perl: redirect stderr to /dev/null instead of closing

On my system, t9100.1 triggers the following warning:

  ==352== Syscall param write(buf) points to uninitialised byte(s)
  ==352==    at 0x57119C0: __write_nocancel (in /lib64/libc-2.17.so)
  ==352==    by 0x56AC1D2: _IO_file_write@@GLIBC_2.2.5 (in /lib64/libc-2.17.so)
  ==352==    by 0x56AC0B1: new_do_write (in /lib64/libc-2.17.so)
  ==352==    by 0x56AD3B4: _IO_do_write@@GLIBC_2.2.5 (in /lib64/libc-2.17.so)
  ==352==    by 0x56AD6FE: _IO_file_overflow@@GLIBC_2.2.5 (in /lib64/libc-2.17.so)
  ==352==    by 0x56AE3D8: _IO_default_xsputn (in /lib64/libc-2.17.so)
  ==352==    by 0x56ACAA2: _IO_file_xsputn@@GLIBC_2.2.5 (in /lib64/libc-2.17.so)
  ==352==    by 0x5682133: buffered_vfprintf (in /lib64/libc-2.17.so)
  ==352==    by 0x567CE9D: vfprintf (in /lib64/libc-2.17.so)
  ==352==    by 0x5687096: fprintf (in /lib64/libc-2.17.so)
  ==352==    by 0x4E7AC5: vreportf (usage.c:15)
  ==352==    by 0x4E7B14: die_builtin (usage.c:38)

The actual complaint appears to be a bug in the underlying
implementation.  What's interesting here is that it is apparently
_triggered_ by closing stderr, which results in (from strace)

  write(2, "fatal: Needed a single revision\n", 32) = -1 EBADF (Bad file descriptor)
  write(2, "\0", 1) = -1 EBADF (Bad file descriptor)

Closing stderr is a bad idea anyway: there is a very real chance that
we print fatal error messages to some other file that just happens to
be opened on the now-free FD 2.  So let's not do that.

As pointed out by Eric Wong (thanks), the initial close needs to go:
die() would again write nowhere if we close STDERR beforehand.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Signed-off-by: Eric Wong <normalperson@yhbt.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
t9700: do not close STDERR

Much like the previous patch, this triggered an unrelated bug.
Closing STDERR is not worth it anyway, as we risk writing die() and
such to random files that happen to be subsequently opened on FD 2.
Don't do it.

Signed-off-by: Thomas Rast <trast@inf.ethz.ch>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-merge(1): document diff-algorithm option to merge-recursive

Commit 07924d4 (diff: Introduce --diff-algorithm command line option
2013-01-16) added diff-algorithm as a parameter to the recursive merge
strategy but did not document it.  Do so.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff: allow unstuck arguments with --diff-algorithm

The argument to --diff-algorithm is mandatory, so there is no reason to
require the argument to be stuck to the option with '='.  Change this
for consistency with other Git commands.

Note that this does not change the handling of diff-algorithm in
merge-recursive.c since the primary interface to that is via the -X
option to 'git merge' where the unstuck form does not make sense.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
submodule: print graph output next to submodule log

When running "git log -p --submodule=log", the submodule log is not
indented by the graph output, although all other lines are.  Fix this by
prepending the current line prefix to each line of the submodule log.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
http: add HTTP_KEEP_ERROR option

We currently set curl's FAILONERROR option, which means that
any http failures are reported as curl errors, and the
http body content from the server is thrown away.

This patch introduces a new option to http_get_strbuf which
specifies that the body content from a failed http response
should be placed in the destination strbuf, where it can be
accessed by the caller.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-curl: show server content on http errors

If an http request to a remote git server fails, we show
only the http response code, or sometimes a custom message
for particular codes. This gives the server no opportunity
to offer a more detailed explanation of the reason for the
failure, or to give extra advice.

This patch teaches remote-curl to record and display the
body content of a failed http response. We only display such
responses when the content-type is advertised as text/plain,
as it is the most likely to look presentable on the user's
terminal (and it is hoped to be a good indication that the
message is intended for git clients, and not for a web
browser).

