Search for a note attached to the ref to update and read it's
'Revision-number:'-line. Start import from the next svn revision.
If there is no next revision in the svn repo, svnrdump terminates with
a message on stderr an non-zero return value. This looks a little
weird, but there is no other way to know whether there is a new
revision in the svn repo.
On the start of an incremental import, the parent of the first commit
in the fast-import stream is set to the branch name to update. All
following commits specify their parent by a mark number. Previous mark
files are currently not reused.
Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
To provide metadata from svn dumps for further processing, e.g.
branch detection, attach a note to each imported commit that stores
additional information. The notes are currently hard-coded in
refs/notes/svn/revs. Currently the following lines from the svn dump
are directly accumulated in the note. This can be refined as needed.
- "Revision-number"
- "Node-path"
- "Node-kind"
- "Node-action"
- "Node-copyfrom-path"
- "Node-copyfrom-rev"
Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The reference to update by the fast-import stream is hard-coded. When
fetching from a remote the remote-helper shall update refs in a
private namespace, i.e. a private subdir of refs/. This namespace is
defined by the 'refspec' capability, that the remote-helper advertises
as a reply to the 'capabilities' command.
Extend svndump and fast-export to allow passing the target ref.
Update svn-fe to be compatible.
Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The existing function only allows reading from a filename or from
stdin. Allow passing of a FD and an additional FD for the back report
pipe. This allows us to retrieve the name of the pipe in the caller.
Signed-off-by: Florian Achleitner <florian.achleitner.2.6.31@gmail.com>
Acked-by: David Michael Barr <b@rr-dav.id.au>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Currently the vcs-svn/ library only pays attention to the presence of
the Prop-Content-Length field and doesn't care about its value, but
some day we might care about the value. Parse it as an off_t instead
of arbitrarily limiting to 32 bits for intuitiveness.
So now you can import from a dump with more than 2 GiB of properties
for a node. In practice that isn't likely to happen often, and this
is mostly meant as a cleanup.
Based-on-patch-by: David Barr <davidbarr@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Since the length of t is already known, we can simplify a little by
using memcmp() instead of strncmp() to carry out a prefix comparison.
All nearby code already does this.
Noticed in the standalone svn-dump-fast-export project which has not
needed to implement prefixcmp() yet.
Signed-off-by: David Barr <davidbarr@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Since v1.7.5~42^2~6 (vcs-svn: remove buffer_read_string)
buffer_reset() does nothing thus fast_export_reset() also.
Signed-off-by: David Barr <davidbarr@google.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
The error handling routines add a newline. Remove
the duplicate ones in error messages.
Signed-off-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is no reason in principle that an svn-format dump would not be
able to represent a file whose length does not fit in a 32-bit
integer. Use off_t consistently to represent file lengths (in place
of using uint32_t in some contexts) so we can handle that.
Most svn-fe code is already ready to do that without this patch and
passes values of type off_t around. The type mismatch from stragglers
was noticed with gcc -Wtype-limits.
While at it, tighten the parsing of the Text-content-length field to
make sure it is a number and does not overflow, and tighten other
overflow checks as that value is passed around and manipulated.
Inspired-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There is no reason in principle that an svn-format dump would not
be able to represent a file whose length does not fit in a 32-bit
integer. Use off_t consistently (instead of uint32_t) to represent
file lengths so we can handle that.
Most of our code is already ready to do that without this patch and
already passes values of type off_t around. The type mismatch due to
stragglers was noticed with gcc -Wtype-limits.
Inspired-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
This simplifies svn-fe a great deal and fulfills a longstanding wish:
support for dumps with deltas in them, and incremental imports.
The cost is that commandline usage of the svn-fe tool becomes a little
more complicated since it no longer keeps state itself but instead reads
blobs back from fast-import in order to copy them between revisions and
apply deltas to them.
Also removes a couple of custom data structures and replaces them with
strbufs like other parts of Git.
