Documentation/RelNotes/2.1.0.txt - jrn/git - Git at Google

 Git v2.1 Release Notes
 ======================

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

  * The default value we give to the environment variable LESS has been
    changed from "FRSX" to "FRX", losing "S" (chop long lines instead
    of wrapping).  Existing users who prefer not to see line-wrapped
    output may want to set

      $ git config core.pager "less -S"

    to restore the traditional behaviour.  It is expected that people
    find output from the most subcommands easier to read with the new
    default, except for "blame" which tends to produce really long
    lines.  To override the new default only for "git blame", you can
    do this:

      $ git config pager.blame "less -S"

  * A few disused directories in contrib/ have been retired.


 Updates since v2.0
 ------------------

 UI, Workflows & Features

  * Since the very beginning of Git, we gave the LESS environment a
    default value "FRSX" when we spawn "less" as the pager.  "S" (chop
    long lines instead of wrapping) has been removed from this default
    set of options, because it is more or less a personal taste thing,
    as opposed to others that have good justifications (i.e. "R" is
    very much justified because many kinds of output we produce are
    colored and "FX" is justified because output we produce is often
    shorter than a page).

  * The logic and data used to compute the display width needed for
    UTF-8 strings have been updated to match Unicode 7.0 better.

  * HTTP-based transports learned to propagate the error messages from
    the webserver better to the client coming over the HTTP transport.

  * The completion script for bash (in contrib/) has been updated to
    handle aliases that define complex sequence of commands better.

  * The "core.preloadindex" configuration variable is by default
    enabled, allowing modern platforms to take advantage of the
    multiple cores they have.

  * "git commit --date=<date>" option learned to read from more
    timestamp formats, including "--date=now".

  * The `core.commentChar` configuration variable is used to specify a
    custom comment character other than the default "#" to be used in
    the commit log editor.  This can be set to `auto` to attempt to
    choose a different character that does not conflict with what
    already starts a line in the message being edited for cases like
    "git commit --amend".

  * "git format-patch" learned --signature-file=<file> to take the mail
    signature from.

  * "git grep" learned grep.fullname configuration variable to force
    "--full-name" to be default.  This may cause regressions on
    scripted users that do not expect this new behaviour.

  * "git imap-send" learned to ask the credential helper for auth
    material.

  * "git log" and friends now understand the value "auto" set to the
    "log.decorate" configuration variable to enable the "--decorate"
    option automatically when the output is sent to tty.

  * "git merge" without argument, even when there is an upstream
    defined for the current branch, refused to run until
    merge.defaultToUpstream is set to true.  Flip the default of that
    configuration variable to true.

  * "git mergetool" learned to drive the vimdiff3 backend.

  * mergetool.prompt used to default to 'true', always asking "do you
    really want to run the tool on this path?".  Among the two
    purposes this prompt serves, ignore the use case to confirm that
    the user wants to view particular path with the named tool, and
    redefine the meaning of the prompt only to confirm the choice of
    the tool made by the autodetection (for those who configured the
    tool explicitly, the prompt shown for the latter purpose is
    simply annoying).

    Strictly speaking, this is a backward incompatible change and the
    users need to explicitly set the variable to 'true' if they want
    to resurrect the now-ignored use case.

  * "git replace" learned the "--edit" subcommand.

  * "git send-email" learned "--to-cover" and "--cc-cover" options, to
    tell it to copy To: and Cc: headers found in the first input file
    when emitting later input files.

  * "git svn" learned to cope with malformed timestamps with only one
    digit in the hour part, e.g. 2014-01-07T5:01:02.048176Z, emitted
    by some broken subversion server implementations.

  * "git tag" when editing the tag message shows the name of the tag
    being edited as a comment in the editor.


 Performance, Internal Implementation, etc.

  * Build procedure for 'subtree' (in contrib/) has been cleaned up.

  * The `core.deltabasecachelimit` used to default to 16 MiB , but this
    proved to be too small, and has been bumped to 96 MiB.

