Fix delegation loop in Ballot example contract

fixes #1753

1 files changed, 8 insertions, 8 deletions

diff --git a/docs/solidity-by-example.rst b/docs/solidity-by-example.rst
index 915cfa76..7e08c6b4 100644
--- a/docs/solidity-by-example.rst
+++ b/docs/solidity-by-example.rst
@@ -106,6 +106,10 @@ of votes.
             if (sender.voted)
                 throw;
 
+            // Self-delegation is not allowed.
+            if (to == msg.sender)
+                throw;
+
             // Forward the delegation as long as
             // `to` also delegated.
             // In general, such loops are very dangerous,
@@ -114,16 +118,12 @@ of votes.
             // In this case, the delegation will not be executed,
             // but in other situations, such loops might
             // cause a contract to get "stuck" completely.
-            while (
-                voters[to].delegate != address(0) &&
-                voters[to].delegate != msg.sender
-            ) {
+            while (voters[to].delegate != address(0)) {
                 to = voters[to].delegate;
-            }
 
-            // We found a loop in the delegation, not allowed.
-            if (to == msg.sender) {
-                throw;
+                // We found a loop in the delegation, not allowed.
+                if (to == msg.sender) 
+                    throw;
             }
 
             // Since `sender` is a reference, this