[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Athos Ribeiro]

** Changed in: pixman (Ubuntu Focal)
   Status: Fix Committed => Fix Released

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Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Fix Released

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Athos Ribeiro]

** Tags removed: verification-needed
** Tags added: verification-done

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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Fix Committed

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Benjamin Gilbert]

Verified fixed with libpixman-1-0 0.38.4-0ubuntu2.

- The test program now reports "OK".
- I also installed the openslide-tools package and visually confirmed that 
"openslide-write-png CMU-1.mrxs 2 10 1 1000 1000 out.png" produces 
corrupt output with the original package and reasonable output with the fixed 
package.  CMU-1.mrxs is available from 
https://openslide.cs.cmu.edu/download/openslide-testdata/Mirax/CMU-1.zip (538 
MB).

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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Fix Committed

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Benjamin Gilbert]

** Tags removed: verification-needed-focal
** Tags added: verification-done-focal

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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Fix Committed

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Timo Aaltonen]

Hello Benjamin, or anyone else affected,

Accepted pixman into focal-proposed. The package will build now and be
available at https://launchpad.net/ubuntu/+source/pixman/0.38.4-0ubuntu2
in a few hours, and then in the -proposed repository.

Please help us by testing this new package.  See
https://wiki.ubuntu.com/Testing/EnableProposed for documentation on how
to enable and use -proposed.  Your feedback will aid us getting this
update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug,
mentioning the version of the package you tested, what testing has been
performed on the package and change the tag from verification-needed-
focal to verification-done-focal. If it does not fix the bug for you,
please add a comment stating that, and change the tag to verification-
failed-focal. In either case, without details of your testing we will
not be able to proceed.

Further information regarding the verification process can be found at
https://wiki.ubuntu.com/QATeam/PerformingSRUVerification .  Thank you in
advance for helping!

N.B. The updated package will be released to -updates after the bug(s)
fixed by this package have been verified and the package has been in
-proposed for a minimum of 7 days.

** Changed in: pixman (Ubuntu Focal)
   Status: In Progress => Fix Committed

** Tags added: verification-needed verification-needed-focal

-- 
You received this bug notification because you are a member of Ubuntu
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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Fix Committed

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Athos Ribeiro]

The first upload was rejected due to some cruft in my upload. This is a
1.0 format source package and I was dealing with some issues when
handling git (git ubuntu) being considered during the package build.
Thanks for spotting that one, Timo :) I re-uploaded the package.

-- 
You received this bug notification because you are a member of Ubuntu
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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Fix Committed

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Benjamin Gilbert]

Thanks for the help!

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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  In Progress

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Athos Ribeiro]

Thanks. Uploaded!

** Changed in: pixman (Ubuntu Focal)
   Status: Triaged => In Progress

** Changed in: pixman (Ubuntu Focal)
 Assignee: (unassigned) => Athos Ribeiro (athos-ribeiro)

-- 
You received this bug notification because you are a member of Ubuntu
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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  In Progress

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Benjamin Gilbert]

Yup, the test program fails without the packages from the PPA and
succeeds once they're installed.

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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Triaged

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+subscriptions


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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Athos Ribeiro]

Thanks, Benjamin!

I uploaded a patched package to the following PPA:
https://launchpad.net/~athos-ribeiro/+archive/ubuntu/lp1988796-pixman

Please, test it to ensure everything works as expected before we proceed
with the SRU process here.

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https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Triaged

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Athos Ribeiro]

** Description changed:

+ [ Impact ]
+ 
+ OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering backend,
+ always with CAIRO_OPERATOR_SATURATE and sometimes with subpixel
+ positioning (when reading certain file formats), and Cairo in turn
+ invokes this code. As a result, some slides incorrectly render with
+ large blank spaces and with some pixels rendered on top of other pixels.
+ This effectively makes OpenSlide unusable for several of the file
+ formats it supports. No workaround is believed possible within the
+ OpenSlide codebase.
+ 
+ [ Test Plan ]
+ 
+ Compile and run the pixman.c test program uploaded to this bug. It
+ should report "OK".
+ 
+ [ Where problems could occur ]
+ 
+ Problems would show up as incorrect pixel output from software that
+ renders via Cairo or pixman.
+ 
+ [ Other Info ]
+ 
+ While I'm not a pixman expert, it appears that the change should only
+ affect the broken code path, and it seems unlikely that anything else
+ depends on the incorrect math fixed by this patch. This bug hasn't
+ previously been reported in Ubuntu, which may imply that this code path
+ is not exercised by other packages in the distro.
+ 
+ The affected source file has had no further commits upstream since this
+ patch was applied in April 2019, and some basic commit grepping didn't
+ turn up any followup fixes elsewhere in the tree.
+ 
+ [ Original message ]
+ 
  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some circumstances.
  This can be triggered by the use of cairo with CAIRO_OPERATOR_SATURATE
  and subpixel positioning, and causes OpenSlide 
  to produce incorrect output.
  
  The attached test program will print "Failed" if the bug exists, or "OK"
  if it doesn't.
  
  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which is
  in pixman 0.40.0.
  
  See https://github.com/openslide/openslide/issues/278 for more context.