  * "git blame" has been optimized greatly by reorganising the data
    structure that is used to keep track of the work to be done.

  * "git diff" that compares 3-or-more trees (e.g. parents and the
    result of a merge) have been optimized.

  * The API to update/delete references are being converted to handle
    updates to multiple references in a transactional way.  As an
    example, "update-ref --stdin [-z]" has been updated to use this
    API.

  * Parts of the test scripts can be skipped by using a range notation,
    e.g. "sh t1234-test.sh --run='1-4 6 8-'" to omit test piece 5 and 7
    and run everything else.


 Also contains various documentation updates and code clean-ups.


 Fixes since v2.0
 ----------------

 Unless otherwise noted, all the fixes since v2.0 in the maintenance
 track are contained in this release (see the maintenance releases'
 notes for details).

  * We used to unconditionally disable the pager in the pager process
    we spawn to feed out output, but that prevented people who want to
    run "less" within "less" from doing so.
    (merge c0459ca je/pager-do-not-recurse later to maint).

  * Tools that read diagnostic output in our standard error stream do
    not want to see terminal control sequence (e.g. erase-to-eol).
    Detect them by checking if the standard error stream is connected
    to a tty.
    (merge 38de156 mn/sideband-no-ansi later to maint).

  * Mishandling of patterns in .gitignore that has trailing SPs quoted
    with backslashes (e.g. ones that end with "\ ") have been
    corrected.
    (merge 97c1364be6b pb/trim-trailing-spaces later to maint).

  * Reworded the error message given upon a failure to open an existing
    loose object file due to e.g. permission issues; it was reported as
    the object being corrupt, but that is not quite true.
    (merge d6c8a05 jk/report-fail-to-read-objects-better later to maint).

  * "git log -2master" is a common typo that shows two commits starting
    from whichever random branch that is not 'master' that happens to
    be checked out currently.
    (merge e3fa568 jc/revision-dash-count-parsing later to maint).

  * The "%<(10,trunc)%s" pretty format specifier in the log family of
    commands is used to truncate the string to a given length (e.g. 10
    in the example) with padding to column-align the output, but did
    not take into account that number of bytes and number of display
    columns are different.
    (merge 7d50987 as/pretty-truncate later to maint).

  * The "mailmap.file" configuration option did not support the tilde
    expansion (i.e. ~user/path and ~/path).
    (merge 9352fd5 ow/config-mailmap-pathname later to maint).

  * The completion scripts (in contrib/) did not know about quite a few
    options that are common between "git merge" and "git pull", and a
    couple of options unique to "git merge".
    (merge 8fee872 jk/complete-merge-pull later to maint).

  * "--ignore-space-change" option of "git apply" ignored the spaces
    at the beginning of line too aggressively, which is inconsistent
    with the option of the same name "diff" and "git diff" have.
    (merge 14d3bb4 jc/apply-ignore-whitespace later to maint).

  * "git blame" miscounted number of columns needed to show localized
    timestamps, resulting in jaggy left-side-edge of the source code
    lines in its output.
    (merge dd75553 jx/blame-align-relative-time later to maint).

  * "git blame" assigned the blame to the copy in the working-tree if
    the repository is set to core.autocrlf=input and the file used CRLF
    line endings.
    (merge 4d4813a bc/blame-crlf-test later to maint).

  * "git commit --allow-empty-messag -C $commit" did not work when the
    commit did not have any log message.
    (merge 076cbd6 jk/commit-C-pick-empty later to maint).

  * "git diff --find-copies-harder" sometimes pretended as if the mode
    bits have changed for paths that are marked with assume-unchanged
    bit.
    (merge 5304810 jk/diff-files-assume-unchanged later to maint).

  * "git format-patch" did not enforce the rule that the "--follow"
    option from the log/diff family of commands must be used with
    exactly one pathspec.
    (merge dd63f16 jk/diff-follow-must-take-one-pathspec later to maint).

