 
+ * Returns -1 and sets an exception if *index is an invalid index for
+ * an array of size max_item, otherwise adjusts it in place to be
+ * 0 <= *index < max_item, and returns 0.
+ * If axis >= 0, it will be reported as part of the exception.
+ */
+NPY_NO_EXPORT int
+check_and_adjust_index(npy_intp *index, npy_intp max_item, int axis);
+
 NPY_NO_EXPORT char *
 index2ptr(PyArrayObject *mp, npy_intp i);
 
diff --git a/numpy/core/src/multiarray/ctors.c b/numpy/core/src/multiarray/ctors.c
index c8548f894..12c2ccad5 100644
--- a/numpy/core/src/multiarray/ctors.c
+++ b/numpy/core/src/multiarray/ctors.c
@@ -2925,6 +2925,7 @@ PyArray_CheckAxis(PyArrayObject *arr, int *axis, int flags)
 {
     PyObject *temp1, *temp2;
     int n = PyArray_NDIM(arr);
+    int axis_orig = *axis;
 
     if (*axis == NPY_MAXDIMS || n == 0) {
         if (n != 1) {
@@ -2967,7 +2968,7 @@ PyArray_CheckAxis(PyArrayObject *arr, int *axis, int flags)
     }
     if ((*axis < 0) || (*axis >= n)) {
         PyErr_Format(PyExc_ValueError,
-                     "axis(=%d) out of bounds", *axis);
+                     "axis(=%d) out of bounds", axis_orig);
         Py_DECREF(temp2);
         return NULL;
     }
diff --git a/numpy/core/src/multiarray/descriptor.c b/numpy/core/src/multiarray/descriptor.c
index 4bfcd3488..babbbc9b7 100644
--- a/numpy/core/src/multiarray/descriptor.c
+++ b/numpy/core/src/multiarray/descriptor.c
@@ -3383,18 +3383,19 @@ descr_subscript(PyArray_Descr *self, PyObject *op)
         PyObject *name;
         int size = PyTuple_GET_SIZE(self->names);
         int value = PyArray_PyIntAsInt(op);
+        int orig_value = value;
 
