From: Matt Joiner <anacrolix@gmail.com>
Date: Fri, 7 Jan 2022 08:11:37 +0000 (+1100)
Subject: bencode: Support decoding "" as dict key
X-Git-Tag: v1.41.0~28
X-Git-Url: http://www.git.stargrave.org/?a=commitdiff_plain;h=726eec2f8ddc35b40ad674ba0c5ed6944a576f72;p=btrtrc.git

bencode: Support decoding "" as dict key
---

diff --git a/bencode/decode.go b/bencode/decode.go
index 1007db90..e72a12d5 100644
--- a/bencode/decode.go
+++ b/bencode/decode.go
@@ -690,7 +690,8 @@ func (d *Decoder) parseStringInterface() string {
 
 func (d *Decoder) parseDictInterface() interface{} {
 	dict := make(map[string]interface{})
-	lastKey := ""
+	var lastKey string
+	lastKeyOk := false
 	for {
 		start := d.Offset
 		keyi, ok := d.parseValueInterface()
@@ -705,7 +706,7 @@ func (d *Decoder) parseDictInterface() interface{} {
 				What:   errors.New("non-string key in a dict"),
 			})
 		}
-		if key <= lastKey {
+		if lastKeyOk && key <= lastKey {
 			d.throwSyntaxError(start, fmt.Errorf("dict keys unsorted: %q <= %q", key, lastKey))
 		}
 		start = d.Offset
@@ -715,6 +716,7 @@ func (d *Decoder) parseDictInterface() interface{} {
 		}
 
 		lastKey = key
+		lastKeyOk = true
 		dict[key] = valuei
 	}
 	return dict
diff --git a/bencode/decode_test.go b/bencode/decode_test.go
index 8cb972f8..eaf9e71e 100644
--- a/bencode/decode_test.go
+++ b/bencode/decode_test.go
@@ -40,6 +40,7 @@ var random_decode_tests = []random_decode_test{
 		"v": "TR%=",
 		"y": "r",
 	}},
+	{"d0:i420ee", map[string]interface{}{"": int64(420)}},
 }
 
 func TestRandomDecode(t *testing.T) {