  * "git gc --auto" was recently changed to run in the background to
    give control back early to the end-user sitting in front of the
    terminal, but it forgot that housekeeping involving reflogs should
    be done without other processes competing for accesses to the refs.
    (merge 62aad18 nd/daemonize-gc later to maint).

  * "git grep -O" to show the lines that hit in the pager did not work
    well with case insensitive search.  We now spawn "less" with its
    "-I" option when it is used as the pager (which is the default).
    (merge f7febbe sk/spawn-less-case-insensitively-from-grep-O-i later to maint).

  * We used to disable threaded "git index-pack" on platforms without
    thread-safe pread(); use a different workaround for such
    platforms to allow threaded "git index-pack".
    (merge 3953949 nd/index-pack-one-fd-per-thread later to maint).

  * The error reporting from "git index-pack" has been improved to
    distinguish missing objects from type errors.
    (merge 77583e7 jk/index-pack-report-missing later to maint).

  * "git mailinfo" used to read beyond the end of header string while
    parsing an incoming e-mail message to extract the patch.
    (merge b1a013d rs/mailinfo-header-cmp later to maint).

  * On a case insensitive filesystem, merge-recursive incorrectly
    deleted the file that is to be renamed to a name that is the same
    except for case differences.
    (merge baa37bf dt/merge-recursive-case-insensitive later to maint).

  * "git pack-objects" unnecessarily copied the previous contents when
    extending the hashtable, even though it will populate the table
    from scratch anyway.
    (merge fb79947 rs/pack-objects-no-unnecessary-realloc later to maint).

  * Recent updates to "git repack" started to duplicate objects that
    are in packfiles marked with .keep flag into the new packfile by
    mistake.
    (merge d078d85 jk/repack-pack-keep-objects later to maint).

  * "git rerere forget" did not work well when merge.conflictstyle
    was set to a non-default value.
    (merge de3d8bb fc/rerere-conflict-style later to maint).

  * "git remote rm" and "git remote prune" can involve removing many
    refs at once, which is not a very efficient thing to do when very
    many refs exist in the packed-refs file.
    (merge e6bea66 jl/remote-rm-prune later to maint).

  * "git log --exclude=<glob> --all | git shortlog" worked as expected,
    but "git shortlog --exclude=<glob> --all", which is supposed to be
    identical to the above pipeline, was not accepted at the command
    line argument parser level.
    (merge eb07774 jc/shortlog-ref-exclude later to maint).

  * The autostash mode of "git rebase -i" did not restore the dirty
    working tree state if the user aborted the interactive rebase by
    emptying the insn sheet.
    (merge ddb5432 rr/rebase-autostash-fix later to maint).

  * "git show -s" (i.e. show log message only) used to incorrectly emit
    an extra blank line after a merge commit.
    (merge ad2f725 mk/show-s-no-extra-blank-line-for-merges later to maint).

  * "git status", even though it is a read-only operation, tries to
    update the index with refreshed lstat(2) info to optimize future
    accesses to the working tree opportunistically, but this could
    race with a "read-write" operation that modify the index while it
    is running.  Detect such a race and avoid overwriting the index.
    (merge 426ddee ym/fix-opportunistic-index-update-race later to maint).

  * "git status" (and "git commit") behaved as if changes in a modified
    submodule are not there if submodule.*.ignore configuration is set,
    which was misleading.  The configuration is only to unclutter diff
    output during the course of development, and should not to hide
    changes in the "status" output to cause the users forget to commit
    them.
    (merge c215d3d jl/status-added-submodule-is-never-ignored later to maint).

  * Documentation for "git submodule sync" forgot to say that the subcommand
    can take the "--recursive" option.
    (merge 9393ae7 mc/doc-submodule-sync-recurse later to maint).

  * "git update-index --cacheinfo" in 2.0 release crashed on a
    malformed command line.
    (merge c8e1ee4 jc/rev-parse-argh-dashed-multi-words later to maint).

