Using Mercurial

This document is outdated. Please see Mercurial For Mozillians.

Please refer to Mercurial For Mozillians at ReadTheDocs for current best-practices around Mercurial, including many helpful extra tools and guidelines that make using Mercurial fast and easy. This document describes techniques and practices like mercurial queues which are no longer recommended.

 

Installing and configuring Mercurial

See Installing Mercurial. Even if you already have Mercurial installed, make sure

  • you're running the most recent version, and
  • it's configured appropriately (see the instructions on the installation page).

How can I...

How can I check out Mozilla?

To clone the main development repository for Gecko and Firefox use:

hg clone https://hg.mozilla.org/mozilla-central/ src
cd src

For the list of other repositories see Getting Mozilla Source Code Using Mercurial.

How can I edit and update files?

You can randomly edit files in the working directory, just like with CVS.

The common command to update a tree is:

hg pull -u

It is not possible to update only one directory; you have to update the entire tree.

How can I diff and patch files?

  • hg diff diffs the entire tree by default. Use hg diff <dir> to diff only the given directory. Don't forget to hg add any new files you are adding before generating the patch.
  • If you are changing binary files or renaming files you may want to use git style patches with hg diff -g to retain that sort of information in the patch.
  • When applying a patch generated by Mercurial, use patch -p1, not patch -p0. (This is due to a quirk of Mercurial diff output—it refers to fictional "a" and "b" directories. Don't ask.).
  • If you have a git style patch with renames and/or binary changes you can use hg import --no-commit to apply the patch to your tree.
  • If you have it, git-apply can also be used to apply patches. It can handle most forms of Mercurial diff output, but it won't automatically tell Mercurial about added, copied, removed or renamed files, and it cannot reverse binary changes (except to remove added binary files).

Preferred diff options are hg diff -p -U 8 which includes 8 lines of context and shows the relevant function for the block. You can make these options default in the Mercurial configuration file.

How can I generate a patch for somebody else to check-in for me?

The interactive setup wizard can guide you through the process of configuring Mercurial to submit commits to Mozilla:

./mach mercurial-setup

In most cases, commits should be submitted via MozReview:

hg push review

See the MozReview User Guide for more.

If you need to attach a commit to a Bugzilla bug, the bzexport Mercurial extension should be used. This extension will be enabled by mach mercurial-setup if you say you will use Bugzilla to submit patches. To attach a commit to a bug:

hg bzexport

To manually generate a patch file and attach it to Bugzilla:

hg export . > my-change.patch

Using `hg export` is extremely brittle, as it may not format commits properly. You are highly encouraged to use MozReview.

Commit Message Conventions

A good sample simple commit message looks like:

Bug 123456 - Change this thing to work better by doing something. r=reviewers

The text of the message should be what you did to fix the bug, not a description of what the bug was. You can leave off the r=reviewers part if you're not sure who is going to review your bug; the person who does the final check-in of the patch will make sure it's added. You can edit the commit message of the current at any time using hg commit --amend or hg histedit.

If it is not obvious why this change is appropriate, then explain why in the commit message.  If this does not fit on one line, then leave a blank line and add further lines for more detail and/or reasoning.

A quick way to generate a patch is to actually commit changes to your local Mercurial repository, then generate a patch from those local commits.  Once you've cloned the necessary Mozilla source code, ensure that your name and e-mail are set in your hgrc file:
[ui]
username = John Doe <johndoe@mydomain.com>
As would be expected, this will output the changes in the form of a patch file named mypatch.diff, which can then be submitted to Bugzilla.  If you need to make further changes to your patch, you can back out that last commit, leaving the changes in place, using:
hg strip --keep -r .
That will back out the last 1 commit; if you need to back out the last 2 or 3 commits, use:
hg strip --keep -r .~1   # 2 commits
hg strip --keep -r .~2   # 3 commits

Then make the further changes you need, use hg commit again to commit them locally, and follow the above procedure to generate the new patch.

I'm all used to Git, but how can I provide Mercurial-ready patches ?

First, create a Git patch using a command like this:

$ git format-patch -k -p fx-team

in your working branch to produce a patch against the fx-team branch. The "-k" option prevents Git from adding a [PATCH] prefix to the commit message, and the "-p" option prevents Git from adding a diffstat to the start of the patch. Note that this command creates one patch per commit.

Next, install and set up moz-git-tools.

Now you can use the git-patch-to-hg-patch tool to convert from Git generated patches to Mercurial-ready ones:

$ git-patch-to-hg-patch YourGitGeneratedPatch.patch

How do I check stuff in?

Required configuration

Before committing any changes, add these lines to your ~/.hgrc file:

[ui]
username = Your Name <your.email@example.com>

To push to mozilla-central and other mozilla-hosted repositories you need committer access, and you must edit the file (your-local-hg-root)/.hg/hgrc (note, this is NOT your ~/.hgrc) to add these lines. Except in case of critical bug fix, every patches must land in mozilla-inbound, fx-team or b2g-inbound. They are merged to mozilla-central about once per day.

# General usage
[paths]
default = http://hg.mozilla.org/mozilla-central/
default-push = ssh://hg.mozilla.org/integration/mozilla-inbound/
# Firefox front-end work
[paths]
default = http://hg.mozilla.org/mozilla-central/
default-push = ssh://hg.mozilla.org/integration/fx-team/
# B2G
[paths]
default = http://hg.mozilla.org/mozilla-central/
default-push = ssh://hg.mozilla.org/integration/b2g-inbound/

You also have to tell ssh what username to use when connecting to hg.mozilla.org. This should be the username associated with your Mozilla LDAP account. You can do this either by making the default-push path above more complicated (user@host.name@hg.mozilla.org) or by adding lines to your ~/.ssh/config :

Host hg.mozilla.org
User user@host.domain

If at any point you need to change or add a ssh public key to the LDAP account, self-service is at https://login.mozilla.com/.

