Merge remote-tracking branch 'github/pull/1227' into msimacek/GR-80787-GitHub_PRs_1227-1232

Author: msimacek

graalpython/com.oracle.graal.python.test/src/tests/test_bytes.py

@@ -89,6 +89,16 @@ def __bytes__(self):
     assert_raises(TypeError, bytes, errors="strict")
 
 
+def test_decode_empty_skips_codec_lookup():
+    assert str(b'', 'x') == ''
+    assert str(bytearray(), 'x', 'y') == ''
+    assert str(memoryview(b''), 'x') == ''
+    assert b''.decode('x') == ''
+    assert bytearray().decode('x') == ''
+    assert_raises(LookupError, str, b'a', 'x')
+    assert_raises(TypeError, str, 1, 'x')
+
+
 def test_from_ssize():
     assert bytes(0) == b''
     assert bytes(1) == b'\x00'

graalpython/com.oracle.graal.python/src/com/oracle/graal/python/builtins/objects/bytes/BytesCommonBuiltins.java

@@ -203,9 +203,15 @@ protected ArgumentClinicProvider getArgumentClinic() {
         @Specialization
         static Object decode(VirtualFrame frame, Object self, TruffleString encoding, TruffleString errors,
                         @Bind Node inliningTarget,
+                        @Cached GetBytesStorage getBytesStorage,
+                        @Cached InlinedConditionProfile emptyStringProfile,
                         @Cached CodecsModuleBuiltins.DecodeNode decodeNode,
                         @Cached PyUnicodeCheckNode unicodeCheckNode,
                         @Cached PRaiseNode raiseNode) {
+            // like CPython's PyUnicode_FromEncodedObject: no codec lookup for empty input
+            if (emptyStringProfile.profile(inliningTarget, getBytesStorage.execute(inliningTarget, self).length() == 0)) {
+                return T_EMPTY_STRING;
+            }
             Object result = decodeNode.executeWithStrings(frame, self, encoding, errors);
             if (!unicodeCheckNode.execute(inliningTarget, result)) {
                 throw raiseNode.raise(inliningTarget, TypeError, DECODER_RETURNED_P_INSTEAD_OF_BYTES, encoding, result);