# HG changeset patch
# User Simon Sapin <simon.sapin@octobus.net>
# Date 2021-01-25 11:31:40
# Node ID e61c2dc6e1c2fbbbc0a1402adfccbd50c0485f63
# Parent  5893706af3decde7b3a63ec4b4fa188d02cddecb

rust: Exclude empty node prefixes

We presumably don’t want `--rev ""` to select every single revision,
even though the empty string is a prefix of all strings.

Differential Revision: https://phab.mercurial-scm.org/D9862

diff --git a/rust/hg-core/src/revlog/node.rs b/rust/hg-core/src/revlog/node.rs
--- a/rust/hg-core/src/revlog/node.rs
+++ b/rust/hg-core/src/revlog/node.rs
@@ -160,7 +160,7 @@ impl NodePrefix {
     pub fn from_hex(hex: impl AsRef<[u8]>) -> Result<Self, FromHexError> {
         let hex = hex.as_ref();
         let len = hex.len();
-        if len > NODE_NYBBLES_LENGTH {
+        if len > NODE_NYBBLES_LENGTH || len == 0 {
             return Err(FromHexError);
         }
 
@@ -201,10 +201,6 @@ impl<'a> NodePrefixRef<'a> {
         }
     }
 
-    pub fn is_empty(&self) -> bool {
-        self.len() == 0
-    }
-
     pub fn is_prefix_of(&self, node: &Node) -> bool {
         if self.is_odd {
             let buf = self.buf;