File 3963-Fix-types-for-getbyname-2-3.patch of Package erlang

From 9edbf8a5ab74fb7e7b6e433e8827c02469281aad Mon Sep 17 00:00:00 2001
From: Raimo Niskanen <raimo@erlang.org>
Date: Mon, 21 Mar 2022 15:21:51 +0100
Subject: [PATCH 3/5] Fix types for getbyname/2,3

---
 lib/kernel/doc/src/inet_res.xml | 22 ++++++++++++++++++----
 lib/kernel/src/inet_res.erl     | 16 +++++++++++++---
 2 files changed, 31 insertions(+), 7 deletions(-)

diff --git a/lib/kernel/doc/src/inet_res.xml b/lib/kernel/doc/src/inet_res.xml
index 0d654bbc0e..9f2304a630 100644
--- a/lib/kernel/doc/src/inet_res.xml
+++ b/lib/kernel/doc/src/inet_res.xml
@@ -195,6 +195,9 @@ inet_dns:record_type(_) -> undefined.</pre>
           in the UTF-8 coding standard.</p>
       </desc>
     </datatype>
+    <datatype>
+      <name name="hostent"/>
+    </datatype>
   </datatypes>
 
   <funcs>
@@ -204,9 +207,20 @@ inet_dns:record_type(_) -> undefined.</pre>
       <fsummary>Resolve a DNS record of the specified type for the specified
       host.</fsummary>
       <desc>
-        <p>Resolves a DNS record of the specified type for the specified host,
-          of class <c>in</c>. Returns, on success, a <c>hostent()</c> record
-          with <c>dns_data()</c> elements in the address list field.</p>
+        <p>Resolves a DNS record of the specified <c><anno>Type</anno></c>
+          for the specified host, of class <c>in</c>.
+          Returns, on success, when resolving a
+          <c><anno>Type</anno>&nbsp;=&nbsp;a|aaaa</c> DNS record,
+          a <c>#hostent{}</c> record with
+          <c>#hostent.h_addrtype&nbsp;=&nbsp;inet|inet6</c>,
+          respectively; see
+          <seetype marker="inet#hostent"><c>inet:hostent()</c></seetype>.</p>
+        <p>When resolving other
+          <c><anno>Type</anno>&nbsp;=&nbsp;rr_type()</c>:s
+          also returns a <c>#hostent{}</c> record but with
+          <c>#hostent.h_addrtype&nbsp;=&nbsp;</c><seetype marker="#rr_type"><c>rr_type()</c></seetype>, and
+          <c>#hostent.h_addr_list&nbsp;=&nbsp;</c>[<seetype marker="#dns_data"><c>dns_data()</c></seetype>]; see
+          <seetype marker="#hostent"><c>hostent()</c></seetype>.</p>
         <p>This function uses resolver option <c>search</c> that
           is a list of domain names. If the name to resolve contains
           no dots, it is prepended to each domain name in the
diff --git a/lib/kernel/src/inet_res.erl b/lib/kernel/src/inet_res.erl
index 4e71944492..b0d5b6dc7b 100644
--- a/lib/kernel/src/inet_res.erl
+++ b/lib/kernel/src/inet_res.erl
@@ -453,10 +453,20 @@ gethostbyname_tm(_Name, _Family, _Timer) ->
 %% Caches the answer.
 %% --------------------------------------------------------------------------
 
+%% Duplicate of inet.hrl: #hostent{}, but with DNS RR types in h_addrtype
+%% and dns_data() in h_addr_list.
+-type hostent() ::
+        {'hostent',
+         H_name      :: inet:hostname(),
+         H_aliases   :: [inet:hostname()],
+         H_addrtype  :: rr_type(),
+         H_length    :: non_neg_integer(),
+         H_addr_list :: [dns_data()]}.
+
 -spec getbyname(Name, Type) -> {ok, Hostent} | {error, Reason} when
       Name :: dns_name(),
       Type :: rr_type(),
-      Hostent :: inet:hostent(),
+      Hostent :: inet:hostent() | hostent(),
       Reason :: inet:posix() | res_error().
 
 getbyname(Name, Type) -> 
@@ -466,7 +476,7 @@ getbyname(Name, Type) ->
       Name :: dns_name(),
       Type :: rr_type(),
       Timeout :: timeout(),
-      Hostent :: inet:hostent(),
+      Hostent :: inet:hostent() | hostent(),
       Reason :: inet:posix() | res_error().
 
 getbyname(Name, Type, Timeout) ->
-- 
2.34.1