         if (PyErr_Occurred()) {
             return NULL;
         }
-        if (value < -size || value >= size) {
-            PyErr_Format(PyExc_IndexError,
-                         "Field index %d out of range.", value);
-            return NULL;
-        }
         if (value < 0) {
             value += size;
         }
+        if (value < 0 || value >= size) {
+            PyErr_Format(PyExc_IndexError,
+                         "Field index %d out of range.", orig_value);
+            return NULL;
+        }
         name = PyTuple_GET_ITEM(self->names, value);
         retval = descr_subscript(self, name);
     }
diff --git a/numpy/core/src/multiarray/item_selection.c b/numpy/core/src/multiarray/item_selection.c
index 89ad3eb17..b7440e7c1 100644
--- a/numpy/core/src/multiarray/item_selection.c
+++ b/numpy/core/src/multiarray/item_selection.c
@@ -174,16 +174,10 @@ PyArray_TakeFrom(PyArrayObject *self0, PyObject *indices0, int axis,
             for (i = 0; i < n; i++) {
                 for (j = 0; j < m; j++) {
                     tmp = ((npy_intp *)(PyArray_DATA(indices)))[j];
-                    if ((tmp < -max_item) || (tmp >= max_item)) {
-                        PyErr_Format(PyExc_IndexError,
-                                     "index %"NPY_INTP_FMT" out of range for array in dimension %"NPY_INTP_FMT,
-                                     tmp, axis);
+                    if (check_and_adjust_index(&tmp, max_item, axis) < 0) {
                         NPY_AUXDATA_FREE(transferdata);
                         goto fail;
                     }
-                    if (tmp < 0) {
-                        tmp = tmp + max_item;
-                    }
                     maskedstransfer(dest, itemsize,
                                     src + tmp*chunk, itemsize,
                                     (npy_mask *)(src_maskna + tmp*nelem), 1,
@@ -253,16 +247,9 @@ PyArray_TakeFrom(PyArrayObject *self0, PyObject *indices0, int axis,
             for (i = 0; i < n; i++) {
                 for (j = 0; j < m; j++) {
                     tmp = ((npy_intp *)(PyArray_DATA(indices)))[j];
-                    if ((tmp < -max_item) || (tmp >= max_item)) {
-                        PyErr_Format(PyExc_IndexError,
-                                     "index %"NPY_INTP_FMT" out of range for "
-                                     "array in dimension %"NPY_INTP_FMT,
-                                     tmp, axis);
+                    if (check_and_adjust_index(&tmp, max_item, axis) < 0) {
                         goto fail;
                     }
-                    if (tmp < 0) {
-                        tmp = tmp + max_item;
-                    }
                     memmove(dest, src + tmp*chunk, chunk);
                     dest += chunk;
                 }
@@ -391,14 +378,7 @@ PyArray_PutTo(PyArrayObject *self, PyObject* values0, PyObject *indices0,
             for (i = 0; i < ni; i++) {
                 src = PyArray_DATA(values) + chunk*(i % nv);
                 tmp = ((npy_intp *)(PyArray_DATA(indices)))[i];
-                if (tmp < 0) {
-                    tmp = tmp + max_item;
-                }
-                if ((tmp < 0) || (tmp >= max_item)) {
-                    /* TODO: should report out-of-range indices with axis */
-                    PyErr_SetString(PyExc_IndexError,
-                            "index out of " \
-                            "range for array");
+                if (check_and_adjust_index(&tmp, max_item, 0) < 0) {
                     goto fail;
                 }
                 PyArray_Item_INCREF(src, PyArray_DESCR(self));
@@ -448,14 +428,7 @@ PyArray_PutTo(PyArrayObject *self, PyObject* values0, PyObject *indices0,
             for (i = 0; i < ni; i++) {
                 src = PyArray_DATA(values) + chunk * (i % nv);
                 tmp = ((npy_intp *)(PyArray_DATA(indices)))[i];
-                if (tmp < 0) {
-                    tmp = tmp + max_item;
-                }
-                if ((tmp < 0) || (tmp >= max_item)) {
-                    /* TODO: should report out-of-range indices with axis */
-                    PyErr_SetString(PyExc_IndexError,
-                            "index out of " \
-                            "range for array");
+                if (check_and_adjust_index(&tmp, max_item, 0) < 0) {
                     goto fail;
                 }
                 memmove(dest + tmp * chunk, src, chunk);
@@ -1106,6 +1079,7 @@ PyArray_Sort(PyArrayObject *op, int axis, NPY_SORTKIND which)
     PyArrayObject *ap = NULL, *store_arr = NULL;
     char *ip;
     int i, n, m, elsize, orign;
+    int axis_orig=axis;
 
     n = PyArray_NDIM(op);
     if ((n == 0) || (PyArray_SIZE(op) == 1)) {
@@ -1115,7 +1089,7 @@ PyArray_Sort(PyArrayObject *op, int axis, NPY_SORTKIND which)
         axis += n;
     }
     if ((axis < 0) || (axis >= n)) {
-        PyErr_Format(PyExc_ValueError, "axis(=%d) out of bounds", axis);
+        PyErr_Format(PyExc_ValueError, "axis(=%d) out of bounds", axis_orig);
         return -1;
     }
     if (!PyArray_ISWRITEABLE(op)) {
@@ -2530,14 +2504,7 @@ PyArray_MultiIndexGetItem(PyArrayObject *self, npy_intp *multi_index)
             npy_intp shapevalue = shape[idim];
             npy_intp ind = multi_index[idim];
 
-            if (ind < 0) {
-                ind += shapevalue;
-            }
-
-            if (ind < 0 || ind >= shapevalue) {
-                PyErr_Format(PyExc_IndexError,
-                             "index %"NPY_INTP_FMT" out of bounds in dimension %d",
-                             multi_index[idim], idim);
+            if (check_and_adjust_index(&ind, shapevalue, idim) < 0) {
                 return NULL;
             }
 
@@ -2561,14 +2528,7 @@ PyArray_MultiIndexGetItem(PyArrayObject *self, npy_intp *multi_index)
             npy_intp shapevalue = shape[idim];
             npy_intp ind = multi_index[idim];
 