* 'svn-fe' of git://repo.or.cz/git/jrn: (32 commits)
vcs-svn: reset first_commit_done in fast_export_init
vcs-svn: do not initialize report_buffer twice
vcs-svn: avoid hangs from corrupt deltas
vcs-svn: guard against overflow when computing preimage length
vcs-svn: cap number of bytes read from sliding view
test-svn-fe: split off "test-svn-fe -d" into a separate function
vcs-svn: implement text-delta handling
vcs-svn: let deltas use data from preimage
vcs-svn: let deltas use data from postimage
vcs-svn: verify that deltas consume all inline data
vcs-svn: implement copyfrom_data delta instruction
vcs-svn: read instructions from deltas
vcs-svn: read inline data from deltas
vcs-svn: read the preimage when applying deltas
vcs-svn: parse svndiff0 window header
vcs-svn: skeleton of an svn delta parser
vcs-svn: make buffer_read_binary API more convenient
vcs-svn: learn to maintain a sliding view of a file
Makefile: list one vcs-svn/xdiff object or header per line
vcs-svn: avoid using ls command twice
...
Conflicts:
Makefile
contrib/svn-fe/svn-fe.txt
Handle input in Subversion's dumpfile format, version 3. This is the
format produced by "svnrdump dump" and "svnadmin dump --deltas", and
the main difference between v3 dumpfiles and the dumpfiles already
handled is that these can include nodes whose properties and text are
expressed relative to some other node.
To handle such nodes, we find which node the text and properties are
based on, handle its property changes, use the cat-blob command to
request the basis blob from the fast-import backend, use the
svndiff0_apply() helper to apply the text delta on the fly, writing
output to a temporary file, and then measure that postimage file's
length and write its content to the fast-import stream.
The temporary postimage file is shared between delta-using nodes to
avoid some file system overhead.
The svn-fe interface needs to be more complicated to accomodate the
backward flow of information from the fast-import backend to svn-fe.
The backflow fd is not needed when parsing streams without deltas,
though, so existing scripts using svn-fe on v2 dumps should
continue to work.
NEEDSWORK: generalize interface so caller sets the backflow fd, close
temporary file before exiting
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
* db/svn-fe-code-purge:
vcs-svn: drop obj_pool
vcs-svn: drop treap
vcs-svn: drop string_pool
vcs-svn: pass paths through to fast-import
Conflicts:
vcs-svn/fast_export.c
vcs-svn/fast_export.h
vcs-svn/repo_tree.c
vcs-svn/repo_tree.h
vcs-svn/string_pool.c
vcs-svn/svndump.c
vcs-svn/trp.txt
This teaches svn-fe to incrementally import into an existing
repository (at last!) at the expense of less convenient UI. Think of
it as growing pains. This opens the door to many excellent things,
and it would be a bad idea to discourage people from building on it
for much longer.
* db/vcs-svn-incremental:
vcs-svn: avoid using ls command twice
vcs-svn: use mark from previous import for parent commit
vcs-svn: handle filenames with dq correctly
vcs-svn: quote paths correctly for ls command
vcs-svn: eliminate repo_tree structure
vcs-svn: add a comment before each commit
vcs-svn: save marks for imported commits
vcs-svn: use higher mark numbers for blobs
vcs-svn: set up channel to read fast-import cat-blob response
Conflicts:
t/t9010-svn-fe.sh
vcs-svn/fast_export.c
vcs-svn/fast_export.h
vcs-svn/repo_tree.c
vcs-svn/svndump.c
In particular, sparse issues the "symbol 'a_symbol' was not declared.
Should it be static?" warnings for the following symbols:
attr.c:468:12: 'git_etc_gitattributes'
attr.c:476:5: 'git_attr_system'
vcs-svn/svndump.c:282:6: 'svndump_read'
vcs-svn/svndump.c:417:5: 'svndump_init'
vcs-svn/svndump.c:432:6: 'svndump_deinit'
vcs-svn/svndump.c:445:6: 'svndump_reset'
The symbols in attr.c only require file scope, so we add the static
modifier to their declaration.
