Missing fields in a data-form response are now interpreted as an empty value

7 files changed, 49 insertions, 11 deletions

diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index 4966a3c..f24faf4 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -19,6 +19,9 @@ Version 8.0
 - A Nick field has been added in the IRC server configuration form, to let
   the user force a nickname whenever a channel on the server is joined.
 - Multiple admins can now be listed in the admin field, separated with a colon.
+- Missing fields in a data-form response are now properly interpreted as
+  an empty value, and not the default value. Gajim users were not able to
+  empty a field of type text-multi because of this issue.
 
 Version 7.3
 ===========
diff --git a/src/database/column.hpp b/src/database/column.hpp
index 50c9c14..837aa3f 100644
--- a/src/database/column.hpp
+++ b/src/database/column.hpp
@@ -9,18 +9,30 @@ struct Column
         value{default_value} {}
     Column():
         value{} {}
+    void clear()
+    {
+      this->value = {};
+    }
     using real_type = T;
     T value{};
 };
 
+template <typename T>
+struct UnclearableColumn: public Column<T>
+{
+    using Column<T>::Column;
+    void clear()
+    { }
+};
+
 struct ForeignKey: Column<std::size_t> {
     static constexpr auto name = "fk_";
 };
 
-struct Id: Column<std::size_t> {
+struct Id: UnclearableColumn<std::size_t> {
     static constexpr std::size_t unset_value = static_cast<std::size_t>(-1);
     static constexpr auto name = "id_";
     static constexpr auto options = "PRIMARY KEY";
 
-    Id(): Column<std::size_t>(unset_value) {}
+    Id(): UnclearableColumn<std::size_t>(unset_value) {}
 };
diff --git a/src/database/database.hpp b/src/database/database.hpp
index d986ecc..30ffcb4 100644
--- a/src/database/database.hpp
+++ b/src/database/database.hpp
@@ -27,15 +27,15 @@ class Database
 
   struct Uuid: Column<std::string> { static constexpr auto name = "uuid_"; };
 
-  struct Owner: Column<std::string> { static constexpr auto name = "owner_"; };
+  struct Owner: UnclearableColumn<std::string> { static constexpr auto name = "owner_"; };
 
-  struct IrcChanName: Column<std::string> { static constexpr auto name = "ircchanname_"; };
+  struct IrcChanName: UnclearableColumn<std::string> { static constexpr auto name = "ircchanname_"; };
 
-  struct Channel: Column<std::string> { static constexpr auto name = "channel_"; };
+  struct Channel: UnclearableColumn<std::string> { static constexpr auto name = "channel_"; };
 
-  struct IrcServerName: Column<std::string> { static constexpr auto name = "ircservername_"; };
+  struct IrcServerName: UnclearableColumn<std::string> { static constexpr auto name = "ircservername_"; };
 
-  struct Server: Column<std::string> { static constexpr auto name = "server_"; };
+  struct Server: UnclearableColumn<std::string> { static constexpr auto name = "server_"; };
 
   struct Date: Column<time_point::rep> { static constexpr auto name = "date_"; };
 
diff --git a/src/database/row.hpp b/src/database/row.hpp
index 27caf43..1253f93 100644
--- a/src/database/row.hpp
+++ b/src/database/row.hpp
@@ -1,7 +1,5 @@
 #pragma once
 
-#include <utils/is_one_of.hpp>
-
 #include <type_traits>
 
 template <typename... T>
@@ -25,7 +23,24 @@ struct Row
     return col.value;
   }
 
-public:
+  void clear()
+  {
+    this->clear_col<0>();
+  }
+
   std::tuple<T...> columns;
   std::string table_name;
+
+private:
+  template <std::size_t N>
+  typename std::enable_if<N < sizeof...(T), void>::type
+  clear_col()
+  {
+    std::get<N>(this->columns).clear();
+    this->clear_col<N+1>();
+  }
+  template <std::size_t N>
+  typename std::enable_if<N == sizeof...(T), void>::type
+  clear_col()
+  { }
 };
diff --git a/src/xmpp/biboumi_adhoc_commands.cpp b/src/xmpp/biboumi_adhoc_commands.cpp
index 53806d6..b62dcfc 100644
--- a/src/xmpp/biboumi_adhoc_commands.cpp
+++ b/src/xmpp/biboumi_adhoc_commands.cpp
@@ -177,6 +177,7 @@ void ConfigureGlobalStep2(XmppComponent& xmpp_component, AdhocSession& session,
     {
       const Jid owner(session.get_owner_jid());
       auto options = Database::get_global_options(owner.bare());
+      options.clear();
       for (const XmlNode* field: x->get_children("field", "jabber:x:data"))
         {
           const XmlNode* value = field->get_child("value", "jabber:x:data");
@@ -400,7 +401,8 @@ void ConfigureIrcServerStep2(XmppComponent&, AdhocSession& session, XmlNode& com
         server_domain = target.local;
       auto options = Database::get_irc_server_options(owner.local + "@" + owner.domain,
                                                       server_domain);
-      auto commands = Database::get_after_connection_commands(options);
+      options.clear();
+      Database::AfterConnectionCommands commands{};
 
       for (const XmlNode* field: x->get_children("field", "jabber:x:data"))
         {
@@ -608,6 +610,7 @@ bool handle_irc_channel_configuration_form(XmppComponent& xmpp_component, const
           const Iid iid(target.local, {});
           auto options = Database::get_irc_channel_options(requester.bare(),
                                                            iid.get_server(), iid.get_local());
+          options.clear();
           for (const XmlNode *field: x->get_children("field", "jabber:x:data"))
             {
               const XmlNode *value = field->get_child("value", "jabber:x:data");
diff --git a/tests/database.cpp b/tests/database.cpp
index 15c117b..070a460 100644
--- a/tests/database.cpp
+++ b/tests/database.cpp
@@ -64,6 +64,10 @@ TEST_CASE("Database")
       CHECK(o.col<Database::EncodingIn>() == "ISO-8859-1");
       CHECK(o.col<Database::RecordHistoryOptional>().is_set == true);
       CHECK(o.col<Database::RecordHistoryOptional>().value == false);
+
+      o.clear();
+      CHECK(o.col<Database::EncodingIn>() == "");
+      CHECK(o.col<Database::Owner>() == "zouzou@example.com");
     }
 
   SECTION("Channel options with server default")
diff --git a/tests/end_to_end/__main__.py b/tests/end_to_end/__main__.py
index 82321eb..2f6fc28 100644
--- a/tests/end_to_end/__main__.py
+++ b/tests/end_to_end/__main__.py
@@ -2885,6 +2885,7 @@ if __name__ == '__main__':
                      partial(expect_stanza, ("/iq[@type='result']/commands:command[@node='configure'][@sessionid][@status='executing']",
                                              "/iq/commands:command/dataform:x[@type='form']/dataform:title[text()='Configure the IRC server irc.localhost']",
                                              "/iq/commands:command/dataform:x[@type='form']/dataform:instructions[text()='Edit the form, to configure the settings of the IRC server irc.localhost']",
+                                             "!/iq/commands:command/dataform:x/dataform:field[@var='tls_ports']/dataform:value",
                                              "!/iq/commands:command/dataform:x[@type='form']/dataform:field[@var='pass']/dataform:value",
                                              "!/iq/commands:command/dataform:x[@type='form']/dataform:field[@var='after_connect_commands']/dataform:value",
                                              "!/iq/commands:command/dataform:x[@type='form']/dataform:field[@var='username']/dataform:value",