  * The mode to run tests with HTTP server tests disabled was broken.
    (merge afa53fe na/no-http-test-in-the-middle later to maint).
	Git v2.1 Release Notes
	======================

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

	* The default value we give to the environment variable LESS has been
	changed from "FRSX" to "FRX", losing "S" (chop long lines instead
	of wrapping). Existing users who prefer not to see line-wrapped
	output may want to set

	$ git config core.pager "less -S"

	to restore the traditional behaviour. It is expected that people
	find output from the most subcommands easier to read with the new
	default, except for "blame" which tends to produce really long
	lines. To override the new default only for "git blame", you can
	do this:

	$ git config pager.blame "less -S"

	* A few disused directories in contrib/ have been retired.


	Updates since v2.0
	------------------

	UI, Workflows & Features

	* Since the very beginning of Git, we gave the LESS environment a
	default value "FRSX" when we spawn "less" as the pager. "S" (chop
	long lines instead of wrapping) has been removed from this default
	set of options, because it is more or less a personal taste thing,
	as opposed to others that have good justifications (i.e. "R" is
	very much justified because many kinds of output we produce are
	colored and "FX" is justified because output we produce is often
	shorter than a page).

	* The logic and data used to compute the display width needed for
	UTF-8 strings have been updated to match Unicode 7.0 better.

	* HTTP-based transports learned to propagate the error messages from
	the webserver better to the client coming over the HTTP transport.

	* The completion script for bash (in contrib/) has been updated to
	handle aliases that define complex sequence of commands better.

	* The "core.preloadindex" configuration variable is by default
	enabled, allowing modern platforms to take advantage of the
	multiple cores they have.

	* "git commit --date=<date>" option learned to read from more
	timestamp formats, including "--date=now".

	* The `core.commentChar` configuration variable is used to specify a
	custom comment character other than the default "#" to be used in
	the commit log editor. This can be set to `auto` to attempt to
	choose a different character that does not conflict with what
	already starts a line in the message being edited for cases like
	"git commit --amend".

	* "git format-patch" learned --signature-file=<file> to take the mail
	signature from.

	* "git grep" learned grep.fullname configuration variable to force
	"--full-name" to be default. This may cause regressions on
	scripted users that do not expect this new behaviour.

	* "git imap-send" learned to ask the credential helper for auth
	material.

	* "git log" and friends now understand the value "auto" set to the
	"log.decorate" configuration variable to enable the "--decorate"
	option automatically when the output is sent to tty.

	* "git merge" without argument, even when there is an upstream
	defined for the current branch, refused to run until
	merge.defaultToUpstream is set to true. Flip the default of that
	configuration variable to true.

	* "git mergetool" learned to drive the vimdiff3 backend.

	* mergetool.prompt used to default to 'true', always asking "do you
	really want to run the tool on this path?". Among the two
	purposes this prompt serves, ignore the use case to confirm that
	the user wants to view particular path with the named tool, and
	redefine the meaning of the prompt only to confirm the choice of
	the tool made by the autodetection (for those who configured the
	tool explicitly, the prompt shown for the latter purpose is
	simply annoying).

	Strictly speaking, this is a backward incompatible change and the
	users need to explicitly set the variable to 'true' if they want
	to resurrect the now-ignored use case.

	* "git replace" learned the "--edit" subcommand.

	* "git send-email" learned "--to-cover" and "--cc-cover" options, to
	tell it to copy To: and Cc: headers found in the first input file
	when emitting later input files.

	* "git svn" learned to cope with malformed timestamps with only one
	digit in the hour part, e.g. 2014-01-07T5:01:02.048176Z, emitted
	by some broken subversion server implementations.

	* "git tag" when editing the tag message shows the name of the tag
	being edited as a comment in the editor.


	Performance, Internal Implementation, etc.

	* Build procedure for 'subtree' (in contrib/) has been cleaned up.

	* The `core.deltabasecachelimit` used to default to 16 MiB , but this
	proved to be too small, and has been bumped to 96 MiB.