-            if (ind < 0) {
-                ind += shapevalue;
-            }
-
-            if (ind < 0 || ind >= shapevalue) {
-                PyErr_Format(PyExc_IndexError,
-                             "index %"NPY_INTP_FMT" out of bounds in dimension %d",
-                             multi_index[idim], idim);
+            if (check_and_adjust_index(&ind, shapevalue, idim) < 0) {
                 return NULL;
             }
 
@@ -2611,14 +2571,7 @@ PyArray_MultiIndexSetItem(PyArrayObject *self, npy_intp *multi_index,
             npy_intp shapevalue = shape[idim];
             npy_intp ind = multi_index[idim];
 
-            if (ind < 0) {
-                ind += shapevalue;
-            }
-
-            if (ind < 0 || ind >= shapevalue) {
-                PyErr_Format(PyExc_IndexError,
-                             "index %"NPY_INTP_FMT" out of bounds in dimension %d",
-                             multi_index[idim], idim);
+            if (check_and_adjust_index(&ind, shapevalue, idim) < 0) {
                 return -1;
             }
 
@@ -2655,14 +2608,7 @@ PyArray_MultiIndexSetItem(PyArrayObject *self, npy_intp *multi_index,
             npy_intp shapevalue = shape[idim];
             npy_intp ind = multi_index[idim];
 
-            if (ind < 0) {
-                ind += shapevalue;
-            }
-
-            if (ind < 0 || ind >= shapevalue) {
-                PyErr_Format(PyExc_IndexError,
-                             "index %"NPY_INTP_FMT" out of bounds in dimension %d",
-                             multi_index[idim], idim);
+            if (check_and_adjust_index(&ind, shapevalue, idim) < 0) {
                 return -1;
             }
 
diff --git a/numpy/core/src/multiarray/iterators.c b/numpy/core/src/multiarray/iterators.c
index e4bc1a336..1cc932ad9 100644
--- a/numpy/core/src/multiarray/iterators.c
+++ b/numpy/core/src/multiarray/iterators.c
@@ -31,7 +31,8 @@ slice_coerce_index(PyObject *o, npy_intp *v);
  */
 NPY_NO_EXPORT npy_intp
 parse_index_entry(PyObject *op, npy_intp *step_size,
-                    npy_intp *n_steps, npy_intp max)
+                  npy_intp *n_steps, npy_intp max,
+                  int axis, int check_index)
 {
     npy_intp i;
 
