clear parsed flag when we free tree buffers

Many code paths will free a tree object's buffer and set it
to NULL after finishing with it in order to keep memory
usage down during a traversal. However, out of 8 sites that
do this, only one actually unsets the "parsed" flag back.
Those sites that don't are setting a trap for later users of
the tree object; even after calling parse_tree, the buffer
will remain NULL, causing potential segfaults.

It is not known whether this is triggerable in the current
code. Most commands do not do an in-memory traversal
followed by actually using the objects again. However, it
does not hurt to be safe for future callers.

In most cases, we can abstract this out to a
"free_tree_buffer" helper. However, there are two
exceptions:

  1. The fsck code relies on the parsed flag to know that we
     were able to parse the object at one point. We can
     switch this to using a flag in the "flags" field.

  2. The index-pack code sets the buffer to NULL but does
     not free it (it is freed by a caller). We should still
     unset the parsed flag here, but we cannot use our
     helper, as we do not want to free the buffer.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
setup_reflog_action: document the rules for using GIT_REFLOG_ACTION

The set_reflog_action helper (in git-sh-setup) is designed to be
used once at the very top of a program, like this in "git am", for
example:

	set_reflog_action am

The helper function sets the given string to GIT_REFLOG_ACTION only
when GIT_REFLOG_ACTION is not yet set.  Thanks to this, "git am",
when run as the top-level program, will use "am" in GIT_REFLOG_ACTION
and the reflog entries made by whatever it does will record the
updates of refs done by "am".

Because of the conditional assignment, when "git am" is run as a
subprogram (i.e. an implementation detail) of "git rebase" that
already sets GIT_REFLOG_ACTION to its own name, the call in "git am"
to the helper function at the beginning will *not* have any effect.

So "git rebase" can do this:

	set_reflog_action rebase
	... do its own preparation, like checking out "onto" commit
        ... decide to do "format-patch" to "am" pipeline
        	git format-patch --stdout >mbox
		git am mbox

and the reflog entries made inside "git am" invocation will say
"rebase", not "am".

Calls to "git" commands that update refs would use GIT_REFLOG_ACTION
to record who did that update.  Most such calls in scripted Porcelains
do not define custom reflog message and rely on GIT_REFLOG_ACTION to
contain its (or its caller's, when it is called as a subprogram) name.

If a scripted Porcelain wants to record a custom reflog message for
a single invocation of "git" command (e.g. when "git rebase" uses
"git checkout" to detach HEAD at the commit a series is to be
replayed on), it needs to set GIT_REFLOG_ACTION to the custom
message and export it while calling the "git" command, but such an
assignment must be restricted to that single "git" invocation and
should not be left behind to affect later codepath.

Document the rules to avoid future confusion.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
t9300: document fast-import empty path issues

When given an empty path, fast-import sometimes reports "missing"
instead of using the root tree object.  On top of this, for "ls" and
file copy (but not move) it dies with "Empty path component found in
input".

Document this behaviour with failing test cases.

Reported-by: Dave Abrahams <dave@boostpro.com>
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fast-import: set valid mode on root tree in "ls"

This prevents a failure later when we lift the restriction on ls with
the empty path.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fast-import: allow ls or filecopy of the root tree

Commit 178e1de (fast-import: don't allow 'ls' of path with empty
components, 2012-03-09) restricted paths which:

    . contain an empty directory component (e.g. foo//bar is invalid),
    . end with a directory separator (e.g. foo/ is invalid),
    . start with a directory separator (e.g. /foo is invalid).

However, the implementation also caught the empty path, which should
represent the root tree.  Relax this restriction so that the empty path
is explicitly allowed and refers to the root tree.

Reported-by: Dave Abrahams <dave@boostpro.com>
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
fast-import: allow moving the root tree

Because fast-import.c::tree_content_remove does not check for the empty
path, it is not possible to move the root tree to a subdirectory.
Instead the error "Path  not in branch" is produced (note the double
space where the empty path has been inserted).

Fix this by explicitly checking for the empty path and handling it.

Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Git.pm: add new temp_is_locked function

The temp_is_locked function can be used to determine whether
or not a given name previously passed to temp_acquire is
currently locked.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-svn: allow git-svn fetching to work using serf

When attempting to git-svn fetch files from an svn https?: url using
the serf library (the only choice starting with svn 1.8) the following
errors can occur:

Temp file with moniker 'svn_delta' already in use at Git.pm line 1250
Temp file with moniker 'git_blob' already in use at Git.pm line 1250

David Rothenberger <daveroth@acm.org> has determined the cause to
be that ra_serf does not drive the delta editor in a depth-first
manner [...]. Instead, the calls come in this order:

1. open_root
2. open_directory
3. add_file
4. apply_textdelta
5. add_file
6. apply_textdelta

When using the ra_serf access method, git-svn can end up needing
to create several temp files before the first one is closed.

This change causes a new temp file moniker to be generated if the
one that would otherwise have been used is currently locked.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
cache.h: move remote/connect API out of it

The definition of "struct ref" in "cache.h", a header file so
central to the system, always confused me.  This structure is not
about the local ref used by sha1-name API to name local objects.

It is what refspecs are expanded into, after finding out what refs
the other side has, to define what refs are updated after object
transfer succeeds to what values.  It belongs to "remote.h" together
with "struct refspec".

While we are at it, also move the types and functions related to the
Git transport connection to a new header file connect.h

Signed-off-by: Junio C Hamano <gitster@pobox.com>
builtin/push.c: use OPT_BOOL, not OPT_BOOLEAN

The command line parser of "git push" for "--tags", "--delete", and
"--thin" options still used outdated OPT_BOOLEAN.  Because these
options do not give escalating levels when given multiple times,
they should use OPT_BOOL.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
check-ignore: the name of the character is NUL, not NULL

Signed-off-by: Junio C Hamano <gitster@pobox.com>
check-attr: the name of the character is NUL, not NULL

Signed-off-by: Junio C Hamano <gitster@pobox.com>
check-ignore -z: a single -z should apply to both input and output

Unless a command has separate --nul-terminated-{input,output}
options, the --nul-terminated-records (-z) option should apply
to both input and output for consistency.  The caller knows that its
input paths may need to be protected for LF, and the program shows
these problematic paths to its output.

The code already did the right thing.  Only the help text needs
fixing.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
check-attr -z: a single -z should apply to both input and output

Unless a command has separate --nul-terminated-{input,output}
options, the --nul-terminated-records (-z) option should apply
to both input and output for consistency.  The caller knows that its
input paths may need to be protected for LF, and the program shows
these problematic paths to its output.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
clean: remove unused variable "seen"

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
move struct pathspec and related functions to pathspec.[ch]

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
pathspec: i18n-ize error strings in pathspec parsing code

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
pathspec: add copy_pathspec

Because free_pathspec wants to free "items" pointer in the pathspec
structure, a simple structure assignment is not enough if you want to
copy an existing pathspec into another.  Freeing the original will
damage the copy unless a deep copy is made.

Note that the strings in pathspec->items->match and the array
pathspec->raw[] are still shared between the original and the copy.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
add parse_pathspec() that converts cmdline args to struct pathspec

Currently to fill a struct pathspec, we do:

   const char **paths;
   paths = get_pathspec(prefix, argv);
   ...
   init_pathspec(&pathspec, paths);

"paths" can only carry bare strings, which loses information from
command line arguments such as pathspec magic or the prefix part's
length for each argument.

parse_pathspec() is introduced to combine the two calls into one. The
plan is gradually replace all get_pathspec() and init_pathspec() with
parse_pathspec(). get_pathspec() now becomes a thin wrapper of
parse_pathspec().

parse_pathspec() allows the caller to reject the pathspec magics that
it does not support. When a new pathspec magic is introduced, we can
enable it per command after making sure that all underlying code has no
problem with the new magic.

"flags" parameter is currently unused. But it would allow callers to
pass certain instructions to parse_pathspec, for example forcing
literal pathspec when no magic is used.

With the introduction of parse_pathspec, there are now two functions
that can initialize struct pathspec: init_pathspec and
parse_pathspec. Any semantic changes in struct pathspec must be
reflected in both functions. init_pathspec() will be phased out in
favor of parse_pathspec().

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
parse_pathspec: save original pathspec for reporting

We usually use pathspec_item's match field for pathspec error
reporting. However "match" (or "raw") does not show the magic part,
which will play more important role later on. Preserve exact user
input for reporting.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>