The symbols in vcs-svn/svndump.c are external symbols, and they
already have extern declarations in the "svndump.h" header file,
so we simply include the header in svndump.c.
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As v1.7.4-rc0~184 (2010-10-04) and C99 §6.8.6.4.1 remind us, standard
C does not permit returning an expression of type void, even for a
tail call.
Noticed with gcc -pedantic:
vcs-svn/svndump.c: In function 'handle_node':
vcs-svn/svndump.c:213:3: warning: ISO C forbids 'return' with expression,
in function returning void [-pedantic]
[jn: with simplified log message]
Signed-off-by: Michael Witten <mfwitten@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Currently there are two functions to retrieve the mode and content
at a path:
const char *repo_read_path(const uint32_t *path);
uint32_t repo_read_mode(const uint32_t *path)
Replace them with a single function with two return values. This
means we can use one round-trip to get the same information from
fast-import that previously took two.
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Pass the log message by strbuf instead of as a C-style string and use
fwrite instead of printf to write it to fast-import so embedded '\0'
bytes can be preserved.
Currently "git log" doesn't show the embedded NULs but "git cat-file
commit" can.
While at it, stop including system headers from repo_tree.h. git
source files need to include git-compat-util.h (or cache.h or
builtin.h) sooner to ensure the appropriate feature test macros are
defined.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Use strbuf_swap when storing the svn:log and svn:author properties, so
pointers to rather than the contents of buffers get copied. The main
effect should be to make the code a little easier to read.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
svn-fe errors out on revision 59151 of the ASF repository:
fatal: invalid dump: unexpected end of file
The proximate cause is a property with an embedded NUL character.
Previously such anomalies were ignored but commit c9d1c8ba
(2010-12-28) introduced a check strlen(val) == len to avoid reading
uninitialized data when a property list ends early and unfortunately
this test does not distinguish between "foo" followed by EOF and the
string "foo\0bar\0baz".
Fix it by using buffer_read_binary to read to a strbuf and checking
the actual length read. Most consumers of properties still use
C-style strings, so in practice an author or log message with embedded
NULs will be truncated, but a least this way svn-fe won't error out
(fixing the regression).
Reported-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Now that there is no internal representation of the repo, it is not
necessary to tokenise paths. Use strbuf instead and bypass
string_pool.
This means svn-fe can handle arbitrarily long paths (as long as a
strbuf can fit them), with arbitrarily many path components.
While at it, since we now treat paths in their entirety, only quote
when necessary.
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
* db/strbufs-for-metadata:
vcs-svn: use strbuf for author, UUID, and URL
vcs-svn: use strbuf for revision log
Conflicts:
vcs-svn/fast_export.c
vcs-svn/fast_export.h
vcs-svn/repo_tree.c
vcs-svn/svndump.c
This is a small optimisation (4% reduction in user time) but is the
largest artifact within the parsing portion of svndump.c
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Instead of interning property names and comparing their string_pool
keys, look them up in a table by string length, which should be about
as fast.
Another small step towards removing dependence on string_pool
altogether.
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Instead of interning property names and comparing their string_pool
keys, look them up in a table by string length, which should be about
as fast.
This is a small step towards removing dependence on string_pool.
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Use strbufs and strings instead of interned strings for values of rev,
dump, and node fields that happen to be strings. After this change,
the only remaining string_pool use is for paths in the repo_tree API
and internals.
Functional change: treat an empty author, UUID, or URL as none at all.
So for example, in repos where the first revision has an empty
svn:author property, the first rev will be treated as by "nobody"
rather than by a person with empty name and email address created by
prepending an @ sign to the repository UUID.
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
obj_pool is overkill for this application: all that is needed is a
buffer that can resize from rev to rev to accomodate differently-sized
strings. In the spirit of commit deadcef4 (2010-11-06), use a strbuf
instead.
This is a small step towards removing dependence on obj_pool.h.
