This patch teaches "git rev-list --bisect-vars" to output an estimate
of the number of bisection step left _after the current one_ along with
the other variables it already outputs.
This patch also makes "git-bisect.sh" display this number of steps left
_after the current one_, along with the estimate of the number of
revisions left to test (after the current one).
Here is a table to help analyse what should be the best estimate for
the number of bisect steps left.
N : linear case --> probabilities --> best
-------------------------------------------------------------
1 : G-B --> 0 --> 0
2 : G-U1-B --> 0 --> 0
3 : G-U1-U2-B --> 0(1/3) 1(2/3) --> 1
4 : G-U1-U2-U3-B --> 1 --> 1
5 : G-U1-U2-U3-U4-B --> 1(3/5) 2(2/5) --> 1
6 : G-U1-U2-U3-U4-U5-B --> 1(2/6) 2(4/6) --> 2
7 : G-U1-U2-U3-U4-U5-U6-B --> 1(1/7) 2(6/7) --> 2
8 : G-U1-U2-U3-U4-U5-U6-U7-B --> 2 --> 2
9 : G-U1-U2-U3-U4-U5-U6-U7-U8-B --> 2(7/9) 3(2/9) --> 2
10: G-U1-U2-U3-U4-U5-U6-U7-U8-U9-B --> 2(6/10)3(4/10)--> 2
In the column "N", there is the number of revisions that could _now_
be the first bad commit we are looking for.
The "linear case" column describes the linear history corresponding to
the number in column N. G means good, B means bad, and Ux means
unknown. Note that the first bad revision we are looking for can be
any Ux or B.
In the "probabilities" column, there are the different outcomes in
number of steps with the odds of each outcome in parenthesis
corresponding to the linear case.
The "best" column gives the most accurate estimate among the different
outcomes in the "probabilities" column.
We have the following:
best(2^n) == n - 1
and for any x between 0 included and 2^n excluded, the probability for
n - 1 steps left looks like:
P(2^n + x) == (2^n - x) / (2^n + x)
and P(2^n + x) < 0.5 means 2^n < 3x
So the algorithm used in this patch calculates 2^n and x, and then
choose between returning n - 1 and n.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When there is nothing to be skipped, the output from
rev-list --bisect-vars was eval'ed without first being
strung together with &&; this is probably not a problem
as it is much less likely to be a bad input than the list
handcrafted by the filter_skip function, but it still is
a good discipline.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When the "bad" commit was also "skip"ped and when more than one
commit was skipped, the "filter_skipped" function would have
printed something like:
bisect_rev=<hash1>|<hash2>
(where <hash1> and <hash2> are hexadecimal sha1 hashes)
and this would have been evaled later as piping "bisect_rev=<hash1>"
into "<hash2>", which would have failed.
So this patch makes the "filter_skipped" function properly quote
what it outputs, so that it will print something like:
bisect_rev='<hash1>|<hash2>'
which will be properly evaled later. The caller was not stopping
properly because the scriptlet this function returned to be evaled
was not strung together with && and because of this, an error in
an earlier part of the output was simply ignored.
A test case is added to the test suite.
And while at it, we also initialize the VARS, FOUND and TRIED
variables, so that we protect ourselves from environment variables
the user may have with these names.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It seems that Cygwin sets the variable SESSIONNAME when an interactive
desktop session is running, and does not set it when you log in via ssh.
So we can use this variable to determine whether to run gitk or git log
in git bisect view.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The patch that allows "git bisect skip" to be passed a range of
commits using the "<commit1>..<commit2>" notation is flawed because
it introduces a regression when it was passed a simple rev or commit.
"git bisect skip <commit>" doesn't work any more, because <commit>
is quoted but not properly unquoted.
This patch fixes that and add tests cases to better check when it is
passed commits and range of commits.
While at it, this patch also properly quotes the non range arguments
using the "sq" function.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
The current "git bisect skip" syntax is "git bisect skip [<rev>...]"
so it's already possible to skip a range of revisions using
something like:
$ git bisect skip $(git rev-list A..B)
where A and B are the bounds of the range we want to skip.
This patch teaches "git bisect skip" to accept:
$ git bisect skip A..B
as an abbreviation for the former command.
This is done by checking each argument to see if it contains two
dots one after the other ('..'), and by expending it using
"git rev-list" if that is the case.
Note that this patch will not make "git bisect skip" accept all
that "git rev-list" accepts, as things like "^A B" for exemple
will not work. But things like "A B..C D E F.. ..G H...I" should
work as expected.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Check to see given bad/good/skip sets are valid commit and to exit
otherwise was broken by 6a54d97 (bisect: remove "checkout_done" variable
used when checking merge bases, 2008-09-06).
