1 files changed, 26 insertions, 32 deletions

diff --git a/Modules/_sre.c b/Modules/_sre.c
index 21c41b5..5cea756 100644
--- a/Modules/_sre.c
+++ b/Modules/_sre.c
@@ -1899,15 +1899,7 @@ match_getslice_by_index(MatchObject* self, Py_ssize_t index, PyObject* def)
     void* ptr;
     Py_ssize_t i, j;
 
-    if (index < 0 || index >= self->groups) {
-        /* raise IndexError if we were given a bad group number */
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
-        return NULL;
-    }
-
+    assert(0 <= index && index < self->groups);
     index *= 2;
 
     if (self->string == Py_None || self->mark[index] < 0) {
@@ -1940,17 +1932,25 @@ match_getindex(MatchObject* self, PyObject* index)
         return 0;
 
     if (PyIndex_Check(index)) {
-        return PyNumber_AsSsize_t(index, NULL);
+        i = PyNumber_AsSsize_t(index, NULL);
     }
+    else {
+        i = -1;
 
-    i = -1;
-
-    if (self->pattern->groupindex) {
-        index = PyDict_GetItem(self->pattern->groupindex, index);
-        if (index && PyLong_Check(index)) {
-            i = PyLong_AsSsize_t(index);
+        if (self->pattern->groupindex) {
+            index = PyDict_GetItemWithError(self->pattern->groupindex, index);
+            if (index && PyLong_Check(index)) {
+                i = PyLong_AsSsize_t(index);
+            }
         }
     }
+    if (i < 0 || i >= self->groups) {
+        /* raise IndexError if we were given a bad group number */
+        if (!PyErr_Occurred()) {
+            PyErr_SetString(PyExc_IndexError, "no such group");
+        }
+        return -1;
+    }
 
     return i;
 }
@@ -1958,7 +1958,13 @@ match_getindex(MatchObject* self, PyObject* index)
 static PyObject*
 match_getslice(MatchObject* self, PyObject* index, PyObject* def)
 {
-    return match_getslice_by_index(self, match_getindex(self, index), def);
+    Py_ssize_t i = match_getindex(self, index);
+
+    if (i < 0) {
+        return NULL;
+    }
+
+    return match_getslice_by_index(self, i, def);
 }
 
 /*[clinic input]
@@ -2114,11 +2120,7 @@ _sre_SRE_Match_start_impl(MatchObject *self, PyObject *group)
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
+    if (index < 0) {
         return -1;
     }
 
@@ -2141,11 +2143,7 @@ _sre_SRE_Match_end_impl(MatchObject *self, PyObject *group)
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
+    if (index < 0) {
         return -1;
     }
 
@@ -2195,11 +2193,7 @@ _sre_SRE_Match_span_impl(MatchObject *self, PyObject *group)
 {
     Py_ssize_t index = match_getindex(self, group);
 
-    if (index < 0 || index >= self->groups) {
-        PyErr_SetString(
-            PyExc_IndexError,
-            "no such group"
-            );
+    if (index < 0) {
         return NULL;
     }