git-merge-tree causes a null pointer dereference when a directory
entry exists in only one or two of the three trees being compared with
no corresponding entry in the other tree(s).
When this happens, we want to handle the entry as a directory and not
attempt to mark it as a file merge. Do this by setting the entries bit
in the directory mask when the entry is missing or when it is a
directory, only performing the file comparison when we know that a file
entry exists.
Reported-by: Andreas Jacobsen <andreas@andreasjacobsen.com>
Signed-off-by: John Keeping <john@keeping.me.uk>
Tested-by: Andreas Jacobsen <andreas@andreasjacobsen.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Commit aacecc3 (merge-tree: don't print entries that match "local" -
2013-04-07) had a typo causing the "same in both" check to be incorrect
and check if both the base and "their" versions are removed instead of
checking that both the "our" and "their" versions are removed. Fix
this.
Reported-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Test-written-by: René Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The documentation says:
the output from the command omits entries that match the
<branch1> tree.
But currently "added in branch1" and "removed in branch1" (both while
unchanged in branch2) do print output. Change this so that the
behaviour matches the documentation.
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When calculating whether there is a d/f conflict, the calculation of
whether both sides are directories generates an incorrect references
mask because it does not use the loop index to set the correct bit.
Fix this typo.
Signed-off-by: John Keeping <john@keeping.me.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
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>
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>
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>
In order to fix the warning, we add a new "merge-file.h" header
containing the extern declaration of the merge_file() function,
and include the header in the source files that require the
declaration.
Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Fix warnings from 'make check'.
- These files don't include 'builtin.h' causing sparse to complain that
cmd_* isn't declared:
builtin/clone.c:364, builtin/fetch-pack.c:797,
builtin/fmt-merge-msg.c:34, builtin/hash-object.c:78,
builtin/merge-index.c:69, builtin/merge-recursive.c:22
builtin/merge-tree.c:341, builtin/mktag.c:156, builtin/notes.c:426
builtin/notes.c:822, builtin/pack-redundant.c:596,
builtin/pack-refs.c:10, builtin/patch-id.c:60, builtin/patch-id.c:149,
builtin/remote.c:1512, builtin/remote-ext.c:240,
builtin/remote-fd.c:53, builtin/reset.c:236, builtin/send-pack.c:384,
builtin/unpack-file.c:25, builtin/var.c:75
- These files have symbols which should be marked static since they're
only file scope:
submodule.c:12, diff.c:631, replace_object.c:92, submodule.c:13,
submodule.c:14, trace.c:78, transport.c:195, transport-helper.c:79,
unpack-trees.c:19, url.c:3, url.c:18, url.c:104, url.c:117, url.c:123,
url.c:129, url.c:136, thread-utils.c:21, thread-utils.c:48
- These files redeclare symbols to be different types:
builtin/index-pack.c:210, parse-options.c:564, parse-options.c:571,
usage.c:49, usage.c:58, usage.c:63, usage.c:72
- These files use a literal integer 0 when they really should use a NULL
pointer:
daemon.c:663, fast-import.c:2942, imap-send.c:1072, notes-merge.c:362
While we're in the area, clean up some unused #includes in builtin files
(mostly exec_cmd.h).
Signed-off-by: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
15b4f7a (merge-tree: use ll_merge() not xdl_merge(), 2010-01-16)
introduced a regression to merge-tree to cause it to segfault when merging
files which existed in one branch, but not in the other or in the
merge-base. This was caused by referencing entry->path at a time when
entry was known to be possibly-NULL.
To correct the problem, we save the path of the entry we came in with,
as the path should be the same among all the stages no matter which
sides are involved in the merge.