Check what you're going to commit

Next, to check if you're really committing what you want to commit (especially important when doing merges or other trickier commits):

hg status
hg diff

status shows the files that have changed in your working directory compared to what's in your repository (the parent revisions, which you can see by using hg parents). hg diff shows the actual changes in those files, as unified diffs. You can add a -U8 option to see more context.

Commit to the local repository

As the next step, you will commit your changes to your local repository:

hg commit

This commits every change reported by hg status. You can limit the commit to specific files or directories using hg commit filenames. You can commit on behalf of someone else using hg commit -u "Someone Else <someone@example.com>". See hg help commit for more details.

To add new files to the repository and to remove obsolete ones use

hg addremove

Check what you're going to push

Before you push, you likely want to check what changesets will be pushed. You can do this using the outgoing command:

hg outgoing

This will give you a list of changesets that will be pushed to the default remote repository. Add a repository argument to see outgoing changesets for another repository.

Push to the central repository

To push those changes upstream to the central repository:

hg push

Preventing accidental pushes

To prevent accidental pushes you can add the following hook in your ~/.hgrc file:

[hooks]
pre-push = printf 'Are you sure you want to push to remote? (y/n): '; read R; [ x"$R" == "xy" ]

This will cause the push command to request confirmation each time it is invoked and abort if the user types anything but y.

How do I deal with "abort: push creates new remote heads!"?

Whatever you do, don't do 'push -f' like the message suggests. (It'll probably fail anyway, but don't try it.)

Someone pushed new commits upstream since your last pull. You then committed your patch locally and are trying to push that commit upstream; that upstream has a different tip commit that you started from.

  YOU ---> o  9123b7791b52 - Kaitlin Jones <kaitlin@example.net> - Bug 123456 - Trebled fromps (r=gavin)
           | 
TRUNK ---> | o  306726089e22 - Robert Longson <longsonr@example.com> - Bug 437448. New-style nsSVGString
           | | 
           | o  ba9b9a7c52a5 - Robert Longson <longsonr@example.com> - Bug 437448. New-style nsSVGString
           |/
           o  f8f4360bf155 - Robert O'Callahan <robert@example.org> - Bug 421436. Remove hack that gives

There are three things you can do. In all cases, you are strongly encouraged to take steps to back up your patch (perhaps by obtaining a diff: hg log -p -r 12345 to show the patch for rev 12345).

Using hg merge

Run hg pull, then hg merge. If there are any merge conflicts, hg will open a merge program to try to help you resolve them manually. (If you fail to make sense of the merge tool, that's OK.  Just close it; hg will detect that the conflicts weren't all resolved and spit out some hg update -C commands that you can use to undo and then retry the busted merge.)

Even if there were no conflicts, you have to commit the merge: hg commit -m "Merge bug 123456".

  YOU ---> o 1fe7659c29a9 - Kaitlin Jones <kaitlin@example.net> - Merge bug 123456.
           |\
           o | 9123b7791b52 - Kaitlin Jones <kaitlin@example.net> - Bug 123456 - Trebled fromps (r=gavin)
           | |
TRUNK ---> | o  306726089e22 - Robert Longson <longsonr@example.com> - Bug 437448. New-style nsSVGString
           | | 
           | o  ba9b9a7c52a5 - Robert Longson <longsonr@example.com> - Bug 437448. New-style nsSVGString
           |/
           o  f8f4360bf155 - Robert O'Callahan <robert@example.org> - Bug 421436. Remove hack that gives

Now you can hg push as normal.

This leaves a merge commit in the log, which some people find annoying, so it's usually better to avoid this solution.

If you decide to use this method, it is advantageous to enable the Mercurial fetch extension (by means of a fetch = line in the [extensions] section of your <repository>/.hg/hgrc or your $HOME/.hgrc file) so you can do the pull + merge + commit sequence in one step (assuming no merge conflicts) by using the hg fetch command.

Using hg rebase

This is the simplest and easiest way to deal with the problem. You can rebase your local changesets on top of the tip using the rebase extension. To do this, simply enable the extension by adding this to the following section of your .hgrc:

[extensions]
rebase =

Now, type hg pull --rebase to pull and rebase your local changesets at the same time. More details and options can be found at the Mercurial wiki.

If you have conflicting changes, you'll be thrown into your preferred merge tool.

Note: If you had done a normal hg pull without --rebase after your hg commit, you will have to first undo that by doing hg rollback. Only the very last action can be undone, so if you did anything else after the hg pull, you're out of luck.
Note: If you have local changes, hg pull --rebase (just like hg merge) will refuse to work, so you'll have to revert your local changes first:
hg diff > old.diff
hg revert .
hg pull --rebase
hg push
patch -p 1 -i old.diff
rm old.diff

How do I see what these commands will do before I do them?

If you want to see what hg commit will commit, run hg diff first.

If you want to see what hg push will push, run hg outgoing first.

If you want to see what hg pull will pull, run hg incoming first.

These pairs of commands all take similar arguments, for good reason. These are a good idea to use all the time when you're learning mercurial. And even once you're an expert, always doing outgoing before push is a good idea.