@@ -69,13 +70,10 @@ parse_index_entry(PyObject *op, npy_intp *step_size,
         }
         *n_steps = SINGLE_INDEX;
         *step_size = 0;
-        if (i < 0) {
-            i += max;
-        }
-        if (i >= max || i < 0) {
-            /* TODO: should report out-of-range indices with axis */
-            PyErr_SetString(PyExc_IndexError, "invalid index");
+        if (check_index) {
+            if (check_and_adjust_index(&i, max, axis) < 0) {
             goto fail;
+            }
         }
     }
     return i;
@@ -135,8 +133,9 @@ parse_index(PyArrayObject *self, PyObject *op,
             }
         }
         start = parse_index_entry(op1, &step_size, &n_steps,
-                               nd_old < PyArray_NDIM(self) ?
-                               PyArray_DIMS(self)[nd_old] : 0);
+                                  nd_old < PyArray_NDIM(self) ?
+                                  PyArray_DIMS(self)[nd_old] : 0,
+                                  nd_old, nd_old < PyArray_NDIM(self));
         Py_DECREF(op1);
         if (start == -1) {
             break;
@@ -718,14 +717,7 @@ iter_subscript_int(PyArrayIterObject *self, PyArrayObject *ind)
     itemsize = PyArray_DESCR(self->ao)->elsize;
     if (PyArray_NDIM(ind) == 0) {
         num = *((npy_intp *)PyArray_DATA(ind));
-        if (num < 0) {
-            num += self->size;
-        }
-        if (num < 0 || num >= self->size) {
-            PyErr_Format(PyExc_IndexError,
-                         "index %"NPY_INTP_FMT" out of bounds"   \
-                         " 0<=index<%"NPY_INTP_FMT,
-                         num, self->size);
+        if (check_and_adjust_index(&num, self->size, -1) < 0) {
             PyArray_ITER_RESET(self);
             return NULL;
         }
@@ -759,14 +751,7 @@ iter_subscript_int(PyArrayIterObject *self, PyArrayObject *ind)
     swap = (PyArray_ISNOTSWAPPED(ret) != PyArray_ISNOTSWAPPED(self->ao));
     while (counter--) {
         num = *((npy_intp *)(ind_it->dataptr));
-        if (num < 0) {
-            num += self->size;
-        }
-        if (num < 0 || num >= self->size) {
-            PyErr_Format(PyExc_IndexError,
-                         "index %"NPY_INTP_FMT" out of bounds" \
-                         " 0<=index<%"NPY_INTP_FMT,
-                         num, self->size);
+        if (check_and_adjust_index(&num, self->size, -1) < 0) {
             Py_DECREF(ind_it);
             Py_DECREF(ret);
             PyArray_ITER_RESET(self);
@@ -842,7 +827,7 @@ iter_subscript(PyArrayIterObject *self, PyObject *ind)
     /* Check for Integer or Slice */
     if (PyLong_Check(ind) || PyInt_Check(ind) || PySlice_Check(ind)) {
         start = parse_index_entry(ind, &step_size, &n_steps,
-                               self->size);
+                                  self->size, 0, 1);
         if (start == -1) {
             goto fail;
         }
@@ -1001,14 +986,7 @@ iter_ass_sub_int(PyArrayIterObject *self, PyArrayObject *ind,
     counter = ind_it->size;
     while (counter--) {
         num = *((npy_intp *)(ind_it->dataptr));
-        if (num < 0) {
-            num += self->size;
-        }
-        if ((num < 0) || (num >= self->size)) {
-            PyErr_Format(PyExc_IndexError,
-                         "index %"NPY_INTP_FMT" out of bounds"           \
-                         " 0<=index<%"NPY_INTP_FMT, num,
-                         self->size);
+        if (check_and_adjust_index(&num, self->size, -1) < 0) {
             Py_DECREF(ind_it);
             return -1;
         }
@@ -1119,7 +1097,7 @@ iter_ass_subscript(PyArrayIterObject *self, PyObject *ind, PyObject *val)
 
     /* Check Slice */
     if (PySlice_Check(ind)) {
-        start = parse_index_entry(ind, &step_size, &n_steps, self->size);
+        start = parse_index_entry(ind, &step_size, &n_steps, self->size, 0, 0);
         if (start == -1) {
             goto finish;
         }
diff --git a/numpy/core/src/multiarray/mapping.c b/numpy/core/src/multiarray/mapping.c
index 779769e23..821697f1a 100644
--- a/numpy/core/src/multiarray/mapping.c
+++ b/numpy/core/src/multiarray/mapping.c
@@ -57,15 +57,9 @@ array_big_item(PyArrayObject *self, npy_intp i)
 
     /* Bounds check and get the data pointer */
     dim0 = PyArray_DIM(self, 0);
-    if (i < -dim0 || i >= dim0) {
-        PyErr_Format(PyExc_IndexError,
-                     "index %"NPY_INTP_FMT" out of bounds in dimension 0",
-                     i);
+    if (check_and_adjust_index(&i, dim0, 0) < 0) {
         return NULL;
     }
-    if (i < 0) {
-        i += dim0;
-    }
     item = PyArray_DATA(self) + i * PyArray_STRIDE(self, 0);
 
     /* Create the view array */
@@ -123,15 +117,9 @@ array_item_nice(PyArrayObject *self, Py_ssize_t i)
 
         /* Bounds check and get the data pointer */
         dim0 = PyArray_DIM(self, 0);
-        if (i < -dim0 || i >= dim0) {
-            PyErr_Format(PyExc_IndexError,
-                         "index %"NPY_INTP_FMT" out of bounds in dimension 0",
-                         i);
+        if (check_and_adjust_index(&i, dim0, 0) < 0) {
             return NULL;
         }
-        if (i < 0) {
-            i += dim0;
-        }
         item = PyArray_DATA(self) + i * PyArray_STRIDE(self, 0);
 
         if (PyArray_HASMASKNA(self)) {
@@ -206,15 +194,9 @@ array_ass_big_item(PyArrayObject *self, npy_intp i, PyObject *v)
 
