Introduce new static function real_path_internal()

It accepts a new parameter, die_on_error.  If die_on_error is false,
it simply cleans up after itself and returns NULL rather than dying.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
real_path_internal(): add comment explaining use of cwd

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Introduce new function real_path_if_valid()

The function is like real_path(), except that it returns NULL on error
instead of dying.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
longest_ancestor_length(): use string_list_split()

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
longest_ancestor_length(): take a string_list argument for prefixes

Change longest_ancestor_length() to take the prefixes argument as a
string_list rather than as a colon-separated string.  This will make
it easier for the caller to alter the entries before calling
longest_ancestor_length().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
longest_ancestor_length(): require prefix list entries to be normalized

Move the responsibility for normalizing prefixes from
longest_ancestor_length() to its callers. Use slightly different
normalizations at the two callers:

In setup_git_directory_gently_1(), use the old normalization, which
ignores paths that are not usable.  In the next commit we will change
this caller to also resolve symlinks in the paths from
GIT_CEILING_DIRECTORIES as part of the normalization.

In "test-path-utils longest_ancestor_length", use the old
normalization, but die() if any paths are unusable.  Also change t0060
to only pass normalized paths to the test program (no empty entries or
non-absolute paths, strip trailing slashes from the paths, and remove
tests that thereby become redundant).

The point of this change is to reduce the scope of the ancestor_length
tests in t0060 from testing normalization+longest_prefix to testing
only mostly longest_prefix.  This is necessary because when
setup_git_directory_gently_1() starts resolving symlinks as part of
its normalization, it will not be reasonable to do the same in the
test suite, because that would make the test results depend on the
contents of the root directory of the filesystem on which the test is
run.  HOWEVER: under Windows, bash mangles arguments that look like
absolute POSIX paths into DOS paths.  So we have to retain the level
of normalization done by normalize_path_copy() to convert the
bash-mangled DOS paths (which contain backslashes) into paths that use
forward slashes.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
setup_git_directory_gently_1(): resolve symlinks in ceiling paths

longest_ancestor_length() relies on a textual comparison of directory
parts to find the part of path that overlaps with one of the paths in
prefix_list.  But this doesn't work if any of the prefixes involves a
symbolic link, because the directories will look different even though
they might logically refer to the same directory.  So canonicalize the
paths listed in GIT_CEILING_DIRECTORIES using real_path_if_valid()
before passing them to longest_ancestor_length().  (Also rename
normalize_ceiling_entry() to canonicalize_ceiling_entry() to reflect
the change.)

path is already in canonical form, so doesn't need to be canonicalized
again.

This fixes some problems with using GIT_CEILING_DIRECTORIES that
contains paths involving symlinks, including t4035 if run with --root
set to a path involving symlinks.

Please note that test t0060 is *not* changed analogously, because that
would make the test suite results dependent on the contents of the
local root directory.  However, real_path() is already tested
independently, and the "ancestor" tests cover the non-normalization
aspects of longest_ancestor_length(), so coverage remains sufficient.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
string_list_longest_prefix(): remove function

This function was added in f103f95b11d087f07c0c48bf784cd9197e18f203 in
the erroneous expectation that it would be used in the
reimplementation of longest_ancestor_length().  But it turned out to
be easier to use a function specialized for comparing path prefixes
(i.e., one that knows about slashes and root paths) than to prepare
the paths in such a way that a generic string prefix comparison
function can be used.  So delete string_list_longest_prefix() and its
documentation and test cases.

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Jeff King <peff@peff.net>
Which merge_file() function do you mean?

There are two different static functions and one global function,
all of them called "merge_file()", with different signatures and
purposes.  Rename them all to reduce confusion in "git grep" output:

 * Rename the static one in merge-index to "merge_one_path(const char
   *path)" as that function is about asking an external command to
   resolve conflicts in one path.

 * Rename the global one in merge-file.c that is only used by
   merge-tree to "merge_blobs()", as the function takes three blobs and
   returns the merged result only in-core, without doing anything to
   the filesystem.