How can I customize the format of the patches Mercurial creates?

Edit your ~/.hgrc file and add some lines like these:

[defaults]
diff=-U 8 -p
qdiff=-U 8
#for Mercurial 1.1 use:
#qdiff=-U 8 -p
[diff]
git=true

The [defaults] section affects the default output of the hg diff and hg qdiff commands. The options behave the same as they would on the command line. Try hg help diff for more info.

The [diff] section affects all patches generated by Mercurial, even hg export and those generated for Mercurial's internal use. You need to be a lot more careful with this, but git=true is recommended. Without it, Mercurial cannot diff binary files and does not track the execute mode bit.  You may want to add showfunc=true here to get diffs that show the function being changed in each hunk, and you may want to add unified=8 to make all diffs have 8 lines of context.

How do I get a diff -w?

There is a known issue where hg diff -w doesn't work.

To get around this add the following to your ~/.hgrc file, editing existing sections where applicable:

[extensions]
hgext.extdiff =
[extdiff]
cmd.diffw = diff
opts.diffw = -w -r -N -p -U 8

You can, of course, add your other favourite diff options to opts.diffw. Once you've added this, you will now have a new hg command, hg diffw.

How do I generate a bundle?

Sometimes the tree will be under sheriff control, and they will specifically ask for a bundle.  If you don't have sufficient rights to push to mozilla-central, you might also generate bundles and attach them to bugs when you add checkin-needed to a bug after it has the necessary reviews and approval.

Creating a bundle is quite simple.  Once you have your changes all done, commit them to your local repository.  You can also commit more than one changeset.  Once you have everything committed, instead of pushing you'll run hg bundle:

hg bundle outputfile.hg

By default, hg bundle will bundle everything that hg outgoing would display (and what you would push with hg push).  You can limit how far forward you want to bundle as well by specifying a revision with -r.  That will take all changes up until that revision.

Backing out changes

Reverting the whole tree to a known-good revision

It's easy, like using a sledgehammer is easy. But this is usually overkill.

$ hg pull -u
$ hg revert --all -r a0193d83c208       # use your known-good revision id here
$ hg commit                             # be kind, include the revision id in your commit message
$ hg push

There's a more precise alternative:

Backing out a single changeset

Suppose changeset f8f4360bf155 broke something.

$ hg pull -u
$ hg backout f8f4360bf155               # use the revision id of the bad change here

This creates and commits a new changeset that reverts all the changes in that revision.

If you see this message:

the backout changeset is a new head - do not forget to merge

That means you need to merge, because your history now looks like this:

  YOU ---> o  9123b7791b52 - Kaitlin Jones <kaitlin@example.net> - Backed out changeset f8f4360bf155
           | 
TRUNK ---> | o  4e5bfb83643f - Simon Montagu <smontagu@example.org> - imported patch 435856
           | | 
           | o  6ee23de41631 - Phil Ringnalda <philringnalda@example.com> - Bug 438526 - Opening links w
           | | 
           | o  22baa05d0e8a - Robert O'Callahan <robert@example.org> - Remove DOM testcase from exclusi
           | | 
           | o  c1aec2094f7e - Robert Longson <longsonr@example.com> - Bug 437448. New-style nsSVGString
           | | 
           | o  306726089e22 - Robert Longson <longsonr@example.com> - Bug 437448. New-style nsSVGString
           | | 
           | o  ba9b9a7c52a5 - Robert Longson <longsonr@example.com> - Bug 437448. New-style nsSVGString
           |/
           o  f8f4360bf155 - Robert O'Callahan <robert@example.org> - Bug 421436. Remove hack that gives
           |
           ⋮ (the past)

Your backout changeset is based on an old revision. It doesn't contain more recent changes.

Handle this like any other merge. If you've never done a merge before, get help. (It could be trivial or it could be a huge headache. There's plenty about merging elsewhere in this FAQ.)

Backing out multiple changesets that are not at tip

Your push of many changesets was bad, but you didn't find out until after a lot of subsequent activity. You want to back out the bad but keep the probably-good changesets from the subsequent activity.

NB: this is hard, error-prone, and will likely b0rk your local tree if you mess up. If in doubt, ask someone else to do it for you.

What one would really like to do is

hg backout --from-rev $FIRST_BAD --to-rev $LAST_BAD

or, if local hg could access pushlog

hg backout --push $LAST_BAD

but, since hg can't do either (yet), we're stuck. What we'll do instead is travel back in hg-time to the last bad cset, revert all changes between last-bad and last-good, then merge that reversion to the current tip. Your tree might look like