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Catch input errors and exit early enough to print a reasonable
diagnosis based on errno.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Rely on fast-import for information about previous revs.
This requires always setting up backward flow of information, even for
v2 dumps. On the plus side, it simplifies the code by quite a bit and
opens the door to further simplifications.
[db: adjusted to support final version of the cat-blob patch]
[jn: avoiding hard-coding git's name for the empty tree for
portability to other backends]
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Current svn-fe produces output like this:
blob
mark :7382321
data 5
hello
blob
mark :7382322
data 5
Hello
commit
mark :3
[...]
M 100644 :7382321 hello.c
M 100644 :7382322 hello2.c
This means svn-fe has to keep track of the paths modified in each
commit and the corresponding marks, instead of dealing with each file
as it arrives in input and then forgetting about it. A better
strategy would be to use inline blobs:
commit
mark :3
[...]
M 100644 inline hello.c
data 5
hello
[...]
As a first step towards that, teach svn-fe to notice when the
collection of blobs for each commit starts and write a comment
("# commit 3.") there.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Set up some plumbing: teach the svndump lib to pass a file descriptor
number to the fast_export lib, representing where cat-blob/ls
responses can be read from, and add a get_response_line helper
function to the fast_export lib to read a line from that file.
Unfortunately this means that svn-fe needs file descriptor 3 to be
redirected from somewhere (preferrably the cat-blob stream of a
fast-import backend); otherwise it will fail:
$ svndump <path> | svn-fe
fatal: cannot read from file descriptor 3: Bad file descriptor
For the moment, "svn-fe 3</dev/null" works as a workaround but it
will not work for very long. A fast-import backend that can retrieve
old commits is needed in order to be able to fulfill svn
"Node-copyfrom-rev" requests that refer to revs from a previous run.
[jn: with new change description]
Based-on-patch-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Restrict the repo_tree API to functions that are actually needed.
- decouple reading the mode and content of dirents from other
operations.
- remove repo_modify_path. It is only used to read the mode from
dirents.
- remove the ability to use repo_read_mode on a missing path. The
existing code only errors out in that case, anyway.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
svn-fe processes each commit in two stages: first decide on the
correct content for all paths and export the relevant blobs, then
export a commit with the result.
But we can keep less state and simplify svn-fe a great deal by
exporting the commit in one step: use 'inline' blobs for each path and
remember nothing. This way, the repo_tree structure could be
eliminated, and we would get support for incremental imports 'for
free'.
Reorganize handle_node along these lines. This is just a code
cleanup; the changes in repo_tree and handle_revision will come later.
[db: backported to apply without text delta support]
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
* git://github.com/gitster/git:
vcs-svn: Allow change nodes for root of tree (/)
vcs-svn: Implement Prop-delta handling
vcs-svn: Sharpen parsing of property lines
vcs-svn: Split off function for handling of individual properties
vcs-svn: Make source easier to read on small screens
vcs-svn: More dump format sanity checks
vcs-svn: Reject path nodes without Node-action
vcs-svn: Delay read of per-path properties
vcs-svn: Combine repo_replace and repo_modify functions
vcs-svn: Replace = Delete + Add
vcs-svn: handle_node: Handle deletion case early
vcs-svn: Use mark to indicate nodes with included text
vcs-svn: Unclutter handle_node by introducing have_props var
vcs-svn: Eliminate node_ctx.mark global
vcs-svn: Eliminate node_ctx.srcRev global
vcs-svn: Check for errors from open()
vcs-svn: Allow simple v3 dumps (no deltas yet)
Conflicts:
t/t9010-svn-fe.sh
vcs-svn/svndump.c
Collect the line_buffer state in a newly public line_buffer struct.
Callers can use multiple line_buffers to manage input from multiple
files at a time.
svn-fe's delta applier will use this to stream a delta from svnrdump
and the preimage it applies to from fast-import at the same time.