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Using return values from the following functions:
- check_merge_bases
- check_good_are_ancestors_of_bad
seems simpler.
While at it, let's add some comments to better document the above
functions.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When one good revision is not an ancestor of the bad revision, the
merge bases between the good and the bad revision should be checked
to make sure that they are also good revisions.
A previous patch takes care of that, but it may check the merge bases
more often than really needed. In fact the previous patch did not try
to optimize this as much as possible because it is not so simple. So
this is the purpose of this patch.
One may think that when all the merge bases have been checked then
we can save a flag, so that we don't need to check the merge bases
again during the bisect process.
The problem is that the user may choose to checkout and test
something completely different from what the bisect process
suggested. In this case we have to check the merge bases again,
because there may be new merge bases relevant to the bisect
process.
That's why, in this patch, when we detect that the user tested
something else than what the bisect process suggested, we remove
the flag that says that we don't need to check the merge bases
again.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before this patch, "git bisect", when it was given some good revs that
are not ancestor of the bad rev, didn't check if the merge bases were
good. "git bisect" just supposed that the user knew what he was doing,
and that, when he said the revs were good, he knew that it meant that
all the revs in the history leading to the good revs were also
considered good.
But in pratice, the user may not know that a good rev is not an
ancestor of the bad rev, or he may not know/remember that all revs
leading to the good rev will be considered good. So he may give a good
rev that is a sibling, instead of an ancestor, of the bad rev, when in
fact there can be one rev becoming good in the branch of the good rev
(because the bug was already fixed there, for example) instead of one
rev becoming bad in the branch of the bad rev.
For example, if there is the following history:
A--B--C--D
\
E--F
and we launch "git bisect start D F" then only C and D would have been
considered as possible first bad commit before this patch. This could
invite user errors; F could be the commit that fixes the bug that exists
everywhere else.
The purpose of this patch is to detect when "git bisect" is passed
some good revs that are not ancestors of the bad rev, and then to first
ask the user to test the merge bases between the good and bad revs.
If the merge bases are good then all is fine, we can continue
bisecting. Otherwise, if one merge base is bad, it means that the
assumption that all revs leading to the good one are good too is
wrong and we error out. In the case where one merge base is skipped we
issue a warning and then continue bisecting anyway.
These checks will also catch the case where good and bad have been
mistaken. This means that we can remove the check that was done latter
on the output of "git rev-list --bisect-vars".
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Given that users are supposed to type 'git bisect' now, make the output
of 'git bisect log' consistent with this.
Signed-off-by: Miklos Vajna <vmiklos@frugalware.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It seems simpler and safer to use the BISECT_START file everywhere
to decide if we are bisecting or not, instead of using it in some
places and BISECT_NAMES in other places.
In commit 6459c7c678 (Nov 18 2007,
Bisect: use "$GIT_DIR/BISECT_NAMES" to check if we are bisecting.),
we decided to use BISECT_NAMES but code changed a lot and we now
have to check BISECT_START first in the "bisect_start" function
anyway.
This patch also makes things a little bit safer by creating
the BISECT_START file first and deleting it last, and also by
adding checks in "bisect_clean_state".
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When "git bisect" was first written, it was not possible to
checkout a detached HEAD. The detached feature appeared latter.
That's why before this patch the "git bisect" process used a
"bisect" branch to checkout new revisions to be tested (and also
a "new-bisect" one to check if the checkouts could work).
This patch makes "git bisect" checkout revisions to be tested on
a detached HEAD. This simplifies the code a bit.
The tests to check that "git bisect" does not start if a
"bisect" or a "new-bisect" branch exists are removed as they
are not relevant any more.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before this patch, when using "git bisect start" with mistaken revs
or when the checkout of the branch we want to test failed, we exited
after having written files like ".git/BISECT_START",
".git/BISECT_NAMES" and after having written "refs/bisect/bad" and
"refs/bisect/good-*" refs.
With this patch we trap all errors that can happen when writing the
new state and when we are in "bisect_next". So that we can try to
clean up everything in case of problems, using "bisect_clean_state".
This patch also contains a "bisect_write" cleanup to make it exit
on error and return 0 otherwise.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before this patch, when using for example:
$ git bisect start <stuff1> <stuff2>
with <stuff1> or <stuff2> that cannot be parsed as a revision, we
could leave a ".git/BISECT_START" file, from a previous
"git bisect start", alone.
This patch makes sure that it does not happen by removing the
"BISECT_START" file in "bisect_clean_state" and then always writing
it again at the end of "bisect_start".
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before this patch no error was printed when "git rev-list --bisect-vars"
failed. This can happen when bad and good revs are mistaken.
