Polishing.

Author: serhiy-storchaka

Lib/test/test_binascii.py

@@ -202,16 +202,16 @@ def assertNonBase64Data(data, expected, ignorechars):
         assertNonBase64Data(b'a\nb==', b'i', ignorechars=bytearray(b'\n'))
         assertNonBase64Data(b'a\nb==', b'i', ignorechars=memoryview(b'\n'))
 
-        # Same byte in the bit cache: '\r' >> 3 == '\n' >> 3.
+        # Same cell in the cache: '\r' >> 3 == '\n' >> 3.
         data = self.type2test(b'\r\n')
         with self.assertRaises(binascii.Error):
             binascii.a2b_base64(data, ignorechars=b'\r')
         self.assertEqual(binascii.a2b_base64(data, ignorechars=b'\r\n'), b'')
-        # Same mask in the bit cache: ':' & 7 == '\n' & 7.
-        data = self.type2test(b':\n')
+        # Same bit mask in the cache: '*' & 31 == '\n' & 31.
+        data = self.type2test(b'*\n')
         with self.assertRaises(binascii.Error):
-            binascii.a2b_base64(data, ignorechars=b':')
-        self.assertEqual(binascii.a2b_base64(data, ignorechars=b':\n'), b'')
+            binascii.a2b_base64(data, ignorechars=b'*')
+        self.assertEqual(binascii.a2b_base64(data, ignorechars=b'*\n'), b'')
 
         data = self.type2test(b'a\nb==')
         with self.assertRaises(TypeError):

Modules/binascii.c

@@ -469,11 +469,13 @@ binascii_b2a_uu_impl(PyObject *module, Py_buffer *data, int backtick)
     return PyBytesWriter_FinishWithPointer(writer, ascii_data);
 }
 
+typedef unsigned char ignorecache_t[32];
 
 static int
-ignorechar(unsigned char c, Py_buffer *ignorechars, char ignorecache[32])
+ignorechar(unsigned char c, const Py_buffer *ignorechars,
+           ignorecache_t ignorecache)
 {
-    if (ignorechars->buf == NULL) {
+    if (ignorechars == NULL) {
         return 0;
     }
     if (ignorecache[c >> 3] & (1 << (c & 7))) {
@@ -517,8 +519,11 @@ binascii_a2b_base64_impl(PyObject *module, Py_buffer *data, int strict_mode,
     if (strict_mode == -1) {
         strict_mode = (ignorechars->buf != NULL);
     }
-    char ignorecache[32];
-    if (strict_mode && ignorechars->buf != NULL) {
+    if (!strict_mode || ignorechars->buf == NULL || ignorechars->len == 0) {
+        ignorechars = NULL;
+    }
+    ignorecache_t ignorecache;
+    if (ignorechars != NULL) {
         memset(ignorecache, 0, sizeof(ignorecache));
     }