Resolve UTF8 charset case-insensitively (#1195)

ek247 · web-flow · commit 7dead51f8605 · 2025-01-12T17:17:12.000+09:00
diff --git a/pymysql/charset.py b/pymysql/charset.py
@@ -45,9 +45,10 @@ def by_id(self, id):
         return self._by_id[id]
 
     def by_name(self, name):
+        name = name.lower()
         if name == "utf8":
             name = "utf8mb4"
-        return self._by_name.get(name.lower())
+        return self._by_name.get(name)
 
 
 _charsets = Charsets()
diff --git a/pymysql/tests/test_charset.py b/pymysql/tests/test_charset.py
@@ -21,5 +21,23 @@ def test_utf8():
     )
 
     # utf8 is alias of utf8mb4 since MySQL 8.0, and PyMySQL v1.1.
-    utf8 = pymysql.charset.charset_by_name("utf8")
-    assert utf8 == utf8mb4
+    lowercase_utf8 = pymysql.charset.charset_by_name("utf8")
+    assert lowercase_utf8 == utf8mb4
+
+    # Regardless of case, UTF8 (which is special cased) should resolve to the same thing
+    uppercase_utf8 = pymysql.charset.charset_by_name("UTF8")
+    mixedcase_utf8 = pymysql.charset.charset_by_name("UtF8")
+    assert uppercase_utf8 == lowercase_utf8
+    assert mixedcase_utf8 == lowercase_utf8
+
+def test_case_sensitivity():
+    lowercase_latin1 = pymysql.charset.charset_by_name("latin1")
+    assert lowercase_latin1 is not None
+
+    # lowercase and uppercase should resolve to the same charset
+    uppercase_latin1 = pymysql.charset.charset_by_name("LATIN1")
+    assert uppercase_latin1 == lowercase_latin1
+
+    # lowercase and mixed case should resolve to the same charset
+    mixedcase_latin1 = pymysql.charset.charset_by_name("LaTiN1")
+    assert mixedcase_latin1 == lowercase_latin1