Each line of the new output is prepended with "remote:".
Example output may look like this (assuming the server is
configured to display such a helpful message):

  $ GIT_SMART_HTTP=0 git clone https://example.com/some/repo.git
  Cloning into 'repo'...
  remote: Sorry, fetching via dumb http is forbidden.
  remote: Please upgrade your git client to v1.6.6 or greater
  remote: and make sure that smart-http is enabled.
  error: The requested URL returned error: 403 while accessing http://localhost:5001/some/repo.git/info/refs
  fatal: HTTP request failed

For the sake of simplicity, we only record and display these
errors during the initial fetch of the ref list, as that is
the initial contact with the server and where the most
common, interesting errors happen (and there is already
precedent, as that is the only place we currently massage
http error codes into more helpful messages).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-curl: let servers override http 404 advice

When we get an http 404 trying to get the initial list of
refs from the server, we try to be helpful and remind the
user that update-server-info may need to be run. This looks
like:

  $ git clone https://github.com/non/existent
  Cloning into 'existent'...
  fatal: https://github.com/non/existent/info/refs?service=git-upload-pack not found: did you run git update-server-info on the server?

Suggesting update-server-info may be a good suggestion for
users who are in control of the server repo and who are
planning to set up dumb http. But for users of smart http,
and especially users who are not in control of the server
repo, the advice is useless and confusing.

The previous patch taught remote-curl to show custom advice
from the server when it is available. When we have shown
messages from the server, we can also drop our custom
advice; what the server has to say is likely to be more
accurate and helpful.

We not only drop the mention of update-server-info, but also
show only the main repo URL, not the full "info/refs" and
service parameter. These elements may be useful for
debugging a broken server configuration, but again, anything
the server has provided is likely to be more useful (and one
can still use GIT_CURL_VERBOSE to get much more complete
debugging information).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-curl: always show friendlier 404 message

When we get an http 404 trying to get the initial list of
refs from the server, we try to be helpful and remind the
user that update-server-info may need to be run. This looks
like:

  $ git clone https://github.com/non/existent
  Cloning into 'existent'...
  fatal: https://github.com/non/existent/info/refs?service=git-upload-pack not found: did you run git update-server-info on the server?

Suggesting update-server-info may be a good suggestion for
users who are in control of the server repo and who are
planning to set up dumb http. But for users of smart http,
and especially users who are not in control of the server
repo, the advice is useless and confusing.

Since most people are expected to use smart http these days,
it does not make sense to keep the update-server-info hint.

We not only drop the mention of update-server-info, but also
show only the main repo URL, not the full "info/refs" and
service parameter. These elements may be useful for
debugging a broken server configuration, but in the majority
of cases, users are not fetching from their own
repositories, but rather from other people's repositories;
they have neither the power nor interest to fix a broken
configuration, and the extra components just make the
message more confusing. Users who do want to debug can and
should use GIT_CURL_VERBOSE to get more complete information
on the actual URLs visited.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-curl: consistently report repo url for http errors

When we report http errors in fetching the initial ref
advertisement, we show the full URL we attempted to use,
including "info/refs?service=git-upload-pack". While this
may be useful for debugging a broken server, it is
unnecessarily verbose and confusing for most cases, in which
the client user is not even the same person as the owner of
the repository.

Let's just show the repository URL; debugging can happen
with GIT_CURL_VERBOSE, which shows way more useful
information, anyway.

At the same time, let's also make sure to mention the
repository URL when we report failed authentication
(previously we said only "Authentication failed"). Knowing
the URL can help the user realize why authentication failed
(e.g., they meant to push to remote A, not remote B).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
http: simplify http_error helper function

This helper function should really be a one-liner that
prints an error message, but it has ended up unnecessarily
complicated:

  1. We call error() directly when we fail to start the curl
     request, so we must later avoid printing a duplicate
     error in http_error().

