16584 - PRE not working as it should - some blank lines collapse

Status: VERIFIED FIXED

(Core :: Layout, defect, P3)

Description

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

DESCRIPTION:
Many (but not all) blank lines are being collapsed in PRE elements.  Perhaps
this has something to do with some line box work??

STEPS TO REPRODUCE:
 * load http://bugzilla.mozilla.org/show_bug.cgi?id=12272 (or probably this bug
too) in apprunner and in NN 4.x and compare the positions of blank lines in the
comments (which are in a big PRE)

EXPECTED RESULTS:
 * the same

ACTUAL RESULTS:
 * many blank lines missing in Mozilla

DOES NOT WORK CORRECTLY ON:
 * Linux, apprunner, 1999-10-15-11-M11

WORKS CORRECTLY ON:
 * NN 4.x

ADDITIONAL INFORMATION:
I think this is a regression.  I could check when it started if you want...

Comment 1

[kipp]

It's a parser bug. If you dump the content model you will see that N newlines in
a row are turned into N-1 by the parser.

Comment 2

[kipp]

Attachment: a reduced test case from the bugs own bugzilla page :-)

Comment 3

[Sean Richardson]

Also affects recent M11 on Windows NT, including 1999-10-15-11-M11,
in every bug report I've viewed.

If this is a parser problem, must be XP. Marking OS "All".

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Are you sure this is a parser bug and not a Necko bug?  I'm seeing similar
problems on http://asp1.sbs.ohio-state.edu/text/severe/atltrop/ , but I can't
replicate them if I save the page to a local file.

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

I'm also seeing this problem on text files, e.g.,
http://asp1.sbs.ohio-state.edu/text/severe/tropical/ABNT20.KNHC .  I think this
is likely Necko, not parser.

Comment 6

[rickg]

I'm not sure this is a parser bug either. It certainly doesn't show up on NT
using the testcase.

Comment 7

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

If you

Comment 8

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

What I tried to say was:

If you do not see these problems on NT, then perhaps it is a Linux-specific
Necko bug.  There is definitely something going on here, and it's been happening
for a while.

Comment 9

[Sean Richardson]

Uh, Oh.
DOES NOT WORK CORRECTLY ON:
Windows NT, mozilla.exe, 1999-10-17-08-M11 build.
Windows NT, apprunner.exe, M10 build.
No "blank" lines visible in original testcase.

WORKS CORRECTLY ON:
Navigator 4.7
"Blank" lines visible where they belong.

Tried to test http://asp1.sbs.ohio-state.edu/text/severe/tropical/ABNT20.KNHC -
couldn't because of bug 16697.

In the testcase, the "blank lines" show up as "0D0A0D0A" in a hex editor
Have tried pages where the "blank lines" show up as "0A0A" in a hex editor,
(in both cases in a PRE to sidestep Bug 16697), and everything is the same.

rickg, what build were you using? I've never seen the testcase display
properly on any Win32 build of Mozilla, on NT or 95. That's over at least
10 builds since I became aware of this bug.

Comment 10

[rickg]

I found the bug, and I've fixed it for windows. The reason it was difficult to
diagnose was because it only happens on network URLS. If you take the test case
(given) and save it to a file, this bug disappears.

I'll confirm that this works on mac/linux, then I'll check in.

Comment 11

[rickg]

Fixed (and verified) on mac/linux/pc. I've also added this as a regression test.
If you see other oddities, send'em my way.

Comment 12

[Chris Petersen]

With the attached testcase provided, this problem appears to be fixed in the Oct
21 build.