794089 - Delete key changes formatting in prior text instead of removing line break after

Status: NEW

(MailNews Core :: Composition, defect)

Description

[WBT]

Attachment: Word 2010 doc with source material to copy in to Compose window

Edit the attached message as new, to begin.  Place your cursor on one of the blank lines in there. Copy the content of the Word doc that's also part of this bug report and paste it in.  Then press delete and see what happens.   What I see is that the titles pasted in become black and bold with a sans serif font (instead of blue italic with a serif font, Word 2010's default heading 4 style), and all the comments become formatted like the body text above and below.  If you pressed backspace, you may also observe the appearance of formatting information as in Bug 790993, information which used to be wrapped in style tags.

Notice also that if you press undo twice, so that it appears that you're in the same exact position as before you pressed paste, and try again, the behavior is different and the bug goes away - but only if you moved the cursor before pressing undo twice.  Also, even if the cursor was unmoved, after the undos, putting the cursor in front of "This is some concluding body text" and pressing backspace may work a few times but then no longer has any effect; it does not remove the line break in front of it.  That seems like another bug, in the undo code (which shouldn't care where the cursor is, and apparently does not undo addition of all hidden elements, and some hidden elements break the backspace key.)

None of these behaviors are intuitive.  What is expected when pressing delete or backspace is the removal of a line break, either the one before or after the cursor for backspace and delete respectively.  To see formatting of other text change, new formatting information appear, or nothing (after two undos), is buggy behavior.

Comment 1

[WBT]

Attachment: Starter message with bug report and instructions to duplicate

Comment 2

[WBT]

Spinoffs to address issues separately: 
Bug 790993: Backspace adds formatting code and moves text unexpectedly
This bug: Delete key changes formatting in prior text instead of removing line break after
Bug 794173: Undo action does not completely undo
Bug 794177: Backspace breaks after formerly formatted text is removed

Comment 3

[Ludovic Hirlimann [:Usul]]

Are all these bugs also visible in https://www.mozilla.org/en-US/editor/midasdemo ?

Comment 4

[Ludovic Hirlimann [:Usul]]

(In reply to Ludovic Hirlimann [:Usul] from comment #3)
> Are all these bugs also visible in
> https://www.mozilla.org/en-US/editor/midasdemo ?

I meant http://www-archive.mozilla.org/editor/midasdemo/

Comment 5

[WBT]

Unfortunately, I'm unable to edit preferences files at this time, to test that.  Are there any other readers of this bug who can try it out there?

Comment 6

[Wayne Mery (:wsmwk)]

(In reply to Ludovic Hirlimann [:Usul] from comment #4)
> (In reply to Ludovic Hirlimann [:Usul] from comment #3)
> > Are all these bugs also visible in
> > https://www.mozilla.org/en-US/editor/midasdemo ?
> 
> I meant http://www-archive.mozilla.org/editor/midasdemo/

This is probably a stupid question, but what will such a test do for us?

Comment 7

[Ludovic Hirlimann [:Usul]]

(In reply to Wayne Mery (:wsmwk) from comment #6)
> (In reply to Ludovic Hirlimann [:Usul] from comment #4)
> > (In reply to Ludovic Hirlimann [:Usul] from comment #3)
> > > Are all these bugs also visible in
> > > https://www.mozilla.org/en-US/editor/midasdemo ?
> > 
> > I meant http://www-archive.mozilla.org/editor/midasdemo/
> 
> This is probably a stupid question, but what will such a test do for us?

makes the bug Core/EDItor instead of Thunderbird only :-)

Comment 8

[Wayne Mery (:wsmwk)]

WBT, can you test https://www-archive.mozilla.org/editor/midasdemo/ ?

Comment 9

[WBT]

With Thunderbird? That looks like a URL for Firefox to access.
I gave up on TB years ago due to unsolved bugs like this, and on FF after another recent episode where a forced update silently and irrevocably disabled all addons, some of which I regard as core functionality.

With this specific bug, I spent hours and hours working on specific steps to reproduce, specifically so that somebody else would be able to do the testing even if I were gone. I would prefer that the issue not be closed but that the bug-report contribution still be available to improve the software, with others able to do that testing.