filter: require an extra "+" before data

This disambiguates it from control commands

diff --git a/extensions/filter.c b/extensions/filter.c
index 1cb278294748aabf9399ebacc2940f957cc29e27..cf7907c24e2da915eea11f388e9e9fddf5ba87e3 100644 (file)
--- a/extensions/filter.c
+++ b/extensions/filter.c
@@ -196,6 +196,13 @@ setfilter(const char *check, const char *data, const char **error)
                return 0;
        }
 
+       if (*data != '+') {
+               if (error) *error = "unknown command or data doesn't start with +";
+               return -1;
+       }
+
+       data += 1;
+
        if (state == FILTER_FILLING) {
                int dl;
                unsigned char *d = rb_base64_decode(data, strlen(data), &dl);