	* "git blame" has been optimized greatly by reorganising the data
	structure that is used to keep track of the work to be done.

	* "git diff" that compares 3-or-more trees (e.g. parents and the
	result of a merge) have been optimized.

	* The API to update/delete references are being converted to handle
	updates to multiple references in a transactional way. As an
	example, "update-ref --stdin [-z]" has been updated to use this
	API.

	* Parts of the test scripts can be skipped by using a range notation,
	e.g. "sh t1234-test.sh --run='1-4 6 8-'" to omit test piece 5 and 7
	and run everything else.


	Also contains various documentation updates and code clean-ups.


	Fixes since v2.0
	----------------

	Unless otherwise noted, all the fixes since v2.0 in the maintenance
	track are contained in this release (see the maintenance releases'
	notes for details).

	* We used to unconditionally disable the pager in the pager process
	we spawn to feed out output, but that prevented people who want to
	run "less" within "less" from doing so.
	(merge c0459ca je/pager-do-not-recurse later to maint).

	* Tools that read diagnostic output in our standard error stream do
	not want to see terminal control sequence (e.g. erase-to-eol).
	Detect them by checking if the standard error stream is connected
	to a tty.
	(merge 38de156 mn/sideband-no-ansi later to maint).

	* Mishandling of patterns in .gitignore that has trailing SPs quoted
	with backslashes (e.g. ones that end with "\ ") have been
	corrected.
	(merge 97c1364be6b pb/trim-trailing-spaces later to maint).

	* Reworded the error message given upon a failure to open an existing
	loose object file due to e.g. permission issues; it was reported as
	the object being corrupt, but that is not quite true.
	(merge d6c8a05 jk/report-fail-to-read-objects-better later to maint).

	* "git log -2master" is a common typo that shows two commits starting
	from whichever random branch that is not 'master' that happens to
	be checked out currently.
	(merge e3fa568 jc/revision-dash-count-parsing later to maint).

	* The "%<(10,trunc)%s" pretty format specifier in the log family of
	commands is used to truncate the string to a given length (e.g. 10
	in the example) with padding to column-align the output, but did
	not take into account that number of bytes and number of display
	columns are different.
	(merge 7d50987 as/pretty-truncate later to maint).

	* The "mailmap.file" configuration option did not support the tilde
	expansion (i.e. ~user/path and ~/path).
	(merge 9352fd5 ow/config-mailmap-pathname later to maint).

	* The completion scripts (in contrib/) did not know about quite a few
	options that are common between "git merge" and "git pull", and a
	couple of options unique to "git merge".
	(merge 8fee872 jk/complete-merge-pull later to maint).

	* "--ignore-space-change" option of "git apply" ignored the spaces
	at the beginning of line too aggressively, which is inconsistent
	with the option of the same name "diff" and "git diff" have.
	(merge 14d3bb4 jc/apply-ignore-whitespace later to maint).

	* "git blame" miscounted number of columns needed to show localized
	timestamps, resulting in jaggy left-side-edge of the source code
	lines in its output.
	(merge dd75553 jx/blame-align-relative-time later to maint).

	* "git blame" assigned the blame to the copy in the working-tree if
	the repository is set to core.autocrlf=input and the file used CRLF
	line endings.
	(merge 4d4813a bc/blame-crlf-test later to maint).

	* "git commit --allow-empty-messag -C $commit" did not work when the
	commit did not have any log message.
	(merge 076cbd6 jk/commit-C-pick-empty later to maint).

	* "git diff --find-copies-harder" sometimes pretended as if the mode
	bits have changed for paths that are marked with assume-unchanged
	bit.
	(merge 5304810 jk/diff-files-assume-unchanged later to maint).

	* "git format-patch" did not enforce the rule that the "--follow"
	option from the log/diff family of commands must be used with
	exactly one pathspec.
	(merge dd63f16 jk/diff-follow-must-take-one-pathspec later to maint).

