Selection: fail early if new() is called with no ranges.

1 files changed, 3 insertions, 1 deletions

diff --git a/helix-core/src/transaction.rs b/helix-core/src/transaction.rs
index 1f9e63aa..f25ee208 100644
--- a/helix-core/src/transaction.rs
+++ b/helix-core/src/transaction.rs
@@ -464,11 +464,13 @@ impl Transaction {
         I: IntoIterator<Item = Change> + ExactSizeIterator,
     {
         let len = doc.len_chars();
-        let acc = Vec::with_capacity(2 * changes.len() + 1);
+        let acc = Vec::with_capacity(2 * changes.len() + 1); // rough estimate
         let mut changeset = ChangeSet { changes: acc, len };
 
         // TODO: verify ranges are ordered and not overlapping or change will panic.
 
+        // TODO: test for (pos, pos, None) to factor out as nothing
+
         let mut last = 0;
         for (from, to, tendril) in changes {
             // Retain from last "to" to current "from"