Mono injects two tab characters (i.e. \t\t) in front of any text displayed
in multiline text boxes that are embedded as content in an <asp:TableCell>
within an <asp:TableRow> of an <asp:Table>.
Two additional tab characters are injected at every single postback.
This happens with the Mono Framework 2.10.8.
It can be observed with web applications rendered with xsp4 as well as with mod-mono-server4.
- /Library/Frameworks/Mono.framework/Versions/2.10.8/bin/mono
- /Library/Frameworks/Mono.framework/Versions/2.10.8/lib/mono/4.0/xsp4.exe
- /Library/Frameworks/Mono.framework/Versions/2.10.8/lib/mono/4.0/mod-mono-server4.exe
- Mac OS/X Version 10.7.2
$ mono --version
Mono JIT compiler version 2.10.8 (tarball Mon Dec 19 17:43:18 EST 2011)
Copyright (C) 2002-2011 Novell, Inc, Xamarin, Inc and Contributors. www.mono-project.com
TLS: normal
SIGSEGV: normal
Notification: kqueue
Architecture: x86
Disabled: none
Misc: debugger softdebug
LLVM: yes(2.9svn-mono)
GC: Included Boehm (with typed GC)
$ xsp4 --version
xsp4.exe 2.10.2.0
Copyright (C) 2002-2011 Novell, Inc.
Minimalistic web server for testing System.Web
$ mod-mono-server4 --version
mod-mono-server4.exe 2.10.2.0
(c) (c) 2002-2011 Novell, Inc.
Mod_mono backend for XSP
WeirdTabs is a minimalistic application designed to clearly demonstrate the problem.
The application only has one single page, the Default.aspx page. It
only has three controls:
- Multiline
<asp:TextBox>with hardcoded initial textFree - Multiline
<asp:TextBox>with hardcoded initial textEmbedded. This box is nested within an<asp:TableCell>. - Button to trigger a postback
<%@ Page Language="C#" Inherits="WeirdTabs.Default" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html>
<head runat="server">
<title>WeirdTabs</title>
</head>
<body>
<form id="form1" runat="server">
<asp:TextBox runat="server" Width="200px" Rows="5" TextMode="MultiLine">Free</asp:TextBox>
<asp:Table runat="server">
<asp:TableRow>
<asp:TableCell>
<asp:TextBox runat="server" Width="200px" Rows="5" TextMode="MultiLine">Embedded</asp:TextBox>
</asp:TableCell>
</asp:TableRow>
</asp:Table>
<asp:Button runat="server" Text="refresh"></asp:Button>
</form>
</body>
</html>
using System.Web.UI;
namespace WeirdTabs
{
public partial class Default : Page
{
}
}
This application should display two multiline text areas with text content sitting right at column 0 and row 0.
The first box should have Free as text, the second box should show
Embedded.
Whenever the refresh button is clicked, this page should be rerendered
without causing any change to the content of the text boxes.
The first box displays Free as it is supposed to.
The second box displays
\t\tEmbedded
thus displaying two injected tabs in front of the text.
Note that the \t escape sequence shown in this text represents one
single tab character with hex value x09.
At every single postback, two more tabs are injected, as in
\t\t\t\tEmbedded
\t\t\t\t\t\tEmbedded
\t\t\t\t\t\t\t\tEmbedded, etc.
This test application behaves as expected when running on an IIS server.
This erroneous behaviour occurs with any multiline <asp:TextBox> that is
content of an <asp:TableCell> in an <asp:TableRow> of an <asp:Table>.
-
The error does not occur with non-multiline text nor with non-embedded text boxes.
-
The content of the
WeirdTabsboxes is hard coded to keep it simple. The error occurs regardless of the source of the text box content.