 MERGE_TO ---> @  c6abfc89215a - Chris Pearce <chris@pearce.org.nz> - Bug 485288 - Replace all usage of video  autobuffer attribute with preload=auto. a=test-fix
               |
               o  d6e8fddeb95b - Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Disable test_preload_actions.html case 9 until bug 568402 is fixed. a=test-fix
               |
               o  571d2664ead0 - Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Don't show throbber on video controls if we're not loading a resource. r=dolske a=blocking2.0
               |
               o  3f7dfabab5e4 - Rich Dougherty <rich@rd.gen.nz>, Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Replace HTMLMediaElement.autobuffer attribute with 'preload'. r=roc a=blocking2.0
               |
               o  d7d9cf4ab76a - Chris Pearce <chris@pearce.org.nz> - Bug 519897 - Supported indexed Ogg files. r=doublec
               |
               o    2a0e5811ece9 - Chris Pearce <chris@pearce.org.nz> - Commit merge of backout of 66dcf25705f9. a=backout
               |\
               | o  958a30df30dd - Chris Pearce <chris@pearce.org.nz> - Backed out changeset 66dcf25705f9
               | |
               o |  6eead86e13dd - Michael Wu <mwu@mozilla.com> - Bug 556644 - Yet another removed-files.in update, r=rs a=blocking-beta5
               | |
               o |  69c6ce104f45 - Chris Jones <jones.chris.g@gmail.com> - Bug 588216: Avoid race between IO-thread loop->PostTask() and main-thread loop->SetNestableTasksAllowed() that led to Tasks being ignored. r=bent
               | |
               o |  73899b33ca4b - Ben Turner <bent.mozilla@gmail.com> - Bug 576716 - 'Crash [@ TypedArrayTemplate<int>::init] or [@ TypedArrayTemplate<int>::create]'. Adding a test, r=vlad a=blocker
               | |
               o |  3bd62d459019 - Mark Banner <bugzilla@standard8.plus.com> - Follow up to bug 587984 bustage fix for l10n repacks. r=Pike,ted,a=bustage-fix
               | |
               o |  e1ca9091e5a6 - Benjamin Stover <webapps@stechz.com> - Bug 575731: Make test more stable in the face of various themes. r,a=sicking
               | |
               o |  bb200e1f52b4 - Jonas Sicking <jonas@sicking.cc> - Bug 550959: Require version 2.5 of python. r=ted a=sicking
               | |
               o |  992491c618de - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (12/12): fix assertions in nsStyleAnimation triggered by part 3.  r=dbaron  a2.0=dbaron
               | |
               o |  2f078585a0f6 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (11/12): Make all assertions fatal in Declaration.h, Declaration.cpp, nsCSSDataBlock.h, nsCSSDataBlock.cpp, nsCSSValue.h, nsCSSValue.cpp, nsCSSProps.h, and nsCSSProps.cpp.  r=dbaron  a2.0=dbaron
               | |
               o |  5a9bd15fd7a8 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (10/12): Don't directly manipulate the contents of mTempData in the CSS parser.  r=dbaron  a2.0=dbaron
               | |
               o |  4bb2e0074aeb - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (9/12): Add an AddLonghandProperty method to nsCSSExpandedDataBlock.  r=dbaron  a2.0=dbaron
               | |
               o |  659a0864e035 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (8/12): remove the last MoveValue call from the CSS parser.  r=dbaron  a2.0=dbaron
               | |
               o |  980f0170d982 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (7/12): cleanup pass on css/Declaration.{h,cpp} and nsCSSDataBlock.{h,cpp}.  r=dbaron  a2.0=dbaron
               | |
               o |  f09c1638d3c1 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (6/12): remove vestiges of nsCSSType.  r=dbaron  a2.0=dbaron
               | |
               o |  b88472b0af90 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (5/12): eliminate ValueList as a storage type.  r=dbaron  a2.0=dbaron
               | |
               o |  a3e21759b570 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (4/12): eliminate ValuePairList as a storage type.  r=dbaron  a2.0=dbaron
               | |
               o |  ed89c9e297ab - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (3/12): eliminate Rect as a storage type.  r=dbaron  a2.0=dbaron
               | |
               o |  4fc85e572c38 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (2/12): eliminate ValuePair as a storage type.  r=dbaron  a2.0=dbaron
               | |
               o |  301875d4f9b6 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (1/12): Move all the CSS 'storage types' (rect, value pair, etc) to nsCSSValue.h and their code to nsCSSValue.cpp.  r=dbaron  a2.0=dbaron
               | |
 LAST_BAD ---> o |  90ad165ae21b - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part i: Use nsIWidget::CreateChild in nsIView::CreateWidget* (where possible). r=roc a=blocking-fennecb1
               | |
               o |  037a5d6b376a - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part h: Add an nsIWidget::CreateChild interface to sweep (relevant to this bug) code dealing with native widgets under the widget/src/* rug. sr=roc
               | |
               o |  f1af117d4598 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part g: Split nsIView::CreateWidget into CreateWidget, CreateWidgetForParent, and CreateWidgetForPopup in preparation of eliminating IIDs here. sr=roc
               | |
               o |  5bf0b315a5aa - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part f: Split out window initialization code in preparation for multiple CreateWidget* methods. r=roc
               | |
               o |  353da995af6f - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part e: Simplify the logic for creating popup widgets. r=roc
               | |
               o |  7735c00eabe9 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part d: Simplify nsView::LoadWidget and return early if it fails. r=roc
               | |
               o |  7b17bcefb174 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part c: Initialize default widget init data earlier so that it's always available. r=roc
               | |
               o |  c5945b6a97ed - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part b: Remove nsIDeviceContext::SupportsNativeWidgets because it's not used meaningfully, and will be confusing in content processes. sr=roc
               | |
               o |  5452db293694 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part a: Add nsIView::Impl() and nsView::CreateWidget() to get rid of |static_cast<nsview*>(this)|. r=roc
               | |
               o |  9407827b5166 - Chris Jones <jones.chris.g@gmail.com> - Bug 582075, part 0.5: Add support for aInitData=NULL to the Windows nsWindow implementation. r=dougt
               | |
               o |  88a279b64473 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part 0: Log the repaint region bounding rect in DumpPaintEvent. r=roc
               | |
               o |  cebb111fbfc4 - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 3: Remove nsSVGUtils::GetThebesComputationalSurface and use gfxPlatform::ScreenReferenceSurface instead. r=jwatt
               | |
               o |  7b3726c3a580 - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 2: Change nsIPresShell::CreateRenderingContext to GetReferenceRenderingContext, that uses the shared 1x1 surface, and use it all over the place. r=mats,sr=dbaron
               | |
FIRST_BAD ---> o |  b3e968d831ec - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 1: Create a single static 1x1 surface in gfxPlatform that can be used to create contexts for text measurement etc. r=vlad
               | |
LAST_GOOD ---> o |  55ef0e0529bc - Mounir Lamouri <mounir.lamouri@gmail.com> - Bug 506554 - Implement the CSS3 pseudo-classes :required and :optional for HTML. r=sicking sr=bz a2.0=blocking
               | |
</int></int>