	* "git gc --auto" was recently changed to run in the background to
	give control back early to the end-user sitting in front of the
	terminal, but it forgot that housekeeping involving reflogs should
	be done without other processes competing for accesses to the refs.
	(merge 62aad18 nd/daemonize-gc later to maint).

	* "git grep -O" to show the lines that hit in the pager did not work
	well with case insensitive search. We now spawn "less" with its
	"-I" option when it is used as the pager (which is the default).
	(merge f7febbe sk/spawn-less-case-insensitively-from-grep-O-i later to maint).

	* We used to disable threaded "git index-pack" on platforms without
	thread-safe pread(); use a different workaround for such
	platforms to allow threaded "git index-pack".
	(merge 3953949 nd/index-pack-one-fd-per-thread later to maint).

	* The error reporting from "git index-pack" has been improved to
	distinguish missing objects from type errors.
	(merge 77583e7 jk/index-pack-report-missing later to maint).

	* "git mailinfo" used to read beyond the end of header string while
	parsing an incoming e-mail message to extract the patch.
	(merge b1a013d rs/mailinfo-header-cmp later to maint).

	* On a case insensitive filesystem, merge-recursive incorrectly
	deleted the file that is to be renamed to a name that is the same
	except for case differences.
	(merge baa37bf dt/merge-recursive-case-insensitive later to maint).

	* "git pack-objects" unnecessarily copied the previous contents when
	extending the hashtable, even though it will populate the table
	from scratch anyway.
	(merge fb79947 rs/pack-objects-no-unnecessary-realloc later to maint).

	* Recent updates to "git repack" started to duplicate objects that
	are in packfiles marked with .keep flag into the new packfile by
	mistake.
	(merge d078d85 jk/repack-pack-keep-objects later to maint).

	* "git rerere forget" did not work well when merge.conflictstyle
	was set to a non-default value.
	(merge de3d8bb fc/rerere-conflict-style later to maint).

	* "git remote rm" and "git remote prune" can involve removing many
	refs at once, which is not a very efficient thing to do when very
	many refs exist in the packed-refs file.
	(merge e6bea66 jl/remote-rm-prune later to maint).

	* "git log --exclude=<glob> --all \| git shortlog" worked as expected,
	but "git shortlog --exclude=<glob> --all", which is supposed to be
	identical to the above pipeline, was not accepted at the command
	line argument parser level.
	(merge eb07774 jc/shortlog-ref-exclude later to maint).

	* The autostash mode of "git rebase -i" did not restore the dirty
	working tree state if the user aborted the interactive rebase by
	emptying the insn sheet.
	(merge ddb5432 rr/rebase-autostash-fix later to maint).

	* "git show -s" (i.e. show log message only) used to incorrectly emit
	an extra blank line after a merge commit.
	(merge ad2f725 mk/show-s-no-extra-blank-line-for-merges later to maint).

	* "git status", even though it is a read-only operation, tries to
	update the index with refreshed lstat(2) info to optimize future
	accesses to the working tree opportunistically, but this could
	race with a "read-write" operation that modify the index while it
	is running. Detect such a race and avoid overwriting the index.
	(merge 426ddee ym/fix-opportunistic-index-update-race later to maint).

	* "git status" (and "git commit") behaved as if changes in a modified
	submodule are not there if submodule.*.ignore configuration is set,
	which was misleading. The configuration is only to unclutter diff
	output during the course of development, and should not to hide
	changes in the "status" output to cause the users forget to commit
	them.
	(merge c215d3d jl/status-added-submodule-is-never-ignored later to maint).

	* Documentation for "git submodule sync" forgot to say that the subcommand
	can take the "--recursive" option.
	(merge 9393ae7 mc/doc-submodule-sync-recurse later to maint).

	* "git update-index --cacheinfo" in 2.0 release crashed on a
	malformed command line.
	(merge c8e1ee4 jc/rev-parse-argh-dashed-multi-words later to maint).

	* The mode to run tests with HTTP server tests disabled was broken.
	(merge afa53fe na/no-http-test-in-the-middle later to maint).