This patch prints an error message on stderr that describe the likely
failure cause.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If a branch named "bisect" or "new-bisect" already was created in the
repo by other means than git bisect, doing a git bisect used to override
the branch without a warning. Now if the branch "bisect" or
"new-bisect" already exists, and it was not created by git bisect itself,
git bisect start fails with an appropriate error message. Additionally,
if checking out a new bisect state fails due to a merge problem, git
bisect cleans up the temporary branch "new-bisect".
The accidental override has been noticed by Andres Salomon, reported
through
http://bugs.debian.org/478647
Signed-off-by: Gerrit Pape <pape@smarden.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before this patch, when "git bisect start", "git bisect good" or
"git bisect skip" were called with many revisions, they could fail
after having already marked some revisions as "good", "bad" or
"skip".
This could be especilally bad for "git bisect start" because as
the file ".git/BISECT_NAMES" would not have been written, there
would have been no attempt to clear the marked revisions on a
"git bisect reset". That's because if there is no
".git/BISECT_NAMES" file, nothing is done to clean things up, as
the bisect session is not supposed to have started.
While at it, let's also create the ".git/BISECT_START" file, only
after ".git/BISECT_NAMES" as been created.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To get the current HEAD when we start bisecting using for example
"git bisect start", we first try "git symbolic-ref HEAD" to get a
nice name, and if it fails, we fall back to "git rev-parse
--verify HEAD".
The problem is that when "git symbolic-ref HEAD" fails, it
displays "fatal: ref HEAD not a symref", so it looks like "git
bisect start" failed and does not accept detached HEAD, even if
in fact it worked fine.
This patch adds "-q" option to the "git symbolic-ref" call to
get rid of the misleading error message.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The previous one overwrote the variable used to report the bad input
when the input is actually bad, and we did not give a useful enough
information. This corrects it.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It seems that "git bisect good" and "git bisect skip" have never
properly checked arguments that have been passed to them. As soon
as one of them can be parsed as a SHA1, no error or warning would
be given.
This is because 'git rev-parse --revs-only --no-flags "$@"' always
"exit 0" and outputs all the SHA1 it can found from parsing "$@".
This patch fix this by using, for each "bisect good" argument, the
same logic as for the "bisect bad" argument.
While at it, this patch teaches "bisect bad" to give a meaningfull
error message when it is passed more than one argument.
Note that if "git bisect good" or "git bisect skip" is given some
proper revs and then something that is not a proper rev, then the
first proper revs will still have been marked as "good" or "skip".
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Users are not often aware of the fact that "git bisect -h" can give
them a long usage description, as "git bisect" seems to accept only
dashless subcommands like "start", "good", ...
That's why this patch adds a "git bisect help" subcommand that just
calls "git bisect -h". This new subcommand is also fully documented
in the short usage string (that "git bisect" gives), in the long
usage string and in the man page (that "git help bisect" gives).
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Specifying character ranges in tr differs between System V
and POSIX. In System V, brackets are required (e.g.,
'[A-Z]'), whereas in POSIX they are not.
We can mostly get around this by just using the bracket form
for both sets, as in:
tr '[A-Z] '[a-z]'
in which case POSIX interpets this as "'[' becomes '['",
which is OK.
However, this doesn't work with multiple sequences, like:
# rot13
tr '[A-Z][a-z]' '[N-Z][A-M][n-z][a-m]'
where the POSIX version does not behave the same as the
System V version. In this case, we must simply enumerate the
sequence.
This patch fixes problematic uses of tr in git scripts and
test scripts in one of three ways:
- if a single sequence, make sure it uses brackets
- if multiple sequences, enumerate
- if extra brackets (e.g., tr '[A]' 'a'), eliminate
brackets
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This error message is very confusing---it doesn't tell the user
anything about how to fix the situation. And the actual fix
for the situation ("git bisect reset") does a checkout of a
potentially random branch, (compared to what the user wants to
be on for the bisect she is starting).
The simplest way to eliminate the confusion is to just make
"git bisect start" do the cleanup itself. There's no significant
loss of safety here since we already have a general safety in
the form of the reflog.
Note: We preserve the warning for any cogito users. We do this
by switching from .git/head-name to .git/BISECT_START for the
extra state, (which is a more descriptive name anyway).
Signed-off-by: Carl Worth <cworth@cworth.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This error message is very confusing---it doesn't tell the user
anything about how to fix the situation. And the actual fix
for the situation ("git bisect reset") does a checkout of a
potentially random branch, (compared to what the user wants to
be on for the bisect she is starting).
The simplest way to eliminate the confusion is to just make
"git bisect start" do the cleanup itself. There's no significant
loss of safety here since we already have a general safety in
the form of the reflog.
