File 0491-Mention-action-handling-details-in-user-s-guide.patch of Package erlang

From 22db0a0d909692f3995760d9eaf1def1aaff14a5 Mon Sep 17 00:00:00 2001
From: Raimo Niskanen <raimo@erlang.org>
Date: Thu, 1 Aug 2019 08:57:18 +0200
Subject: [PATCH 2/2] Mention action handling details in user's guide

---
 system/doc/design_principles/statem.xml | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/system/doc/design_principles/statem.xml b/system/doc/design_principles/statem.xml
index 23e9054547..81a0c617f1 100644
--- a/system/doc/design_principles/statem.xml
+++ b/system/doc/design_principles/statem.xml
@@ -624,6 +624,18 @@ State(S) x Event(E) -> Actions(A), State(S')</pre>
       and set a time-out to use absolute instead of relative time
       (using the <c>Opts</c> field).
     </p>
+    <p>
+      Among these <em>transition actions</em> only to reply to a caller
+      is an immediate action.  The others are collected and handled
+      later during the <em>state transition</em>.
+      <seealso marker="#Inserted Events">Inserted Events</seealso>
+      are stored and inserted all together,
+      and the rest set transition options
+      where the last of a specific type override the previous.
+      See the description of a <em>state transition</em>
+      in the <c>gen_statem(3)</c> manual page for type
+      <seealso marker="stdlib:gen_statem#type-transition_option"><c>transition_option()</c></seealso>.
+    </p>
   </section>
 
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