refactor: revert most of what I did for #2424

This changes the meaning of an empty database setting for a PostgreSQL session:
- old: empty meant "postgres", and "!" meant empty
- new: empty means empty now

Refs #2424 and #2442

Author: ansgarbecker

source/connections.pas

@@ -1309,34 +1309,21 @@ procedure Tconnform.editDatabasesRightButtonClick(Sender: TObject);
     // Try to connect and lookup database names
     Params := CurrentParams;
     Connection := Params.CreateConnection(Self);
-    Connection.Parameters.AllDatabasesStr := TPgConnection.DBNAME_EMPTY;
+    Connection.Parameters.AllDatabasesStr := '';
     Connection.LogPrefix := SelectedSessionPath;
     Connection.OnLog := Mainform.LogSQL;
     FPopupDatabases := TPopupMenu.Create(Self);
     //FPopupDatabases.AutoHotkeys := maManual;
     Screen.Cursor := crHourglass;
     try
       Connection.Active := True;
-      if Params.IsAnyPostgreSQL then begin
-        Databases := Connection.GetCol('SELECT datname FROM pg_database WHERE datistemplate=FALSE');
-        Item := TMenuItem.Create(FPopupDatabases);
-        Item.Caption := TPgConnection.DBNAME_EMPTY + ' (' + _('No database') + ')';
-        Item.Tag := TPgConnection.DBTAG_EMPTY;
-        Item.OnClick := MenuDatabasesClick;
-        Item.AutoCheck := True;
-        Item.RadioItem := True;
-        FPopupDatabases.Items.Add(Item);
-      end
-      else begin
+      if Params.NetTypeGroup = ngPgSQL then
+        Databases := Connection.GetCol('SELECT datname FROM pg_database WHERE datistemplate=FALSE')
+      else
         Databases := Connection.AllDatabases;
-      end;
       for DB in Databases do begin
         Item := TMenuItem.Create(FPopupDatabases);
         Item.Caption := DB;
-        if Params.IsAnyPostgreSQL and (DB = TPgConnection.DBNAME_DEFAULT) then begin
-          Item.Caption := Item.Caption + ' (' + _('Default') + ')';
-          Item.Tag := TPgConnection.DBTAG_DEFAULT;
-        end;
         Item.OnClick := MenuDatabasesClick;
         Item.AutoCheck := True;
         Item.RadioItem := Params.IsAnyPostgreSQL;
@@ -1352,14 +1339,7 @@ procedure Tconnform.editDatabasesRightButtonClick(Sender: TObject);
   // Check/uncheck items, based on semicolon list
   Databases := Explode(';', editDatabases.Text);
   for Item in FPopupDatabases.Items do begin
-    case Item.Tag of
-      TPgConnection.DBTAG_EMPTY:
-        Item.Checked := Databases.Contains(TPgConnection.DBNAME_EMPTY);
-      TPgConnection.DBTAG_DEFAULT:
-        Item.Checked := Databases.Contains(TPgConnection.DBNAME_DEFAULT) or Databases.IsEmpty;
-      else
-        Item.Checked := Databases.IndexOf(Item.Caption) > -1;
-    end;
+    Item.Checked := Databases.IndexOf(Item.Caption) > -1;
   end;
   Databases.Free;
 
@@ -1376,12 +1356,8 @@ procedure Tconnform.MenuDatabasesClick(Sender: TObject);
 begin
   Databases := TStringList.Create;
   for Item in FPopupDatabases.Items do begin
-    if Item.Checked then begin
-      if Item.Tag in [TPgConnection.DBTAG_EMPTY, TPgConnection.DBTAG_DEFAULT] then // Remove hint
-        Databases.Add(ReplaceRegExpr('\s\(.+$', Item.Caption, ''))
-      else
-        Databases.Add(Item.Caption);
-    end;
+    if Item.Checked then
+      Databases.Add(Item.Caption);
   end;
   SelStart := editDatabases.SelStart;
   editDatabases.Text := Implode(';', Databases);

source/dbconnection.pas

@@ -702,11 +702,6 @@   TSqlSrvConnection = class(TDBConnection)
   TPGRawResults = Array of PPGresult;
   TPQerrorfields = (PG_DIAG_SEVERITY, PG_DIAG_SQLSTATE, PG_DIAG_MESSAGE_PRIMARY, PG_DIAG_MESSAGE_DETAIL, PG_DIAG_MESSAGE_HINT, PG_DIAG_STATEMENT_POSITION, PG_DIAG_INTERNAL_POSITION, PG_DIAG_INTERNAL_QUERY, PG_DIAG_CONTEXT, PG_DIAG_SOURCE_FILE, PG_DIAG_SOURCE_LINE, PG_DIAG_SOURCE_FUNCTION);
   TPgConnection = class(TDBConnection)
-    const
-      DBNAME_DEFAULT = 'postgres';
-      DBNAME_EMPTY = '!';
-      DBTAG_EMPTY = 1;
-      DBTAG_DEFAULT = 2;
     private
       FHandle: PPGconn;
       FLib: TPostgreSQLLib;
@@ -2734,18 +2729,13 @@ procedure TSqlSrvConnection.SetActive(Value: Boolean);
 
 procedure TPgConnection.SetActive(Value: Boolean);
 var
-  dbname, ConnectionString, OptionValue, Error: String;
+  ConnectionString, OptionValue, Error: String;
   ConnectOptions: TStringList;
   FinalHost, ErrorHint: String;
   FinalPort, i: Integer;
 begin
   if Value then begin
     DoBeforeConnect;
-    // Simon Riggs:
-    // "You should connect as "postgres" database by default, with an option to change. Don't use template1"
-    dbname := FParameters.AllDatabasesStr;
-    if dbname = '' then
-      dbname := DBNAME_DEFAULT;
 
     // Prepare special stuff for SSH tunnel
     FinalHost := FParameters.Hostname;
@@ -2763,8 +2753,8 @@ procedure TPgConnection.SetActive(Value: Boolean);
       .AddPair('password', FParameters.Password)
       .AddPair('application_name', APPNAME)
       .AddPair('sslmode', 'disable');
-    if dbname <> DBNAME_EMPTY then
-      ConnectOptions.AddPair('dbname', dbname);
+    if not FParameters.AllDatabasesStr.IsEmpty then
+      ConnectOptions.AddPair('dbname', FParameters.AllDatabasesStr);
     if FParameters.WantSSL then begin
       // Be aware .AddPair would add duplicates
       case FParameters.SSLVerification of