We want to erase all changes between $FIRST_BAD and $LAST_BAD, then merge to $MERGE_TO

$ MERGE_TO="c6abfc89215a"
$ LAST_BAD="90ad165ae21b"
$ LAST_GOOD="55ef0e0529bc"
$ hg up -r $LAST_BAD
90 files updated, 0 files merged, 4 files removed, 0 files unresolved

We just traveled back in time to the last cset we want to nuke. Now we'll revert the changes between $FIRST_BAD and $LAST_BAD.

$ hg revert --all --no-backup -r $LAST_GOOD
reverting accessible/src/msaa/nsTextAccessibleWrap.cpp
reverting content/svg/content/src/SVGMotionSMILPathUtils.h
reverting content/svg/content/src/nsSVGPathElement.cpp
reverting gfx/src/nsIDeviceContext.h
reverting gfx/src/thebes/nsThebesDeviceContext.cpp
reverting gfx/src/thebes/nsThebesDeviceContext.h
reverting gfx/thebes/gfxPlatform.cpp
reverting gfx/thebes/gfxPlatform.h
reverting layout/base/nsCSSFrameConstructor.cpp
reverting layout/base/nsDocumentViewer.cpp
reverting layout/base/nsIPresShell.h
reverting layout/base/nsPresShell.cpp
reverting layout/build/nsLayoutStatics.cpp
reverting layout/generic/nsFrameFrame.cpp
reverting layout/generic/nsObjectFrame.cpp
reverting layout/generic/nsSimplePageSequence.cpp
reverting layout/generic/nsTextFrameThebes.cpp
reverting layout/inspector/src/inFlasher.cpp
reverting layout/printing/nsPrintEngine.cpp
reverting layout/svg/base/src/nsSVGForeignObjectFrame.cpp
reverting layout/svg/base/src/nsSVGGlyphFrame.cpp
reverting layout/svg/base/src/nsSVGImageFrame.cpp
reverting layout/svg/base/src/nsSVGPathGeometryFrame.cpp
reverting layout/svg/base/src/nsSVGUtils.cpp
reverting layout/svg/base/src/nsSVGUtils.h
reverting layout/xul/base/src/nsMenuPopupFrame.cpp
reverting layout/xul/base/src/nsSplitterFrame.cpp
reverting layout/xul/base/src/tree/src/nsTreeBodyFrame.cpp
reverting view/public/nsIView.h
reverting view/src/nsView.cpp
reverting view/src/nsView.h
reverting widget/public/nsIWidget.h
reverting widget/src/beos/nsWindow.h
reverting widget/src/cocoa/nsChildView.h
reverting widget/src/cocoa/nsCocoaWindow.h
reverting widget/src/windows/nsWindow.cpp
reverting widget/src/xpwidgets/nsBaseWidget.cpp
reverting widget/src/xpwidgets/nsBaseWidget.h
$ hg commit -m 'Back out bug 585817 and bug 582057'
created new head

After committing the reversion, we now have a new head that doesn't include the probably-good changes after $LAST_BAD.

