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Monday, December 31, 2012

Git 1.8.1

The latest release has just been tagged. Thanks, everybody, and a happy new year.






Git v1.8.1 Release Notes
========================

Backward compatibility notes
----------------------------

In the next major release (not *this* one), we will change the
behavior of the "git push" command.

When "git push [$there]" does not say what to push, we have used the
traditional "matching" semantics so far (all your branches were sent
to the remote as long as there already are branches of the same name
over there).  We will use the "simple" semantics that pushes the
current branch to the branch with the same name, only when the current
branch is set to integrate with that remote branch.  There is a user
preference configuration variable "push.default" to change this, and
"git push" will warn about the upcoming change until you set this
variable in this release.

"git branch --set-upstream" is deprecated and may be removed in a
relatively distant future.  "git branch [-u|--set-upstream-to]" has
been introduced with a saner order of arguments to replace it.


Updates since v1.8.0
--------------------

UI, Workflows & Features

 * Command-line completion scripts for tcsh and zsh have been added.

 * "git-prompt" scriptlet (in contrib/completion) can be told to paint
   pieces of the hints in the prompt string in colors.

 * Some documentation pages that used to ship only in the plain text
   format are now formatted in HTML as well.

 * We used to have a workaround for a bug in ancient "less" that
   causes it to exit without any output when the terminal is resized.
   The bug has been fixed in "less" version 406 (June 2007), and the
   workaround has been removed in this release.

 * When "git checkout" checks out a branch, it tells the user how far
   behind (or ahead) the new branch is relative to the remote tracking
   branch it builds upon.  The message now also advises how to sync
   them up by pushing or pulling.  This can be disabled with the
   advice.statusHints configuration variable.

 * "git config --get" used to diagnose presence of multiple
   definitions of the same variable in the same configuration file as
   an error, but it now applies the "last one wins" rule used by the
   internal configuration logic.  Strictly speaking, this may be an
   API regression but it is expected that nobody will notice it in
   practice.

 * A new configuration variable "diff.context" can be used to
   give the default number of context lines in the patch output, to
   override the hardcoded default of 3 lines.

 * "git format-patch" learned the "--notes=" option to give
   notes for the commit after the three-dash lines in its output.

 * "git log -p -S" now looks for the  after applying
   the textconv filter (if defined); earlier it inspected the contents
   of the blobs without filtering.

 * "git log --grep=" learned to honor the "grep.patterntype"
   configuration set to "perl".

 * "git replace -d " now interprets  as an extended
   SHA-1 (e.g. HEAD~4 is allowed), instead of only accepting full hex
   object name.

 * "git rm $submodule" used to punt on removing a submodule working
   tree to avoid losing the repository embedded in it.  Because
   recent git uses a mechanism to separate the submodule repository
   from the submodule working tree, "git rm" learned to detect this
   case and removes the submodule working tree when it is safe to do so.

 * "git send-email" used to prompt for the sender address, even when
   the committer identity is well specified (e.g. via user.name and
   user.email configuration variables).  The command no longer gives
   this prompt when not necessary.

 * "git send-email" did not allow non-address garbage strings to
   appear after addresses on Cc: lines in the patch files (and when
   told to pick them up to find more recipients), e.g.

     Cc: Stable Kernel  # for v3.2 and up

   The command now strips " # for v3.2 and up" part before adding the
   remainder of this line to the list of recipients.

 * "git submodule add" learned to add a new submodule at the same
   path as the path where an unrelated submodule was bound to in an
   existing revision via the "--name" option.

 * "git submodule sync" learned the "--recursive" option.

 * "diff.submodule" configuration variable can be used to give custom
   default value to the "git diff --submodule" option.

 * "git symbolic-ref" learned the "-d $symref" option to delete the
   named symbolic ref, which is more intuitive way to spell it than
   "update-ref -d --no-deref $symref".


Foreign Interface

 * "git cvsimport" can be told to record timezones (other than GMT)
   per-author via its author info file.

 * The remote helper interface to interact with subversion
   repositories (one of the GSoC 2012 projects) has been merged.

 * A new remote-helper interface for Mercurial has been added to
   contrib/remote-helpers.