** Also affects: pixman (Ubuntu Focal)
   Importance: Undecided
   Status: New

** Changed in: pixman (Ubuntu)
   Status: New => Fix Released

** Changed in: pixman (Ubuntu Focal)
   Status: New => Triaged

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to pixman in Ubuntu.
https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  Fix Released
Status in pixman source package in Focal:
  Triaged

Bug description:
  [ Impact ]

  OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering
  backend, always with CAIRO_OPERATOR_SATURATE and sometimes with
  subpixel positioning (when reading certain file formats), and Cairo in
  turn invokes this code. As a result, some slides incorrectly render
  with large blank spaces and with some pixels rendered on top of other
  pixels. This effectively makes OpenSlide unusable for several of the
  file formats it supports. No workaround is believed possible within
  the OpenSlide codebase.

  [ Test Plan ]

  Compile and run the pixman.c test program uploaded to this bug. It
  should report "OK".

  [ Where problems could occur ]

  Problems would show up as incorrect pixel output from software that
  renders via Cairo or pixman.

  [ Other Info ]

  While I'm not a pixman expert, it appears that the change should only
  affect the broken code path, and it seems unlikely that anything else
  depends on the incorrect math fixed by this patch. This bug hasn't
  previously been reported in Ubuntu, which may imply that this code
  path is not exercised by other packages in the distro.

  The affected source file has had no further commits upstream since
  this patch was applied in April 2019, and some basic commit grepping
  didn't turn up any followup fixes elsewhere in the tree.

  [ Original message ]

  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Benjamin Gilbert]

** Patch added: "Updated debdiff with dep3 headers added"
   
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+attachment/5623244/+files/2-0.38.4-0ubuntu2.debdiff

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to pixman in Ubuntu.
https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  New

Bug description:
  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+subscriptions


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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Benjamin Gilbert]

[ Impact ]

OpenSlide (libopenslide0 in Ubuntu) uses Cairo as its rendering backend,
always with CAIRO_OPERATOR_SATURATE and sometimes with subpixel
positioning (when reading certain file formats), and Cairo in turn
invokes this code.  As a result, some slides incorrectly render with
large blank spaces and with some pixels rendered on top of other pixels.
This effectively makes OpenSlide unusable for several of the file
formats it supports.  No workaround is believed possible within the
OpenSlide codebase.

[ Test Plan ]

Compile and run the pixman.c test program uploaded to this bug.  It
should report "OK".

[ Where problems could occur ]

Problems would show up as incorrect pixel output from software that
renders via Cairo or pixman.

[ Other Info ]

While I'm not a pixman expert, it appears that the change should only
affect the broken code path, and it seems unlikely that anything else
depends on the incorrect math fixed by this patch.  This bug hasn't
previously been reported in Ubuntu, which may imply that this code path
is not exercised by other packages in the distro.

The affected source file has had no further commits upstream since this
patch was applied in April 2019, and some basic commit grepping didn't
turn up any followup fixes elsewhere in the tree.

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to pixman in Ubuntu.
https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  New

Bug description:
  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+subscriptions


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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Athos Ribeiro]

Hi Benjamin,

Thanks for taking the time to provide this fix!

Would you be willing to file the SRU template [1] for this bug so we can
proceed here?

It would also be nice to add dep3 headers [2] to that patch.

[1] https://wiki.ubuntu.com/StableReleaseUpdates#SRU_Bug_Template
[2] https://dep-team.pages.debian.net/deps/dep3/

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to pixman in Ubuntu.
https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  New

Bug description:
  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+subscriptions


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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Ubuntu Foundations Team Bug Bot]

The attachment "1-0.38.4-0ubuntu2.debdiff" seems to be a debdiff.  The
ubuntu-sponsors team has been subscribed to the bug report so that they
can review and hopefully sponsor the debdiff.  If the attachment isn't a
patch, please remove the "patch" flag from the attachment, remove the
"patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe
the team.

[This is an automated message performed by a Launchpad user owned by
~brian-murray, for any issue please contact him.]

** Tags added: patch

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to pixman in Ubuntu.
https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  New

Bug description:
  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+subscriptions


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[Touch-packages] [Bug 1988796] Re: Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with subpixel positioning

[Benjamin Gilbert]

This is a debdiff for the focal version of pixman, 0.38.4-0ubuntu1.
I've built and installed this and verified that the test case now
reports "OK".

** Patch added: "1-0.38.4-0ubuntu2.debdiff"
   
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+attachment/5613889/+files/1-0.38.4-0ubuntu2.debdiff

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to pixman in Ubuntu.
https://bugs.launchpad.net/bugs/1988796

Title:
  Incorrect rendering triggered by cairo CAIRO_OPERATOR_SATURATE with
  subpixel positioning

Status in pixman package in Ubuntu:
  New

Bug description:
  pixman 0.38.4-0ubuntu1 in focal (and actually pixman 0.38.x generally)
  has a regression that causes incorrect rendering in some
  circumstances.  This can be triggered by the use of cairo with
  CAIRO_OPERATOR_SATURATE and subpixel positioning, and causes OpenSlide
   to produce incorrect output.

  The attached test program will print "Failed" if the bug exists, or
  "OK" if it doesn't.

  This is fixed upstream in
  https://gitlab.freedesktop.org/pixman/pixman/-/commit/8256c235, which
  is in pixman 0.40.0.

  See https://github.com/openslide/openslide/issues/278 for more
  context.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/pixman/+bug/1988796/+subscriptions


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