@  1767c1fb9418 - Chris Jones <jones.chris.g@gmail.com> - Back out bug 585817 and bug 582057
|
| o  c6abfc89215a - Chris Pearce <chris@pearce.org.nz> - Bug 485288 - Replace all usage of video  autobuffer attribute with preload=auto. a=test-fix
| |
| o  d6e8fddeb95b - Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Disable test_preload_actions.html case 9 until bug 568402 is fixed. a=test-fix
| |
| o  571d2664ead0 - Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Don't show throbber on video controls if we're not loading a resource. r=dolske a=blocking2.0
| |
| o  3f7dfabab5e4 - Rich Dougherty <rich@rd.gen.nz>, Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Replace HTMLMediaElement.autobuffer attribute with 'preload'. r=roc a=blocking2.0
| |
| o  d7d9cf4ab76a - Chris Pearce <chris@pearce.org.nz> - Bug 519897 - Supported indexed Ogg files. r=doublec
| |
| o    2a0e5811ece9 - Chris Pearce <chris@pearce.org.nz> - Commit merge of backout of 66dcf25705f9. a=backout
| |\
| | o  958a30df30dd - Chris Pearce <chris@pearce.org.nz> - Backed out changeset 66dcf25705f9
| | |
| o |  6eead86e13dd - Michael Wu <mwu@mozilla.com> - Bug 556644 - Yet another removed-files.in update, r=rs a=blocking-beta5
| | |
| o |  69c6ce104f45 - Chris Jones <jones.chris.g@gmail.com> - Bug 588216: Avoid race between IO-thread loop->PostTask() and main-thread loop->SetNestableTasksAllowed() that led to Tasks being ignored. r=bent
| | |
| o |  73899b33ca4b - Ben Turner <bent.mozilla@gmail.com> - Bug 576716 - 'Crash [@ TypedArrayTemplate<int>::init] or [@ TypedArrayTemplate<int>::create]'. Adding a test, r=vlad a=blocker
| | |
| o |  3bd62d459019 - Mark Banner <bugzilla@standard8.plus.com> - Follow up to bug 587984 bustage fix for l10n repacks. r=Pike,ted,a=bustage-fix
| | |
| o |  e1ca9091e5a6 - Benjamin Stover <webapps@stechz.com> - Bug 575731: Make test more stable in the face of various themes. r,a=sicking
| | |
| o |  bb200e1f52b4 - Jonas Sicking <jonas@sicking.cc> - Bug 550959: Require version 2.5 of python. r=ted a=sicking
| | |
| o |  992491c618de - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (12/12): fix assertions in nsStyleAnimation triggered by part 3.  r=dbaron  a2.0=dbaron
| | |
| o |  2f078585a0f6 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (11/12): Make all assertions fatal in Declaration.h, Declaration.cpp, nsCSSDataBlock.h, nsCSSDataBlock.cpp, nsCSSValue.h, nsCSSValue.cpp, nsCSSProps.h, and nsCSSProps.cpp.  r=dbaron  a2.0=dbaron
| | |
| o |  5a9bd15fd7a8 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (10/12): Don't directly manipulate the contents of mTempData in the CSS parser.  r=dbaron  a2.0=dbaron
| | |
| o |  4bb2e0074aeb - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (9/12): Add an AddLonghandProperty method to nsCSSExpandedDataBlock.  r=dbaron  a2.0=dbaron
| | |
| o |  659a0864e035 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (8/12): remove the last MoveValue call from the CSS parser.  r=dbaron  a2.0=dbaron
| | |
| o |  980f0170d982 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (7/12): cleanup pass on css/Declaration.{h,cpp} and nsCSSDataBlock.{h,cpp}.  r=dbaron  a2.0=dbaron
| | |
| o |  f09c1638d3c1 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (6/12): remove vestiges of nsCSSType.  r=dbaron  a2.0=dbaron
| | |
| o |  b88472b0af90 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (5/12): eliminate ValueList as a storage type.  r=dbaron  a2.0=dbaron
| | |
| o |  a3e21759b570 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (4/12): eliminate ValuePairList as a storage type.  r=dbaron  a2.0=dbaron
| | |
| o |  ed89c9e297ab - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (3/12): eliminate Rect as a storage type.  r=dbaron  a2.0=dbaron
| | |
| o |  4fc85e572c38 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (2/12): eliminate ValuePair as a storage type.  r=dbaron  a2.0=dbaron
| | |
| o |  301875d4f9b6 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (1/12): Move all the CSS 'storage types' (rect, value pair, etc) to nsCSSValue.h and their code to nsCSSValue.cpp.  r=dbaron  a2.0=dbaron
|/ /
o |  90ad165ae21b - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part i: Use nsIWidget::CreateChild in nsIView::CreateWidget* (where possible). r=roc a=blocking-fennecb1
| |
o |  037a5d6b376a - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part h: Add an nsIWidget::CreateChild interface to sweep (relevant to this bug) code dealing with native widgets under the widget/src/* rug. sr=roc
| |
o |  f1af117d4598 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part g: Split nsIView::CreateWidget into CreateWidget, CreateWidgetForParent, and CreateWidgetForPopup in preparation of eliminating IIDs here. sr=roc
| |
o |  5bf0b315a5aa - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part f: Split out window initialization code in preparation for multiple CreateWidget* methods. r=roc
| |
o |  353da995af6f - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part e: Simplify the logic for creating popup widgets. r=roc
| |
o |  7735c00eabe9 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part d: Simplify nsView::LoadWidget and return early if it fails. r=roc
| |
o |  7b17bcefb174 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part c: Initialize default widget init data earlier so that it's always available. r=roc
| |
o |  c5945b6a97ed - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part b: Remove nsIDeviceContext::SupportsNativeWidgets because it's not used meaningfully, and will be confusing in content processes. sr=roc
| |
o |  5452db293694 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part a: Add nsIView::Impl() and nsView::CreateWidget() to get rid of |static_cast<nsview*>(this)|. r=roc
| |
o |  9407827b5166 - Chris Jones <jones.chris.g@gmail.com> - Bug 582075, part 0.5: Add support for aInitData=NULL to the Windows nsWindow implementation. r=dougt
| |
o |  88a279b64473 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part 0: Log the repaint region bounding rect in DumpPaintEvent. r=roc
| |
o |  cebb111fbfc4 - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 3: Remove nsSVGUtils::GetThebesComputationalSurface and use gfxPlatform::ScreenReferenceSurface instead. r=jwatt
| |
o |  7b3726c3a580 - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 2: Change nsIPresShell::CreateRenderingContext to GetReferenceRenderingContext, that uses the shared 1x1 surface, and use it all over the place. r=mats,sr=dbaron
| |
o |  b3e968d831ec - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 1: Create a single static 1x1 surface in gfxPlatform that can be used to create contexts for text measurement etc. r=vlad
| |
o |  55ef0e0529bc - Mounir Lamouri <mounir.lamouri@gmail.com> - Bug 506554 - Implement the CSS3 pseudo-classes :required and :optional for HTML. r=sicking sr=bz a2.0=blocking
| |
</int></int>

We want to merge with those probably-good changesets. Note that if any of those probably-good changesets touched code you backed out, you'll need to resolve merge conflicts.

