Use case-insensitive comparison when checking \N escapes

Author: SnoopJ

Misc/NEWS.d/next/Core and Builtins/2023-07-26-00-03-00.gh-issue-80667.N7Dh8B.rst

@@ -0,0 +1,2 @@
+Literals using the ``\N{name}`` escape syntax can now construct CJK
+ideographs and Hangul syllables using case-insensitive names.

Modules/unicodedata.c

@@ -1181,7 +1181,7 @@ find_syllable(const char *str, int *len, int *pos, int count, int column)
         len1 = Py_SAFE_DOWNCAST(strlen(s), size_t, int);
         if (len1 <= *len)
             continue;
-        if (strncmp(str, s, len1) == 0) {
+        if (PyOS_strnicmp(str, s, len1) == 0) {
             *len = len1;
             *pos = i;
         }
@@ -1219,7 +1219,7 @@ _getcode(PyObject* self,
     unsigned int i, incr;
 
     /* Check for hangul syllables. */
-    if (strncmp(name, "HANGUL SYLLABLE ", 16) == 0) {
+    if (PyOS_strnicmp(name, "HANGUL SYLLABLE ", 16) == 0) {
         int len, L = -1, V = -1, T = -1;
         const char *pos = name + 16;
         find_syllable(pos, &len, &L, LCount, 0);
@@ -1237,7 +1237,7 @@ _getcode(PyObject* self,
     }
 
     /* Check for unified ideographs. */
-    if (strncmp(name, "CJK UNIFIED IDEOGRAPH-", 22) == 0) {
+    if (PyOS_strnicmp(name, "CJK UNIFIED IDEOGRAPH-", 22) == 0) {
         /* Four or five hexdigits must follow. */
         v = 0;
         name += 22;