commit f669581a9527afb0d2325f9845a86715c0ba365d
author Serhiy Storchaka <storchaka@gmail.com> Tue Sep 17 09:20:56 2019 +0300
committer GitHub <noreply@github.com> Tue Sep 17 09:20:56 2019 +0300
tree 964f3dd5596e65d33e5349497025b44e070f33b9
parent dfd34a9cd58e8150c324190f746de919e140abe8

bpo-38185: Fixed case-insensitive string comparison in sqlite3.Row indexing. (GH-16190)

Modules/_sqlite/row.c

diff --git a/Modules/_sqlite/row.c b/Modules/_sqlite/row.c
index 758518a..4b47108 100644
--- a/Modules/_sqlite/row.c
+++ b/Modules/_sqlite/row.c
@@ -76,16 +76,38 @@
    return item;
 }
 
+static int
+equal_ignore_case(PyObject *left, PyObject *right)
+{
+    int eq = PyObject_RichCompareBool(left, right, Py_EQ);
+    if (eq) { /* equal or error */
+        return eq;
+    }
+    if (!PyUnicode_Check(left) || !PyUnicode_Check(right)) {
+        return 0;
+    }
+    if (!PyUnicode_IS_ASCII(left) || !PyUnicode_IS_ASCII(right)) {
+        return 0;
+    }
+
+    Py_ssize_t len = PyUnicode_GET_LENGTH(left);
+    if (PyUnicode_GET_LENGTH(right) != len) {
+        return 0;
+    }
+    const Py_UCS1 *p1 = PyUnicode_1BYTE_DATA(left);
+    const Py_UCS1 *p2 = PyUnicode_1BYTE_DATA(right);
+    for (; len; len--, p1++, p2++) {
+        if (Py_TOLOWER(*p1) != Py_TOLOWER(*p2)) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
 PyObject* pysqlite_row_subscript(pysqlite_Row* self, PyObject* idx)
 {
     Py_ssize_t _idx;
-    const char *key;
     Py_ssize_t nitems, i;
-    const char *compare_key;
-
-    const char *p1;
-    const char *p2;
-
     PyObject* item;
 
     if (PyLong_Check(idx)) {
@@ -98,44 +120,22 @@
         Py_XINCREF(item);
         return item;
     } else if (PyUnicode_Check(idx)) {
-        key = PyUnicode_AsUTF8(idx);
-        if (key == NULL)
-            return NULL;
-
         nitems = PyTuple_Size(self->description);
 
         for (i = 0; i < nitems; i++) {
             PyObject *obj;
             obj = PyTuple_GET_ITEM(self->description, i);
             obj = PyTuple_GET_ITEM(obj, 0);
-            compare_key = PyUnicode_AsUTF8(obj);
-            if (!compare_key) {
+            int eq = equal_ignore_case(idx, obj);
+            if (eq < 0) {
                 return NULL;
             }
-
-            p1 = key;
-            p2 = compare_key;
-
-            while (1) {
-                if ((*p1 == (char)0) || (*p2 == (char)0)) {
-                    break;
-                }
-
-                if ((*p1 | 0x20) != (*p2 | 0x20)) {
-                    break;
-                }
-
-                p1++;
-                p2++;
-            }
-
-            if ((*p1 == (char)0) && (*p2 == (char)0)) {
+            if (eq) {
                 /* found item */
                 item = PyTuple_GetItem(self->data, i);
                 Py_INCREF(item);
                 return item;
             }
-
         }
 
         PyErr_SetString(PyExc_IndexError, "No item with that key");