Corrections and some style.

docs/frequently-asked-questions.rst

@@ -665,7 +665,7 @@ What does the following strange check do in the Custom Token contract?
 
 ::
 
-    require(balanceOf[_to] + _value >= balanceOf[_to]);
+    require((balanceOf[_to] + _value) >= balanceOf[_to]);
 
 Integers in Solidity (and most other machine-related programming languages) are restricted to a certain range.
 For ``uint256``, this is ``0`` up to ``2**256 - 1``. If the result of some operation on those numbers

docs/security-considerations.rst

@@ -137,7 +137,8 @@ Sending and Receiving Ether
      depth, they can force the transfer to fail; take this possibility into account or use ``send`` and make sure to always check its return value. Better yet,
      write your contract using a pattern where the recipient can withdraw Ether instead.
   3. Sending Ether can also fail because the execution of the recipient contract
-     requires more than the allotted amount of gas (explicitly by using ``revert`` or
+     requires more than the allotted amount of gas (explicitly by using ``require``,
+     ``assert``, ``revert``, ``throw`` or
      because the operation is just too expensive) - it "runs out of gas" (OOG).
      If you use ``transfer`` or ``send`` with a return value check, this might provide a
      means for the recipient to block progress in the sending contract. Again, the best practice here is to use

docs/solidity-by-example.rst

@@ -94,7 +94,7 @@ of votes.
             // called incorrectly. But watch out, this
             // will currently also consume all provided gas
             // (this is planned to change in the future).
-            require(msg.sender == chairperson || !voters[voter].voted);
+            require((msg.sender == chairperson) && !voters[voter].voted);
             voters[voter].weight = 1;
         }
 
@@ -268,11 +268,11 @@ activate themselves.
 
             // Revert the call if the bidding
             // period is over.
-            require(now < auctionStart + biddingTime);
+            require(now <= auctionStart + biddingTime);
 
             // If the bid is not higher, send the
             // money back.
-            require(msg.value <= highestBid);
+            require(msg.value > highestBid);
             
             if (highestBidder != 0) {
                 // Sending back the money by simply using
@@ -322,7 +322,7 @@ activate themselves.
             // external contracts.
 
             // 1. Conditions
-            require(now >= auctionStart + biddingTime); // auction did not yet end
+            require(now >= (auctionStart + biddingTime)); // auction did not yet end
             require(!ended); // this function has already been called
 
             // 2. Effects
@@ -446,11 +446,9 @@ high or low invalid bids.
             onlyBefore(revealEnd)
         {
             uint length = bids[msg.sender].length;
-            require(
-                _values.length == length &&
-                _fake.length == length &&
-                _secret.length == length
-            );
+            require(_values.length == length);
+            require(_fake.length == length);
+            require(_secret.length == length);
 
             uint refund;
             for (uint i = 0; i < length; i++) {
@@ -609,8 +607,10 @@ Safe Remote Purchase
             // otherwise, the contracts called using `send` below
             // can call in again here.
             state = State.Inactive;
-            // This actually allows both the buyer and the seller to
+
+            // NOTE: This actually allows both the buyer and the seller to
             // block the refund - the withdraw pattern should be used.
+
             buyer.transfer(value);
             seller.transfer(this.balance));
         }