Tweak map-valued decode

Use the same [MsgName | Avps] representation as for the list decode, but
with Avps a map instead of a AVP name/values list. As a result, don't
set the message/AVP name on an additional key in the map, which felt a
bit odd. Messages are [MsgName :: atom() | map()], Grouped AVPs are just
map().

Fix at least one problem in the traffic suite along the way: with
decode_format false, the own decode in to_map/2 didn't know whether or
not to decode strings, resulting on some failures.

2 files changed, 13 insertions, 7 deletions

diff --git a/lib/diameter/doc/src/diameter.xml b/lib/diameter/doc/src/diameter.xml
index a7f001e096..43cb3a538c 100644
--- a/lib/diameter/doc/src/diameter.xml
+++ b/lib/diameter/doc/src/diameter.xml
@@ -539,7 +539,7 @@ that matches no peer.</p>
 <p>
 The <c>host</c> and <c>realm</c> filters cause the Destination-Host
 and Destination-Realm AVPs to be extracted from the
-outgoing request, assuming it to be a record-, list- or map-valued
+outgoing request, assuming it to be a record- or list-valued
 <c>&codec_message;</c>, and assuming at most one of each AVP.
 If this is not the case then the <c>{host|realm, &dict_DiameterIdentity;}</c>
 filters must be used to achieve the desired result.
@@ -802,10 +802,16 @@ be matched by corresponding &capability; configuration, of
 <c>{decode_format, record | list | map | false}</c></tag>
 <item>
 <p>
-The type of decoded messages and grouped AVPs in the <c>msg</c> field
+The format of decoded messages and grouped AVPs in the <c>msg</c> field
 of diameter_packet records and <c>value</c> field of diameter_avp
 records respectively.
-If <c>false</c> then the fields are set this value.
+If <c>record</c> then a record whose definition is generated from the
+dictionary file in question.
+If <c>list</c> or <c>map</c> then a <c>[Name | Avps]</c> pair where
+<c>Avps</c> is either a list of AVP name/values pairs or a map keyed on
+AVP names respectively.
+If <c>false</c> then the representation is omitted and <c>msg</c> and
+<c>value</c> fields are set to <c>false</c>.
 See also &codec_message;.</p>
 
 <p>
diff --git a/lib/diameter/doc/src/diameter_codec.xml b/lib/diameter/doc/src/diameter_codec.xml
index 4df8e788b7..0846334d23 100644
--- a/lib/diameter/doc/src/diameter_codec.xml
+++ b/lib/diameter/doc/src/diameter_codec.xml
@@ -230,7 +230,8 @@ header.</p>
 </item>
 
 <tag>
-<marker id="message"/><c>message() = record() | list() | map()</c></tag>
+<marker id="message"/><c>message() = record()
+                                   | maybe_improper_list()</c></tag>
 <item>
 <p>
 The representation of a Diameter message as passed to
@@ -240,9 +241,8 @@ a message as defined in a dictionary file is encoded as a record with
 one field for each component AVP.
 Equivalently, a message can also be encoded as a list whose head is
 the atom-valued message name (as specified in the relevant dictionary
-file) and whose tail is a list of <c>{AvpName, AvpValues}</c> pairs,
-or as a map with values keyed on AVP names and the message name in key
-<c>:name</c>.
+file) and whose tail is either a list of AVP name/values
+pairs or a map with values keyed on AVP names.
 The format at decode is determined by &mod_service_opt;
 <c>decode_format</c>.
 Any of the formats is accepted at encode.</p>