$ hg merge $MERGE_TO
92 files updated, 0 files merged, 2 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -m 'Merge backout'

OK, good to go. Your tree should look something like

@    8fccc434c295 - Chris Jones <jones.chris.g@gmail.com> - Merge backout
|\
| o  1767c1fb9418 - Chris Jones <jones.chris.g@gmail.com> - Back out bug 585817 and bug 582057
| |
o |  c6abfc89215a - Chris Pearce <chris@pearce.org.nz> - Bug 485288 - Replace all usage of video  autobuffer attribute with preload=auto. a=test-fix
| |
o |  d6e8fddeb95b - Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Disable test_preload_actions.html case 9 until bug 568402 is fixed. a=test-fix
| |
o |  571d2664ead0 - Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Don't show throbber on video controls if we're not loading a resource. r=dolske a=blocking2.0
| |
o |  3f7dfabab5e4 - Rich Dougherty <rich@rd.gen.nz>, Chris Pearce <chris@pearce.org.nz> - Bug 548523 - Replace HTMLMediaElement.autobuffer attribute with 'preload'. r=roc a=blocking2.0
| |
o |  d7d9cf4ab76a - Chris Pearce <chris@pearce.org.nz> - Bug 519897 - Supported indexed Ogg files. r=doublec
| |
o |    2a0e5811ece9 - Chris Pearce <chris@pearce.org.nz> - Commit merge of backout of 66dcf25705f9. a=backout
|\ \
| o |  958a30df30dd - Chris Pearce <chris@pearce.org.nz> - Backed out changeset 66dcf25705f9
| | |
o | |  6eead86e13dd - Michael Wu <mwu@mozilla.com> - Bug 556644 - Yet another removed-files.in update, r=rs a=blocking-beta5
| | |
o | |  69c6ce104f45 - Chris Jones <jones.chris.g@gmail.com> - Bug 588216: Avoid race between IO-thread loop->PostTask() and main-thread loop->SetNestableTasksAllowed() that led to Tasks being ignored. r=bent
| | |
o | |  73899b33ca4b - Ben Turner <bent.mozilla@gmail.com> - Bug 576716 - 'Crash [@ TypedArrayTemplate<int>::init] or [@ TypedArrayTemplate<int>::create]'. Adding a test, r=vlad a=blocker
| | |
o | |  3bd62d459019 - Mark Banner <bugzilla@standard8.plus.com> - Follow up to bug 587984 bustage fix for l10n repacks. r=Pike,ted,a=bustage-fix
| | |
o | |  e1ca9091e5a6 - Benjamin Stover <webapps@stechz.com> - Bug 575731: Make test more stable in the face of various themes. r,a=sicking
| | |
o | |  bb200e1f52b4 - Jonas Sicking <jonas@sicking.cc> - Bug 550959: Require version 2.5 of python. r=ted a=sicking
| | |
o | |  992491c618de - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (12/12): fix assertions in nsStyleAnimation triggered by part 3.  r=dbaron  a2.0=dbaron
| | |
o | |  2f078585a0f6 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (11/12): Make all assertions fatal in Declaration.h, Declaration.cpp, nsCSSDataBlock.h, nsCSSDataBlock.cpp, nsCSSValue.h, nsCSSValue.cpp, nsCSSProps.h, and nsCSSProps.cpp.  r=dbaron  a2.0=dbaron
| | |
o | |  5a9bd15fd7a8 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (10/12): Don't directly manipulate the contents of mTempData in the CSS parser.  r=dbaron  a2.0=dbaron
| | |
o | |  4bb2e0074aeb - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (9/12): Add an AddLonghandProperty method to nsCSSExpandedDataBlock.  r=dbaron  a2.0=dbaron
| | |
o | |  659a0864e035 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (8/12): remove the last MoveValue call from the CSS parser.  r=dbaron  a2.0=dbaron
| | |
o | |  980f0170d982 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (7/12): cleanup pass on css/Declaration.{h,cpp} and nsCSSDataBlock.{h,cpp}.  r=dbaron  a2.0=dbaron
| | |
o | |  f09c1638d3c1 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (6/12): remove vestiges of nsCSSType.  r=dbaron  a2.0=dbaron
| | |
o | |  b88472b0af90 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (5/12): eliminate ValueList as a storage type.  r=dbaron  a2.0=dbaron
| | |
o | |  a3e21759b570 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (4/12): eliminate ValuePairList as a storage type.  r=dbaron  a2.0=dbaron
| | |
o | |  ed89c9e297ab - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (3/12): eliminate Rect as a storage type.  r=dbaron  a2.0=dbaron
| | |
o | |  4fc85e572c38 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (2/12): eliminate ValuePair as a storage type.  r=dbaron  a2.0=dbaron
| | |
o---+  301875d4f9b6 - Zack Weinberg <zweinberg@mozilla.com> - Bug 576044 (1/12): Move all the CSS 'storage types' (rect, value pair, etc) to nsCSSValue.h and their code to nsCSSValue.cpp.  r=dbaron  a2.0=dbaron
 / /
| o  90ad165ae21b - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part i: Use nsIWidget::CreateChild in nsIView::CreateWidget* (where possible). r=roc a=blocking-fennecb1
| |
| o  037a5d6b376a - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part h: Add an nsIWidget::CreateChild interface to sweep (relevant to this bug) code dealing with native widgets under the widget/src/* rug. sr=roc
| |
| o  f1af117d4598 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part g: Split nsIView::CreateWidget into CreateWidget, CreateWidgetForParent, and CreateWidgetForPopup in preparation of eliminating IIDs here. sr=roc
| |
| o  5bf0b315a5aa - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part f: Split out window initialization code in preparation for multiple CreateWidget* methods. r=roc
| |
| o  353da995af6f - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part e: Simplify the logic for creating popup widgets. r=roc
| |
| o  7735c00eabe9 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part d: Simplify nsView::LoadWidget and return early if it fails. r=roc
| |
| o  7b17bcefb174 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part c: Initialize default widget init data earlier so that it's always available. r=roc
| |
| o  c5945b6a97ed - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part b: Remove nsIDeviceContext::SupportsNativeWidgets because it's not used meaningfully, and will be confusing in content processes. sr=roc
| |
| o  5452db293694 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part a: Add nsIView::Impl() and nsView::CreateWidget() to get rid of |static_cast<nsview*>(this)|. r=roc
| |
| o  9407827b5166 - Chris Jones <jones.chris.g@gmail.com> - Bug 582075, part 0.5: Add support for aInitData=NULL to the Windows nsWindow implementation. r=dougt
| |
| o  88a279b64473 - Chris Jones <jones.chris.g@gmail.com> - Bug 582057, part 0: Log the repaint region bounding rect in DumpPaintEvent. r=roc
| |
| o  cebb111fbfc4 - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 3: Remove nsSVGUtils::GetThebesComputationalSurface and use gfxPlatform::ScreenReferenceSurface instead. r=jwatt
| |
| o  7b3726c3a580 - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 2: Change nsIPresShell::CreateRenderingContext to GetReferenceRenderingContext, that uses the shared 1x1 surface, and use it all over the place. r=mats,sr=dbaron
| |
| o  b3e968d831ec - Robert O'Callahan <roc@ocallahan.org> - Bug 585817. Part 1: Create a single static 1x1 surface in gfxPlatform that can be used to create contexts for text measurement etc. r=vlad
| |
| o  55ef0e0529bc - Mounir Lamouri <mounir.lamouri@gmail.com> - Bug 506554 - Implement the CSS3 pseudo-classes :required and :optional for HTML. r=sicking sr=bz a2.0=blocking
| |
$ hg out
comparing with http://hg.mozilla.org/mozilla-central
searching for changes
1767c1fb9418 - Chris Jones <jones.chris.g@gmail.com> - Back out bug 585817 and bug 582057
8fccc434c295 - Chris Jones <jones.chris.g@gmail.com> - Merge backout
</int></int>