 * The documentation for git(1) was pointing at a page at an external
   site for the list of authors that no longer existed.  The link has
   been updated to point at an alternative site.


Performance, Internal Implementation, etc.

 * Compilation on Cygwin with newer header files are supported now.

 * A couple of low-level implementation updates on MinGW.

 * The logic to generate the initial advertisement from "upload-pack"
   (i.e. what is invoked by "git fetch" on the other side of the
   connection) to list what refs are available in the repository has
   been optimized.

 * The logic to find set of attributes that match a given path has
   been optimized.

 * Use preloadindex in "git diff-index" and "git update-index", which
   has a nice speedup on systems with slow stat calls (and even on
   Linux).


Also contains minor documentation updates and code clean-ups.


Fixes since v1.8.0
------------------

Unless otherwise noted, all the fixes since v1.8.0 in the maintenance
track are contained in this release (see release notes to them for
details).

 * The configuration parser had an unnecessary hardcoded limit on
   variable names that was not checked consistently.

 * The "say" function in the test scaffolding incorrectly allowed
   "echo" to interpret "\a" as if it were a C-string asking for a
   BEL output.

 * "git mergetool" feeds /dev/null as a common ancestor when dealing
   with an add/add conflict, but p4merge backend cannot handle
   it. Work it around by passing a temporary empty file.

 * "git log -F -E --grep=''" failed to use the given 
   pattern as extended regular expression, and instead looked for the
   string literally.

 * "git grep -e pattern " asked the attribute system to read
   ":.gitattributes" file in the working tree, which was
   nonsense.

 * A symbolic ref refs/heads/SYM was not correctly removed with "git
   branch -d SYM"; the command removed the ref pointed by SYM
   instead.

 * Update "remote tracking branch" in the documentation to
   "remote-tracking branch".

 * "git pull --rebase" run while the HEAD is detached tried to find
   the upstream branch of the detached HEAD (which by definition
   does not exist) and emitted unnecessary error messages.

 * The refs/replace hierarchy was not mentioned in the
   repository-layout docs.

 * Various rfc2047 quoting issues around a non-ASCII name on the
   From: line in the output from format-patch have been corrected.

 * Sometimes curl_multi_timeout() function suggested a wrong timeout
   value when there is no file descriptor to wait on and the http
   transport ended up sleeping for minutes in select(2) system call.
   A workaround has been added for this.

 * For a fetch refspec (or the result of applying wildcard on one),
   we always want the RHS to map to something inside "refs/"
   hierarchy, but the logic to check it was not exactly right.
   (merge 5c08c1f jc/maint-fetch-tighten-refname-check later to maint).

 * "git diff -G" did not honor textconv filter when looking
   for changes.

 * Some HTTP servers ask for auth only during the actual packing phase
   (not in ls-remote phase); this is not really a recommended
   configuration, but the clients used to fail to authenticate with
   such servers.
   (merge 2e736fd jk/maint-http-half-auth-fetch later to maint).

 * "git p4" used to try expanding malformed "$keyword$" that spans
   across multiple lines.

 * Syntax highlighting in "gitweb" was not quite working.

 * RSS feed from "gitweb" had a xss hole in its title output.

 * "git config --path $key" segfaulted on "[section] key" (a boolean
   "true" spelled without "=", not "[section] key = true").

 * "git checkout -b foo" while on an unborn branch did not say
   "Switched to a new branch 'foo'" like other cases.

 * Various codepaths have workaround for a common misconfiguration to
   spell "UTF-8" as "utf8", but it was not used uniformly.  Most
   notably, mailinfo (which is used by "git am") lacked this support.

 * We failed to mention a file without any content change but whose
   permission bit was modified, or (worse yet) a new file without any
   content in the "git diff --stat" output.

 * When "--stat-count" hides a diffstat for binary contents, the total
   number of added and removed lines at the bottom was computed
   incorrectly.

 * When "--stat-count" hides a diffstat for unmerged paths, the total
   number of affected files at the bottom of the "diff --stat" output
   was computed incorrectly.

 * "diff --shortstat" miscounted the total number of affected files
   when there were unmerged paths.

 * "update-ref -d --deref SYM" to delete a ref through a symbolic ref
   that points to it did not remove it correctly.

