1248238 - Useless second message "Do you really want to leave" from particular web page edit

Status: NEW

(SeaMonkey :: General, defect)

Description

[Rainer Bielefeld]

Steps how to reproduce with unofficial (from <http://seamonkey.callek.net/contrib/>)  en-US SeaMonkey 2.44a1  Mozilla/5.0 (Windows NT 6.1; x64; rv:47.0)  Gecko/20100101 Firefox/47.0 Build 20160208090255  (Default Classic Theme)  on German WIN7 64bit:

1. Open a Wordpress page for editing (you will need permissions)
2. Add a blank somewhere
3. Click "Close-Tab-X" to close the tab
   » As expected Message appears: Are You sure? This page is asking you 
     to confirm that you want to leave - data you have entered may not
     be saved.
4. [Leave]
   » TAB will be closed as expected
   Bug: unexpectedly the message from step 3 appears a second time, and 
        option [Stay on page] is useless, page has already been left.

The useless second message does not appear on all edit pages. Works fine:
11. 1. Open a Wiki page for editing (you will need permissions) like
    <https://wiki.mozilla.org/index.php?title=SeaMonkey/StatusMeetings/2016-02-02&action=edit>
12. Add a blank somewhere
13. Click "Close-Tab-X" to close the tab
    » As expected Message appears: Are You sure? This page is asking you 
      to confirm that you want to leave - data you have entered may not
      be saved.
14. [Leave]
    » TAB will be closed as expected, no clone of message from 13 appears
 
Additional information
a) Wordpress also might be involved, but the second useless message 
   does not appear when I do steps 1 and following with 
   FF 47.0a1 (2016-02-12)
b) Seems unrelated to add-ons, bug also reproducible in safe mode without
   add-ons active
c) seems not related to User Profile, bug also reproducible with a 
   completely new User Profile
d) Not related to Theme, also reproducible with “Modern” Theme

Comment 1

[Rainer Bielefeld]

e) For example reproducible with SM project blog

Comment 2

[Rainer Bielefeld]

f) the effect also is reproducible with Attachment 803605 [details] for c,
   but I am not sure whether this one has the same roots: 
   21. open attachment from Attachment 803605 [details] Details for Bug 915597
   22. Click empty place holder at top left end or page contents
   23. Click Tab-Close-x
   » same as in step 3 and following

Comment 3

[Rainer Bielefeld]

Please ignore comment 2, wrong attachment!

f) the effect also is reproducible with Attachment 8553891 [details] for Bug 1125285
   but I am not sure whether this one has the same roots: 
   21. open attachment from Bug 1125285 with 'rightclick / new TAB' → 
       change to new TAB if necessary
   22. Click empty place holder at top left end of page contents
   23. Click Tab-Close-x
   » same as in step 3 and following

Comment 4

[Rainer Bielefeld]

f): I doubt that that this one is a DUP of Bug 1125285
    This one already is reproducible with SM 2.16 
    Attachment 8553891 [details] for Bug 1125285 shows a very different behavior with 2.19:
    Click on white placeholder (button) will bring up the "are your sure" message.

Comment 5

[Rainer Bielefeld]

g) REPRODUCIBLE with  English SeaMonkey 2.43a1  (X11; Linux x86_64; rv:46.0) 
   Gecko/20100101 Firefox/46.0 Build 20160109003001  (Default Theme) 
   on VirtualBox Ubuntu 14.04 LTS

Comment 6

[Rainer Bielefeld]

h) Already REPRODUCIBLE with  DE  SeaMonkey 2.0  (Windows NT 6.1; WOW64;
   rv:1.9.1.4)  Gecko/20091017  Build 20091017081335  (Classic Theme) 
   on German WIN7 64bit
i) Not a problem with IE11

Comment 8

[Rainer Bielefeld]

New due to comment 7