From b89e433f4f48f5be8d35d7a7eaf45d5ac45169fd Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Mon, 13 Jul 2020 19:03:05 +0200
Subject: add more detail to coin state machine

---
 doc/system/taler/coin.dot   |   4 +++-
 doc/system/taler/coin.pdf   | Bin 17066 -> 17151 bytes
 doc/system/taler/design.tex |   7 ++++---
 3 files changed, 7 insertions(+), 4 deletions(-)

(limited to 'doc')

diff --git a/doc/system/taler/coin.dot b/doc/system/taler/coin.dot
index ab1f8139f..3112a1b65 100644
--- a/doc/system/taler/coin.dot
+++ b/doc/system/taler/coin.dot
@@ -6,7 +6,8 @@ digraph Coin {
   partial [color=blue, label="dirty coin", shape="box"];
   revoked [color=blue, label="revoked coin", shape="box"];
   zombie [color=blue, label="zombie coin", shape="box"];
-  spent [color=blue, label="spent coin", shape="doublecircle"];
+  spent [color=blue, label="spent coin", shape="box"];
+  wired [color=blue, label="wired coin", shape="doublecircle"];
   expired [color=blue, label="expired coin", shape="doublecircle"];
 
   subgraph {
@@ -36,6 +37,7 @@ digraph Coin {
   melt->spent;
   spent->refund;
   refund->partial;
+  spent->wired [style=dotted];
   partial->expired [style=dotted];
   partial->melt;
   partial->deposit [color=red];
diff --git a/doc/system/taler/coin.pdf b/doc/system/taler/coin.pdf
index a5590b75e..dcd47292e 100644
Binary files a/doc/system/taler/coin.pdf and b/doc/system/taler/coin.pdf differ
diff --git a/doc/system/taler/design.tex b/doc/system/taler/design.tex
index d78acac19..535dc51ac 100644
--- a/doc/system/taler/design.tex
+++ b/doc/system/taler/design.tex
@@ -727,8 +727,9 @@ the {\em withdraw} protocol or the refresh protocol. The most common scenario
 is that the {\em fresh coin} is {\em deposited}. This payment creates a
 deposit (see Figure~\ref{fig:deposit:states}) and either a {\em dirty coin}
 (if the payment was for a fraction of the coin's value) or a {\em spent coin}.
-A spent coin can be {\em refunded} by the merchant (until the deposit is due),
-creating a {\em dirty coin}.
+A spent coin can be {\em refunded} by the merchant, creating a {\em dirty
+  coin}. Once the exchange has aggregated a coin and wired the amount to the
+merchant, a coin can no longer be refunded.
 
 A {\em fresh coin} may also be subject to key {\em revocation}, at which point
 the wallet ends up with a {\em revoked coin}.  At this point, the wallet can
@@ -754,7 +755,7 @@ when the committment made for the {\em refresh session} is checked during the
 
 \begin{figure}
   \begin{center}
-    \includegraphics[scale=0.75]{taler/coin.pdf}
+    \includegraphics[scale=0.65]{taler/coin.pdf}
   \end{center}
   \caption{State machine of a coin.}
   \label{fig:coin:states}
-- 
cgit v1.2.3