     It would be much simpler in this case to just stuff the
     error message into our usual curl_errorstr buffer
     rather than printing it ourselves. This means that
     http_error does not even have to care about curl's exit
     value (the interesting part is in the errorstr buffer
     already).

  2. We return the "ret" value passed in to us, but none of
     the callers actually cares about our return value. We
     can just drop this entirely.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
http: re-word http error message

When we report an http error code, we say something like:

  error: The requested URL reported failure: 403 Forbidden while accessing http://example.com/repo.git

Everything between "error:" and "while" is written by curl,
and the resulting sentence is hard to read (especially
because there is no punctuation between curl's sentence and
the remainder of ours). Instead, let's re-order this to give
better flow:

  error: unable to access 'http://example.com/repo.git: The requested URL reported failure: 403 Forbidden

This is still annoyingly long, but at least reads more
clearly left to right.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
remote-curl: die directly with http error messages

When we encounter an unknown http error (e.g., a 403), we
hand the error code to http_error, which then prints it with
error(). After that we die with the redundant message "HTTP
request failed".

Instead, let's just drop http_error entirely, which does
nothing but pass arguments to error(), and instead die
directly with a useful message.

So before:

  $ git clone https://example.com/repo.git
  Cloning into 'repo'...
  error: unable to access 'https://example.com/repo.git': The requested URL returned error: 403 Forbidden
  fatal: HTTP request failed

and after:

  $ git clone https://example.com/repo.git
  Cloning into 'repo'...
  fatal: unable to access 'https://example.com/repo.git': The requested URL returned error: 403 Forbidden

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
http: drop http_error function

This function is a single-liner and is only called from one
place. Just inline it, which makes the code more obvious.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
show-branch: use strbuf instead of static buffer

When we generate relative names (e.g., "master~20^2"), we
format the name into a static buffer, then xstrdup the
result to attach it to the commit. Since the first thing we
add into the static buffer is the already-computed name of
the child commit, the names may get longer and longer as
the traversal gets deeper, and we may eventually overflow
the fixed-size buffer.

Fix this by converting the fixed-size buffer into a dynamic
strbuf.  The performance implications should be minimal, as
we end up allocating a heap copy of the name anyway (and now
we can just detach the heap copy from the strbuf).

Reported-by: Eric Roman <eroman@chromium.org>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fmt-merge-msg: respect core.commentchar in people credits

Commit eff80a9 (Allow custom "comment char") introduced a custom
comment character for commit messages but forgot to use it in
people credits which can be a part of a commit message.

With this commit, the custom comment character is also used
in people credits.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fmt-merge-msg: use core.commentchar in tag signatures completely

Commit eff80a9 (Allow custom "comment char") introduced a custom
comment character for commit messages but didn't use it completely
in the tag signature part.

This commit fixes that.

Signed-off-by: Ralf Thielow <ralf.thielow@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
bundle: Accept prerequisites without commit messages

While explicitly stating that the commit message in a prerequisite
line is optional, we required all lines with 40 or more characters
to contain a space after the object name, bailing out if a line
consisted of an object name only. This was to allow bundling a
history to a commit without an message, but the code forgot that it
already called rtrim() to remove that whitespace.

As a workaround, only check for SP when the line has more than 40
characters.

Signed-off-by: Lukas Fleischer <git@cryptocrack.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'tr/perl-keep-stderr-open'

Closing (not redirecting to /dev/null) the standard error stream is
not a very smart thing to do.  Later open may return file
descriptor #2 for unrelated purpose, and error reporting code may
write into them.

* tr/perl-keep-stderr-open:
  t9700: do not close STDERR
  perl: redirect stderr to /dev/null instead of closing
Merge branch 'jk/http-error-messages'

Improve error reporting from the http transfer clients.

* jk/http-error-messages:
  http: drop http_error function
  remote-curl: die directly with http error messages
  http: re-word http error message
  http: simplify http_error helper function
  remote-curl: consistently report repo url for http errors
  remote-curl: always show friendlier 404 message
  remote-curl: let servers override http 404 advice
  remote-curl: show server content on http errors
  http: add HTTP_KEEP_ERROR option