     /* Bounds check and get the data pointer */
     dim0 = PyArray_DIM(self, 0);
-    if (i < -dim0 || i >= dim0) {
-        PyErr_Format(PyExc_IndexError,
-                     "index %"NPY_INTP_FMT" out of bounds in dimension 0",
-                     i);
+    if (check_and_adjust_index(&i, dim0, 0) < 0) {
         return -1;
     }
-    if (i < 0) {
-        i += dim0;
-    }
     item = PyArray_DATA(self) + i * PyArray_STRIDE(self, 0);
 
     return PyArray_DESCR(self)->f->setitem(v, item, self);
@@ -1610,19 +1592,10 @@ array_ass_sub(PyArrayObject *self, PyObject *ind, PyObject *op)
         if (!PyArray_HASMASKNA(self)) {
             for (idim = 0; idim < ndim; idim++) {
                 npy_intp v = vals[idim];
-                if (v < 0) {
-                    v += shape[idim];
-                }
-                if (v < 0 || v >= shape[idim]) {
-                    PyErr_Format(PyExc_IndexError,
-                                 "index (%"NPY_INTP_FMT") out of range "\
-                                 "(0<=index<%"NPY_INTP_FMT") in dimension %d",
-                                 vals[idim], PyArray_DIMS(self)[idim], idim);
+                if (check_and_adjust_index(&v, shape[idim], idim) < 0) {
                     return -1;
                 }
-                else {
-                    item += v * strides[idim];
-                }
+                item += v * strides[idim];
             }
             return PyArray_DESCR(self)->f->setitem(op, item, self);
         }
@@ -1633,20 +1606,11 @@ array_ass_sub(PyArrayObject *self, PyObject *ind, PyObject *op)
 
             for (idim = 0; idim < ndim; idim++) {
                 npy_intp v = vals[idim];
-                if (v < 0) {
-                    v += shape[idim];
-                }
-                if (v < 0 || v >= shape[idim]) {
-                    PyErr_Format(PyExc_IndexError,
-                                 "index (%"NPY_INTP_FMT") out of range "\
-                                 "(0<=index<%"NPY_INTP_FMT") in dimension %d",
-                                 vals[idim], PyArray_DIMS(self)[idim], idim);
+                if (check_and_adjust_index(&v, shape[idim], idim) < 0) {
                     return -1;
                 }
-                else {
-                    item += v * strides[idim];
-                    maskna_item += v * maskna_strides[idim];
-                }
+                item += v * strides[idim];
+                maskna_item += v * maskna_strides[idim];
             }
             na = NpyNA_FromObject(op, 1);
             if (na == NULL) {
@@ -1768,19 +1732,10 @@ array_subscript_nice(PyArrayObject *self, PyObject *op)
         if (!PyArray_HASMASKNA(self)) {
             for (idim = 0; idim < ndim; idim++) {
                 npy_intp v = vals[idim];
-                if (v < 0) {
-                    v += shape[idim];
-                }
-                if (v < 0 || v >= shape[idim]) {
-                    PyErr_Format(PyExc_IndexError,
-                                 "index (%"NPY_INTP_FMT") out of range "\
-                                 "(0<=index<%"NPY_INTP_FMT") in dimension %d",
-                                 vals[idim], PyArray_DIMS(self)[idim], idim);
+                if (check_and_adjust_index(&v, shape[idim], idim) < 0) { 
                     return NULL;
                 }
-                else {
-                    item += v * strides[idim];
-                }
+                item += v * strides[idim];
             }
             return PyArray_Scalar(item, PyArray_DESCR(self), (PyObject *)self);
         }
@@ -1790,20 +1745,11 @@ array_subscript_nice(PyArrayObject *self, PyObject *op)
 
