lib/model: Handle (?d) deletes of directories (fixes #3164)

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3170

lib/ignore/ignore.go

@@ -246,8 +246,7 @@ func parseIgnoreFile(fd io.Reader, currentFile string, seen map[string]bool) ([]
 
 	addPattern := func(line string) error {
 		pattern := Pattern{
-			pattern: line,
-			result:  defaultResult,
+			result: defaultResult,
 		}
 
 		// Allow prefixes to be specified in any order, but only once.
@@ -275,6 +274,8 @@ func parseIgnoreFile(fd io.Reader, currentFile string, seen map[string]bool) ([]
 			line = strings.ToLower(line)
 		}
 
+		pattern.pattern = line
+
 		var err error
 		if strings.HasPrefix(line, "/") {
 			// Pattern is rooted in the current dir only