156845 - Javascript code does not submit correct button that was clicked

Status: RESOLVED INVALID

(Core :: DOM: Core & HTML, defect)

Description

[Adam Bodnar]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 Galeon/1.2.5 (X11; Linux i686; U;) Gecko/0
BuildID:    20020630

There are 3 submit buttons, all named the same, but with different values. Add,
Edit, and Delete. When the Delete button is clicked it invokes a OnClick that
calls javascript function to return a value. The javascript function sets a
variable to a true or false value the window.confirm returns. Then an if
statement to see if the user clicked Yes. If so, a document.formname.submit() is
issued. In Mozilla, the form is just submitted, but the Delete button's value
isn't sent along. In other browsers, the value of the Delete button is sent.

Reproducible: Always
Steps to Reproduce:
See Additional Information for code to reproduce.

If the code doesn't display correct, contact me and I will setup a link that
displays this problem.

<script>
function validate_delete() {
 var confdelete = window.confirm('Are you sure you want to delete this user?')
 if (confdelete == true) {
  document.users.submit()
 } else {
  return false
 }
}
</script>

<form name=users method=POST>
<input type=submit name=action value=Add>
<input type=submit name=action value=Edit>
<input type=submit name=action value=Delete onClick="return validate_delete()">

Comment 1

[Alfonso Martinez]

it seems very wrong to put several buttons with the same name.

Comment 2

[Phil Schwartau]

Browser, not engine ---> DOM Level 0

Confirming report using Mozilla trunk binary 20020701xx on WinNT.
Note: I can see the bug even if I delete the two other buttons:

<script>
function validate_delete()
{
  var confdelete = window.confirm('Are you sure you want to delete this user?')
  if (confdelete == true)
  {
    document.users.submit();
    return true;
  }
  else
  {
    return false;
  }
}
</script>

<form name=users method=submit>
<input type=submit name=action value=Delete onClick="return validate_delete()">
</form>


I will attach this below. Note I changed the |method| attribute
from "post" to "submit", so that we can see the query items appear
in the URL bar once the submit button is hit -

Comment 3

[Phil Schwartau]

Attachment: HTML testcase

Comment 4

[Phil Schwartau]

Comment on attachment 91014 [details]
HTML testcase

Oops! Have to obsolete the attachment; the Bugzilla server doesn't like us to
submit to it!

Comment 5

[Phil Schwartau]

Just save the source in Comment #2 locally and click the Delete button.
Note I have changed the form method to "submit" instead of "post".

I have also added a |return true;| to the positive branch of the 
validate_delete() function -

Here's what I get. My URL on load is 
        file:///C|/WINNT/Profiles/pschwartau/Desktop/156845.html

After clicking the Delete button (and confirming "OK"), I have:

NN4.7   file:///C|/WINNT/Profiles/pschwartau/Desktop/156845.html?action=Delete
Mozilla file:///C:/WINNT/Profiles/pschwartau/Desktop/156845.html?  
IE6     file:///C:/WINNT/Profiles/pschwartau/Desktop/156845.html?action=Delete


So in Mozilla, the value of the <input> is not being sent -

Comment 6

[Boris Zbarsky [:bzbarsky]]

What is happening here is that the case when you call document.users.submit()
does not return false, so the <input type="submit"> also submits.  You get two
submissions -- one from the submit() call, one from the <input>.

In Mozilla, we do not allow multiple submits from the same form at the same time
(since that can lead to bad double-submit problems on the server side; in your
case you would get two deletions if your server-side code did not check the
value of the button used to submit (eg if there was only one submission
button)).  So the first submit (from calling submit()) happens, and that does
not know what button to send.  The second submit (from the <input type="submit">
does not happen).

It looks like your code should just return "true" in the "confdelete == true"
case and let the <input type="submit"> handle the submission...  

Comment 7

[John Keiser (jkeiser)]

Yep, change to "return true."  INVALID. 
http://mozilla.freezope.org/docnotes/FormBugsFAQ#submit_name_value