Sunday, December 30, 2012

Is there any science in Amazon pricing?

I keep a handful of stuff in the "Saved for later" category in my Amazon shopping cart. It is amusing to see that prices of some items constantly keep changing.

Take these earbuds, for example. I listen to podcasts while commuting with a pair of earbuds plugged to my phone, and for that purpose audiophile-grade fidelity is not a requirement. Ones from different brands I tried over time, including these, have developed frayed wire just outside the connector plug and died after several months' use. Cheap earbuds are consumables to me, and I keep a couple of unopened spares around, and restock every once in a while.

They used to be around $20, but among several colors, I noticed that one particular color started selling below $10 a few weeks ago. A few days ago it was at $8.26 and then this morning I saw it at $8.06. Another example I saw was that a deck of cards that lists at $45 fluctuated both upwards and downwards between around $30 to $45 within just a few weeks. I saw a similar pattern between $140-$160 for a pair of men's shoes within three weeks.

I am guessing one of the reasons why they keep changing the prices is because they want to encourage customers to come back to their shopping cart often. I however wonder how the price fluctuations are computed. Is it random-walk just to make sure that "The prices of items in your cart changed" notice appears often enough, or is there a deep science based on supply-and-demand and consumer psychology involved? Perhaps they are measuring how low they have to go before I move an item out of the "Saved for later" bin to see how bad a cheapskate I am?

I can understand why the price of this DVD that I kept in the "Saved for later" for the last three years gradually climbed before December 25th and then dropped soon after that day every year. But I do not expect there is much seasonality in demand with earbuds or deck of cards.

Saturday, December 22, 2012

Git 1.8.1-rc3

I was hoping that we can do the real 1.8.1 release this weekend, and have a slow week or two towards the new year, but I ended up with an extra release candidate. Hopefully this will be the last rc release before the real thing.

A good news is that this delay was not caused by any last minute show-stopper regression. Rather, it was only to improve the quality of the pre-formatted documentation pages that are produced when the release is made. Relative to the previous 1.8.1-rc2, the only changes in the source tarball are documentation updates.

I've updated the AsciiDoc toolchain that is used to produce the pre-formatted documentation pages (git-htmldocs and git-manpages) to a newer version. I was assuming that the distributions all build their own versions of documentation pages with their versions of tools, but apparently some of them cheat and package these pre-formatted pages and give them to their customers. So if you are a developers of such a distribution, you may want to double-check the documentation tarballs for this release candidate.

The final will be tagged sometime around the end of the year or early next year.

Monday, December 10, 2012

Git 1.8.0.2

While we advance toward the v1.8.1 release on the 'master' front, fixes to a few bugs have been merged to the maintenance track and v1.8.0.2 has been tagged.


The release tarballs are found at:

    http://code.google.com/p/git-core/downloads/list

and their SHA-1 checksums are:

1e1640794596da40f35194c29a8cc4e41c6b4f6d  git-1.8.0.2.tar.gz
6b9e14c5b19b2e27605014252febd61a700012a3  git-htmldocs-1.8.0.2.tar.gz
ce0673256ce90451269a82a2464eab060adbfec6  git-manpages-1.8.0.2.tar.gz

Please upgrade.



Fixes since v1.8.0.1

  • Various codepaths have workaround for a common misconfiguration to spell "UTF-8" as "utf8", but it was not used uniformly.  Most notably, mailinfo (which is used by "git am") lacked this support.
  • We failed to mention a file without any content change but whose permission bit was modified, or (worse yet) a new file without any content in the "git diff --stat" output.
  • When "--stat-count" hides a diffstat for binary contents, the total   number of added and removed lines at the bottom was computed incorrectly.
  • When "--stat-count" hides a diffstat for unmerged paths, the total   number of affected files at the bottom of the "diff --stat" output was computed incorrectly.
  • "diff --shortstat" miscounted the total number of affected files when there were unmerged paths.
  • "git p4" used to try expanding malformed "$keyword$" that spans across multiple lines.
  • "git update-ref -d --deref SYM" to delete a ref through a symbolic ref that points to it did not remove it correctly.
  • Syntax highlighting in "gitweb" was not quite working.


Also contains other minor fixes and documentation updates.