Maintaining a branch of mozilla-central

Let foo be the project you are working on. We assume that the project directory will be http://hg.mozilla.org/projects/foo and is a branch of mozilla-central. We also assume that you want to push some patches on foo and periodically synchronize both repositories.

Modify hgrc

To make things simpler, you can modify the hgrc file in the repository. You can find it here: /path/to/repository/.hg/hgrc

Change it to:

[paths]
default = http://hg.mozilla.org/projects/foo
m-c = ssh://hg.mozilla.org/mozilla-central
default-push = ssh://hg.mozilla.org/projects/foo 

You should also check in your user directory's .hgrc to make sure you don't have the bzpost extension enabled. If you merge m-c to a branch that is infrequently updated, bzpost would try to update every changed bug, creating a lot of unnecessary bugmail and noise.

Synchronize mozilla-central and foo project

You can push to foo as you would push to any repository but you might want to keep in sync both repositories. To do that, you can run these commands:

hg pull -u   # Get all the changes to foo in your repo.
hg pull m-c  # Get all the changes to mozilla-central in your repo.
hg merge     # Here, the things might be complex and would need extra carefulness.
# resolve merge conflicts, if any
hg commit -m "Merge foo with mozilla-central."
hg push      # Push the merge to foo.
hg push m-c  # Push the changes to mozilla-central.

Help

Help, I can't push!

If you're trying to push, and you can't, first try this:

$ ssh hg.mozilla.org

If you see output like:

Permission denied (publickey,gssapi-with-mic).

it may have the following reasons:

If you see output like:

You are not allowed to use this system, go away!

then you need to file a bug in mozilla.org:Server Operations.

You should expect the ssh command to disconnect you immediately, since you're not supposed to have shell access. It may give the output:

Could not chdir to home directory : No such file or directory

which is harmless (although some people see it and some people don't).

If you see output like:

ssl required

then you need to configure your default-push correctly.

Branch merges

As part of the rapid release process, the contents of e.g. mozilla-aurora and mozilla-beta are subject to merge events that happen according to the planned branch migration dates. After a branch merge event occurred, if you attempt to use "hg update" in your local tree, you may get error messages such as "abort: crosses branches". In order to fix it, first make sure you don't have local changes, then run "hg update -C -r default".

Other

What's the difference between hg pull and hg update?

hg-diagram.png

hg pull copies changesets from one repository to another.  It only brings changes into your local repository, not your working copy.  It will touch the network if you're pulling from a remote repository.

hg update updates your working copy.  It only modifies your working copy.  It will not touch the network (unless your directory is on a network filesystem).

How does Mercurial handle line endings?

The Windows version of Mercurial does not automatically convert line endings between Windows and Unix styles. All our repositories use Unix line endings. We need a story for Windows, but right now I have no ideas.

(How about a pre-commit hook that rejects pushes containing CR with a suitably informative error message? We possibly want to make exceptions for certain types of files (at least binary files of course), but we can tweak the hook as necessary as these crop up. Mercurial 1.0 adds a standard hook for this in the win32text extension that we could use/adapt. --jwatt)

See Also