 * Rename the one in merge-recursive to "merge_one_file()", just to be
   fair.

Also rename merge-file.[ch] to merge-blobs.[ch].

Signed-off-by: Junio C Hamano <gitster@pobox.com>
tests: move test_cmp_rev to test-lib-functions

A function for checking that two given parameters refer to the same
revision was defined in several places, so move the definition to
test-lib-functions.sh instead.

Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
learn to pick/revert into unborn branch

cherry-picking into an unborn branch should work, so make it work,
with or without --ff.

Cherry-picking anything other than a commit that only adds files, will
naturally result in conflicts. Similarly, revert also works, but will
result in conflicts unless the specified revision only deletes files.

Signed-off-by: Martin von Zweigbergk <martinvonz@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-tree: lose unused "flags" from merge_list

Drop the unused field from the structure.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-tree: lose unused "resolve_directories"

This option is always set; simplify.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-tree: add comments to clarify what these functions are doing

Rename the "branch1" parameter given to resolve() to "ours", to
clarify what is going on.  Also, annotate the unresolved_directory()
function with some comments to show what decisions are made in each
step, and highlight two bugs that need to be fixed.

Add two tests to t4300 to illustrate these bugs.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
merge-tree: fix d/f conflicts

The previous commit documented two known breakages revolving around
a case where one side flips a tree into a blob (or vice versa),
where the original code simply gets confused and feeds a mixture of
trees and blobs into either the recursive merge-tree (and recursing
into the blob will fail) or three-way merge (and merging tree contents
together with blobs will fail).

Fix it by feeding trees (and only trees) into the recursive
merge-tree machinery and blobs (and only blobs) into the three-way
content level merge machinery separately; when this happens, the
entire merge has to be marked as conflicting at the structure level.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove the suggestion to use parsecvs, which is currently broken.

The parsecvs code has been neglected for a long time, and the only
public version does not even build correctly.  I have been handed
control of the project and intend to fix this, but until I do it
cannot be recommended.

Also, the project URL given for Subversion needed to be updated
to follow their site move.

Signed-off-by: Eric S. Raymond <esr@thyrsus.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
dir.c: Make git-status --ignored more consistent

The current behavior of git-status is inconsistent and misleading.
Especially when used with --untracked-files=all option:

 - files ignored in untracked directories will be missing from
   status output.

 - untracked files in committed yet ignored directories are also
   missing.

 - with --untracked-files=normal, untracked directories that
   contains only ignored files are dropped too.

Make the behavior more consistent across all possible use cases:

 - "--ignored --untracked-files=normal" doesn't show each specific
   files but top directory.  It instead shows untracked directories
   that only contains ignored files, and ignored tracked directories
   with untracked files.

 - "--ignored --untracked-files=all" shows all ignored files, either
   because it's in an ignored directory (tracked or untracked), or
   because the file is explicitly ignored.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
git-status: Test --ignored behavior

Test all possible use-cases of git-status "--ignored" with the
"--untracked-files" option with values "normal" and "all":

 - An untracked directory is listed as untracked if it has a mix of
   untracked and ignored files in it.  With -uall, ignored/untracked
   files are listed as ignored/untracked.

 - An untracked directory with only ignored files is listed as
   ignored.  With -uall, all files in the directory are listed.

 - An ignored directory is listed as ignored. With -uall, all files
   in the directory are listed as ignored.

 - An ignored and committed directory is listed as ignored if it has
   untracked files.  With -uall, all untracked files in the
   directory are listed as ignored.

Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Documentation: update "howto maintain git"

The flow described in the document is still correct, but over time I
have automated various parts of the workflow with tools and their
use was not explained at all.

Update it and outline the use of two key scripts from the 'todo'
branch, "Reintegrate" and "cook".

Signed-off-by: Junio C Hamano <gitster@pobox.com>
howto/maintain: mark titles for asciidoc