Allow arbitrary bytes in the mime metadata key

kitty/clipboard.py

@@ -180,6 +180,18 @@ class ProtocolType(Enum):
     osc_5522 = 5522
 
 
+def encode_mime(x: str) -> str:
+    import base64
+    return base64.standard_b64encode(x.encode('utf-8')).decode('ascii')
+
+
+def decode_metadata_value(k: str, x: str) -> str:
+    if k == 'mime':
+        import base64
+        x = base64.standard_b64decode(x).decode('utf-8')
+    return x
+
+
 class ReadRequest(NamedTuple):
     is_primary_selection: bool = False
     mime_types: Tuple[str, ...] = ('text/plain',)
@@ -193,7 +205,7 @@ class ReadRequest(NamedTuple):
         if self.id:
             ans += f':id={self.id}'
         if mime:
-            ans += f':mime={mime}'
+            ans += f':mime={encode_mime(mime)}'
         a = ans.encode('ascii')
         if payload:
             import base64
@@ -318,7 +330,7 @@ class ClipboardRequestManager:
             except Exception:
                 log_error('Malformed OSC 5522: metadata is not key=value pairs')
                 return
-            m[k] = v
+            m[k] = decode_metadata_value(k, v)
         typ = m.get('type', '')
         if typ == 'read':
             payload = base64.standard_b64decode(epayload)

tools/cmd/clipboard/read.go

@@ -160,6 +160,23 @@ func (self *Output) assign_mime_type(available_mimes []string) (err error) {
 	return fmt.Errorf("The MIME type %s for %s not available on the clipboard", self.mime_type, self.arg)
 }
 
+func escape_metadata_value(k, x string) (ans string) {
+	if k == "mime" {
+		x = base64.StdEncoding.EncodeToString(utils.UnsafeStringToBytes(x))
+	}
+	return x
+}
+
+func unescape_metadata_value(k, x string) (ans string) {
+	if k == "mime" {
+		b, err := base64.StdEncoding.DecodeString(x)
+		if err == nil {
+			x = string(b)
+		}
+	}
+	return x
+}
+
 func encode_bytes(metadata map[string]string, payload []byte) string {
 	ans := strings.Builder{}
 	ans.Grow(2048)
@@ -172,7 +189,7 @@ func encode_bytes(metadata map[string]string, payload []byte) string {
 		}
 		ans.WriteString(k)
 		ans.WriteString("=")
-		ans.WriteString(v)
+		ans.WriteString(escape_metadata_value(k, v))
 	}
 	if len(payload) > 0 {
 		ans.WriteString(";")
@@ -217,7 +234,8 @@ func parse_escape_code(etype loop.EscapeCodeType, data []byte) (metadata map[str
 			if len(rp) == 2 {
 				v = string(rp[1])
 			}
-			metadata[string(rp[0])] = v
+			k := string(rp[0])
+			metadata[k] = unescape_metadata_value(k, v)
 		}
 	}