Ported tests all pass

kittens/transfer/algorithm.c

@@ -339,10 +339,16 @@ apply_op(Patcher *self, Operation op, PyObject *read, PyObject *write) {
             if (!wret) return false;
         } return true;
         case OpHash: {
-            uint8_t expected[64];
+            uint8_t actual[64];
             if (op.data.len != self->rsync.checksummer.hash_size) { PyErr_SetString(RsyncError, "checksum digest not the correct size"); return false; }
-            self->rsync.checksummer.digest(self->rsync.checksummer.state, expected);
-            if (memcmp(expected, op.data.buf, op.data.len) != 0) { PyErr_SetString(RsyncError, "checksum does not match, this usually happens because one of the involved files was altered while the operation was in progress"); return false; }
+            self->rsync.checksummer.digest(self->rsync.checksummer.state, actual);
+            if (memcmp(actual, op.data.buf, self->rsync.checksummer.hash_size) != 0) {
+                DECREF_AFTER_FUNCTION PyObject *b1 = PyBytes_FromStringAndSize((char*)actual, self->rsync.checksummer.hash_size);
+                DECREF_AFTER_FUNCTION PyObject *h1 = PyObject_CallMethod(b1, "hex", NULL);
+                DECREF_AFTER_FUNCTION PyObject *b2 = PyBytes_FromStringAndSize((char*)op.data.buf, self->rsync.checksummer.hash_size);
+                DECREF_AFTER_FUNCTION PyObject *h2 = PyObject_CallMethod(b2, "hex", NULL);
+                PyErr_Format(RsyncError, "Failed to verify overall file checksum actual: %S != expected: %S, this usually happens because one of the involved files was altered while the operation was in progress.", h1, h2);
+                return false; }
         } return true;
     }
     PyErr_SetString(RsyncError, "Unknown operation type");
@@ -504,7 +510,7 @@ static size_t
 parse_signature_block(Differ *self, uint8_t *data, size_t len) {
     if (len < 20) return 0;
     int weak_hash = le32dec(data + 8);
-    SignatureMap *sm;
+    SignatureMap *sm = NULL;
     HASH_FIND_INT(self->signature_map, &weak_hash, sm);
     if (sm == NULL) {
         sm = calloc(1, sizeof(SignatureMap));
@@ -713,11 +719,12 @@ read_next(Differ *self) {
 		self->window.sz = self->rsync.block_size;
         rolling_checksum_full(&self->rc, self->buf.data + self->window.pos, self->window.sz);
     }
-    SignatureMap *sm;
+    SignatureMap *sm = NULL;
     int weak_hash = self->rc.val;
     uint64_t block_index = 0;
     HASH_FIND_INT(self->signature_map, &weak_hash, sm);
     if (sm != NULL && find_strong_hash(sm, self->rsync.hasher.oneshot64(self->buf.data + self->window.pos, self->window.sz), &block_index)) {
+        if (!send_data(self)) return false;
         if (!enqueue(self, (Operation){.type=OpBlock, .block_index=block_index})) return false;
 		self->window.pos += self->window.sz;
 		self->data.pos = self->window.pos;

kitty_tests/file_transmission.py

@@ -78,10 +78,10 @@ def patch_data(data, *patches):
 def run_roundtrip_test(self: 'TestFileTransmission', src_data, changed, num_of_patches, total_patch_size):
     buf = memoryview(bytearray(30))
     signature = bytearray(0)
-    p = Patcher(len(src_data))
+    p = Patcher(len(changed))
     n = p.signature_header(buf)
     signature.extend(buf[:n])
-    src = memoryview(src_data)
+    src = memoryview(changed)
     bs = p.block_size
     while src:
         n = p.sign_block(src[:bs], buf)
@@ -93,6 +93,7 @@ def run_roundtrip_test(self: 'TestFileTransmission', src_data, changed, num_of_p
         d.add_signature_data(src[:13])
         src = src[13:]
     d.finish_signature_data()
+    del src, signature
     src = memoryview(src_data)
     delta = bytearray(0)
     def read_into(b):
@@ -107,6 +108,7 @@ def run_roundtrip_test(self: 'TestFileTransmission', src_data, changed, num_of_p
     while d.next_op(read_into, write_delta):
         pass
     delta = memoryview(delta)
+    del src
 
     def read_at(pos, output) -> int:
         b = changed[pos:]
@@ -119,14 +121,19 @@ def run_roundtrip_test(self: 'TestFileTransmission', src_data, changed, num_of_p
     def write_changes(b):
         output.extend(b)
 
+    def debug_msg():
+        return f'\n\nsrc:\n{src_data.decode()}\nchanged:\n{changed.decode()}\noutput:\n{output.decode()}'
+    try:
         while delta:
             p.apply_delta_data(delta[:11], read_at, write_changes)
             delta = delta[11:]
         p.finish_delta_data()
-    self.assertEqual(src_data, bytes(output), f'\n\nsrc:\n{src_data.decode()}\nchanged:\n{changed.decode()}\noutput:\n{output.decode()}')
+    except Exception as err:
+        self.fail(f'{err}\n{debug_msg()}')
+    self.assertEqual(src_data, bytes(output), debug_msg())
     limit = 2 * (p.block_size * num_of_patches)
     if limit > -1:
-        self.assertLess(
+        self.assertLessEqual(
             p.total_data_in_delta, limit, f'Unexpectedly poor delta performance: {total_patch_size=} {p.total_data_in_delta=} {limit=}')
 
 

tools/rsync/algorithm.go

@@ -11,6 +11,7 @@ package rsync
 import (
 	"bytes"
 	"encoding/binary"
+	"encoding/hex"
 	"fmt"
 	"hash"
 	"io"
@@ -314,9 +315,9 @@ func (r *rsync) ApplyDelta(alignedTarget io.Writer, target io.ReadSeeker, op Ope
 			return err
 		}
 	case OpHash:
-		expected := r.checksummer.Sum(nil)
-		if !bytes.Equal(expected, op.Data) {
-			return fmt.Errorf("Failed to verify overall file checksum. This usually happens if some data was corrupted in transit or one of the involved files was altered while the transfer was in progress.")
+		actual := r.checksummer.Sum(nil)
+		if !bytes.Equal(actual, op.Data) {
+			return fmt.Errorf("Failed to verify overall file checksum actual: %s != expected: %s. This usually happens if some data was corrupted in transit or one of the involved files was altered while the transfer was in progress.", hex.EncodeToString(actual), hex.EncodeToString(op.Data))
 		}
 	}
 	return nil

tools/rsync/api_test.go

@@ -85,7 +85,7 @@ func run_roundtrip_test(t *testing.T, src_data, changed []byte, num_of_patches,
 
 	// Now try with serialization
 	using_serialization = true
-	p = NewPatcher(int64(len(src_data)))
+	p = NewPatcher(int64(len(changed)))
 	signature_of_changed := bytes.Buffer{}
 	ss_it := p.CreateSignatureIterator(bytes.NewReader(changed), &signature_of_changed)
 	var err error