The tests don't take advantage of the new features, but I think that's
okay. It is easier to find lingering examples of nonreentrant code by
searching for "static" in line_buffer.c.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
In particular, on systems that define uint32_t as an unsigned long,
gcc complains as follows:
CC vcs-svn/svndump.o
vcs-svn/svndump.c: In function `svndump_read':
vcs-svn/svndump.c:215: warning: int format, uint32_t arg (arg 2)
In order to suppress the warning we use the C99 format specifier
macro PRIu32 from <inttypes.h>.
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Acked-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It is not uncommon for a svn repository to include change records for
properties at the top level of the tracked tree:
Node-path:
Node-kind: dir
Node-action: change
Prop-delta: true
Prop-content-length: 43
Content-length: 43
K 10
svn:ignore
V 11
build-area
PROPS-END
Unfortunately a recent svn-fe change (vcs-svn: More dump format sanity
checks, 2010-11-19) causes such nodes to be rejected with the error
message
fatal: invalid dump: path to be modified is missing
The repo_tree module does not keep a dirent for the root of the tree.
Add a block to the dump parser to take care of this case.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The rules for what file is used as delta source for each file are not
documented in dump-load-format.txt. Luckily, the Apache Software
Foundation repository has rich enough examples to figure out most of
the rules:
Node-action: replace implies the empty property set and empty text as
preimage for deltas. Otherwise, if a copyfrom source is given, that
node is the preimage for deltas. Lastly, if none of the above applies
and the node path exists in the current revision, then that version
forms the basis.
[jn: refactored, with tests]
Signed-off-by: David Barr <david.barr@cordelta.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Prepare to add a new type of property line (the 'D' line) to
handle property deltas.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The handle_property function is the part of read_props that would be
interesting for most people: semantics of properties rather than the
algorithm for parsing them.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Remove some newlines from handle_node() that are not needed for
clarity.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Node-action: change is not appropriate when switching between file and
directory or adding a new file. Current svn-fe silently accepts such
nodes and the resulting tree has missing files in the "changed when
meant to add" case.
Node-action: add requires some content (text or directory); there is
no such thing as an "intent to add" node in svn dumps. Current svn-fe
accepts such contentless adds but produces an invalid fast-import
stream that refers to nonexistent mark :0 in response.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
It would be better to flag such errors and let the import proceed
anyway, but for now it is simpler not to worry about recovery
from such weird cases.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The mode for each file in an svn-format dump is kept in the properties
section. The properties section is read as soon as possible to allow
the correct mode to be filled in when registering the file with the
repo_tree lib.
To support nodes with a missing properties section, svn-fe determines
the mode in three stages:
- The kind (directory or file) of the node is read from the dump and
used to make an initial estimate (040000 or 100644).
- Properties are read in and allowed to override this for symlinks
and executables.
- If there is no properties section, the mode from the previous
content of the path is left alone, overriding the above
considerations.
This is a bit of a mess, and worse, it would get even more complicated
once we start to support property deltas. If we could only register
the file with a provisional value for mode and then change it later
when properties say so, the procedure would be much simpler.
... oh, right, we can.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
There are two functions to change the staged content for a path in the
svn importer's active commit: repo_replace, which changes the text and
returns the mode, and repo_modify, which changes the text and mode and
returns nothing.
Worse, there are more subtle differences:
- A mark of 0 passed to repo_modify means "use the existing content".
repo_replace uses it as mark :0 and produces a corrupt stream.
- When passed a path that is not part of the active commit,
repo_replace returns without doing anything. repo_modify
transparently adds a new directory entry.
Get rid of both and introduce a new function with the best features of
both: repo_modify_path modifies the mode, content, or both for a path,
depending on which arguments are zero. If no such dirent already
exists, it does nothing and reports the error by returning 0.
Otherwise, the return value is the resulting mode.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Simplify by reducing the "Node-action: replace" case to "Node-action:
add". This way, the main part of handle_node() only has to deal with
"add" and "change" nodes.
Functional change: replacing a symlink or executable without setting
properties will reset the mode.
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