             for (idim = 0; idim < ndim; idim++) {
                 npy_intp v = vals[idim];
-                if (v < 0) {
-                    v += shape[idim];
-                }
-                if (v < 0 || v >= shape[idim]) {
-                    PyErr_Format(PyExc_IndexError,
-                                 "index (%"NPY_INTP_FMT") out of range "\
-                                 "(0<=index<%"NPY_INTP_FMT") in dimension %d",
-                                 vals[idim], PyArray_DIMS(self)[idim], idim);
+                if (check_and_adjust_index(&v, shape[idim], idim) < 0) {
                     return NULL;
                 }
-                else {
-                    item += v * strides[idim];
-                    maskna_item += v * maskna_strides[idim];
-                }
+                item += v * strides[idim];
+                maskna_item += v * maskna_strides[idim];
             }
             if (NpyMaskValue_IsExposed((npy_mask)*maskna_item)) {
                 return PyArray_Scalar(item, PyArray_DESCR(self),
@@ -2141,7 +2087,7 @@ PyArray_MapIterBind(PyArrayMapIterObject *mit, PyArrayObject *arr)
 
     subnd = PyArray_NDIM(arr) - mit->numiter;
     if (subnd < 0) {
-        PyErr_SetString(PyExc_ValueError,
+        PyErr_SetString(PyExc_IndexError,
                         "too many indices for array");
         return;
     }
@@ -2270,14 +2216,7 @@ PyArray_MapIterBind(PyArrayMapIterObject *mit, PyArrayObject *arr)
         while (it->index < it->size) {
             indptr = ((npy_intp *)it->dataptr);
             indval = *indptr;
-            if (indval < 0) {
-                indval += dimsize;
-            }
-            if (indval < 0 || indval >= dimsize) {
-                PyErr_Format(PyExc_IndexError,
-                             "index (%"NPY_INTP_FMT") out of range "\
-                             "(0<=index<%"NPY_INTP_FMT") in dimension %d",
-                             indval, (dimsize-1), mit->iteraxes[i]);
+            if (check_and_adjust_index(&indval, dimsize, mit->iteraxes[i]) < 0) {
                 goto fail;
             }
             PyArray_ITER_NEXT(it);
diff --git a/numpy/core/src/multiarray/methods.c b/numpy/core/src/multiarray/methods.c
index 8129a7021..29035ad1e 100644
--- a/numpy/core/src/multiarray/methods.c
+++ b/numpy/core/src/multiarray/methods.c
@@ -697,14 +697,7 @@ array_toscalar(PyArrayObject *self, PyObject *args)
             return NULL;
         }
 
-        /* Negative indexing */
-        if (value < 0) {
-            value += size;
-        }
-
-        if (value < 0 || value >= size) {
-            PyErr_SetString(PyExc_ValueError,
-                    "index out of bounds");
+        if (check_and_adjust_index(&value, size, -1) < 0) {
             return NULL;
         }
 
@@ -783,14 +776,7 @@ array_setscalar(PyArrayObject *self, PyObject *args)
             return NULL;
         }
 
-        /* Negative indexing */
-        if (value < 0) {
-            value += size;
-        }
-
-        if (value < 0 || value >= size) {
-            PyErr_SetString(PyExc_ValueError,
-                    "index out of bounds");
+        if (check_and_adjust_index(&value, size, -1) < 0) {
             return NULL;
         }
 
diff --git a/numpy/core/src/multiarray/multiarraymodule.c b/numpy/core/src/multiarray/multiarraymodule.c
index 7a657d8b9..75929198d 100644
--- a/numpy/core/src/multiarray/multiarraymodule.c
+++ b/numpy/core/src/multiarray/multiarraymodule.c
@@ -320,6 +320,7 @@ PyArray_ConcatenateArrays(int narrays, PyArrayObject **arrays, int axis)
     PyArrayObject *ret = NULL;
     PyArrayObject_fields *sliding_view = NULL;
     int has_maskna;
+    int orig_axis = axis;
 
     if (narrays <= 0) {
         PyErr_SetString(PyExc_ValueError,
@@ -342,7 +343,7 @@ PyArray_ConcatenateArrays(int narrays, PyArrayObject **arrays, int axis)
     }
     if (axis < 0 || axis >= ndim) {
         PyErr_Format(PyExc_IndexError,
-                        "axis %d out of bounds [0, %d)", axis, ndim);
+                     "axis %d out of bounds [0, %d)", orig_axis, ndim);
         return NULL;
     }