Note: We preserve the warning for any cogito users. We do this
by switching from .git/head-name to .git/BISECT_START for the
extra state, (which is a more descriptive name anyway).
Signed-off-by: Carl Worth <cworth@cworth.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When deciding if gitk or git-log should be used to visualize the current
state, the environment variable DISPLAY was checked. Now, we check
MSYSTEM (for MinGW32/MSys) and SECURITYSESSIONID (for MacOSX) in addition.
Note that there is currently no way to ssh into MinGW32, and that
SECURITYSESSIONID is not set automatically on MacOSX when ssh'ing into it.
So this patch should be safe.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Due to a typo, the commit subject was shell expanded in the bisect log.
That is, if you had some shell pattern in the commit subject, bisect
would happily put all matching file names into the log.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Instead of insisting on a symbolic ref, bisect now accepts detached
HEADs, too.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This teaches "git bisect visualize" to be more useful in non-windowed
environments.
(1) When no option is given, and $DISPLAY is set, it continues to
spawn gitk as before;
(2) When no option is given, and $DISPLAY is unset, "git log" is run
to show the range of commits between the bad one and the good ones;
(3) If only "-flag" options are given, "git log <options>" is run.
E.g. "git bisect visualize --stat"
(4) Otherwise, all of the given options are taken as the initial part
of the command line and the commit range expression is given to
that command. E.g. "git bisect visualize tig" will run "tig"
history viewer to show between the bad one and the good ones.
As "visualize" is a bit too long to type, we also give it a shorter
synonym "view".
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Before this patch, using "git bisect reset" when not bisecting
did a "git checkout master" for no good reason.
This also happened using "git bisect replay" when not bisecting
because "bisect_replay" starts by calling "bisect_reset".
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Previously we tested if the "$GIT_DIR/refs/bisect" directory
existed, to check if we were bisecting.
Now with packed refs, it is simpler to check if the file
"$GIT_DIR/BISECT_NAMES" exists, as it is already created when
starting bisection and removed when reseting bisection.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In bisect_visualize, "cd $GIT_DIR/refs && echo bisect/good-*" was
still used instead of "git for-each-ref". This patch fix it.
We now pass "refs/bisect/bad" and "--not refs/bisect/good-<rev>"
instead of "bisect/bad" and "--not bisect/good-<rev>" to gitk,
but it seems to work.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When switching to a new rev, we first made "new-bisect" branch to
point at the chosen commit, attempt to switch to it, and then
finally renamed the new-bisect branch to bisect by hand when
successful. This is so that we can catch checkout failure (your
local modification may interfere with switching to the chosen
version) without losing information on which commit the next
attempt should be made.
Rewrite it using a more modern form but without breaking the
safety.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This removes the last instance of making a ref by hand with
"echo SHA1 >.git/refs/$refname" from the script and replaces it
with update-ref.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We do not need to pipe "echo" to "sed" only to strip refs/heads/
from the beginning. We are assuming not-so-ancient shells these
days.
Also there is no need to avoid assuming \012 is the LF; we do
not run on EBCDIC, sorry. Other parts of the script already
uses tr to convert separator to LF that way.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If refs were ever packed in the middle of bisection, the bisect
refs were not removed from the "packed-refs" file.
This patch fixes this problem by using "git update-ref -d $ref $hash"
in "bisect_clean_state".
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
\n is not portable in a s/// replacement string, only
in the regex part. backslash-newline helps.
Signed-off-by: Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
--text follows this line--
These commands currently lack OPTIONS_SPEC; allow people to
easily list with "git grep 'OPTIONS_SPEC=$'" what they can help
improving.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is incompatible with previous versions because an exit code
of 125 used to mark current commit as "bad". But hopefully this exit
code is not much used by test scripts or other programs. (126 and 127
are used by POSIX compliant shells to mean "found but not
executable" and "command not found", respectively.)
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Also use "die" instead of "echo >&2 something ; exit 1".
And simplify "bisect_replay".
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When there are some "skip"ped revisions, we add the '--bisect-all'
option to "git rev-list --bisect-vars". Then we filter out the
"skip"ped revisions from the result of the rev-list command, and we
modify the "bisect_rev" var accordingly.
We don't always use "--bisect-all" because it is slower
than "--bisect-vars" or "--bisect".
When we cannot find for sure the first bad commit because of
"skip"ped commits, we print the hash of each possible first bad
commit and then we exit with code 2.
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
This allows you to say:
git bisect start
git bisect bad $bad
git bisect next
to start bisection without knowing a good commit. This would
have you try a commit that is half-way since the beginning of
the history, which is rather wasteful if you already know a good
commit, but if you don't (or your history is short enough that
you do not care), there is no reason not to allow this.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Christian Couder