Signed-off-by: Will Palmer <wmpalmer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This shrinks the top-level directory a bit, and makes it much more
pleasant to use auto-completion on the thing. Instead of
[torvalds@nehalem git]$ em buil<tab>
Display all 180 possibilities? (y or n)
[torvalds@nehalem git]$ em builtin-sh
builtin-shortlog.c builtin-show-branch.c builtin-show-ref.c
builtin-shortlog.o builtin-show-branch.o builtin-show-ref.o
[torvalds@nehalem git]$ em builtin-shor<tab>
builtin-shortlog.c builtin-shortlog.o
[torvalds@nehalem git]$ em builtin-shortlog.c
you get
[torvalds@nehalem git]$ em buil<tab> [type]
builtin/ builtin.h
[torvalds@nehalem git]$ em builtin [auto-completes to]
[torvalds@nehalem git]$ em builtin/sh<tab> [type]
shortlog.c shortlog.o show-branch.c show-branch.o show-ref.c show-ref.o
[torvalds@nehalem git]$ em builtin/sho [auto-completes to]
[torvalds@nehalem git]$ em builtin/shor<tab> [type]
shortlog.c shortlog.o
[torvalds@nehalem git]$ em builtin/shortlog.c
which doesn't seem all that different, but not having that annoying
break in "Display all 180 possibilities?" is quite a relief.
NOTE! If you do this in a clean tree (no object files etc), or using an
editor that has auto-completion rules that ignores '*.o' files, you
won't see that annoying 'Display all 180 possibilities?' message - it
will just show the choices instead. I think bash has some cut-off
around 100 choices or something.
So the reason I see this is that I'm using an odd editory, and thus
don't have the rules to cut down on auto-completion. But you can
simulate that by using 'ls' instead, or something similar.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This call should have been removed when the utility was made a builtin by
907a7cb.
Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
ll_merge() interface was designed to merge contents under git control
while taking per-path attributes into account. Update the three-way
merge implementation used by merge-tree to use it.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Programs that use git_config need to find the global configuration.
When runtime prefix computation is enabled, this requires that
git_extract_argv0_path() is called early in the program's main().
This commit adds the necessary calls.
Signed-off-by: Steffen Prohaska <prohaska@zib.de>
Acked-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Many call sites immediately initialize allocated memory with zero after
calling xmalloc. A single call to xcalloc can replace this two-call
sequence.
Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
This makes the traverse_trees() entry comparator routine use the more
relaxed form of name comparison that considers files and directories
with the same name identical.
We pass in a separate mask for just the directory entries, so that the
callback routine can decide (if it wants to) to only handle one or the
other type, but generally most (all?) users are expected to really want
to see the case of a name 'foo' showing up in one tree as a file and in
another as a directory at the same time.
In particular, moving 'unpack_trees()' over to use this tree traversal
mechanism requires this.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This allows the callback to return an error value, but it can also
specify which of the tree entries that it actually used up by returning
a positive mask value.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This makes the calling convention a bit less obvious, but a lot more
flexible. Instead of allocating and extending a new 'base' string, we
just link the top-most name into a linked list of the 'info' structure
when traversing a subdirectory, and we can generate the basename by
following the list.
Perhaps even more importantly, the linked list of info structures also
gives us a place to naturally save off other information than just the
directory name.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This inserts a new function xdi_diff() that currently does not
do anything other than calling the underlying xdl_diff() to the
callchain of current callers of xdl_diff() function.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The instances of xdemitconf_t were initialized member by member.
Instead, initialize them to all zero, so we do not have
to update those places each time we introduce a new member.
[jc: minimally fixed by getting rid of a new global]
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Since we have the "tree_entry_len()" helper function these days, and
don't need to do a full strlen(), there's no point in saving the path
length - it's just redundant information.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
We currently have two parallel notation for dealing with object types
in the code: a string and a numerical value. One of them is obviously
redundent, and the most used one requires more stack space and a bunch
of strcmp() all over the place.
This is an initial step for the removal of the version using a char array
found in object reading code paths. The patch is unfortunately large but
there is no sane way to split it in smaller parts without breaking the
system.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
describe, git: Handle argc==0 case the same way as argc==1.
merge-tree: Refuse excessive arguments.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Call setup_git_directory() to make these commands work in subdirectory.
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Like xmalloc and xrealloc xstrdup dies with a useful message if
the native strdup() implementation returns NULL rather than a
valid pointer.
I just tried to use xstrdup in new code and found it to be missing.
However I expected it to be present as xmalloc and xrealloc are
already commonly used throughout the code.
[jc: removed the part that deals with last_XXX, which I am
finding more and more dubious these days.]
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Introduces global inline:
hashcmp(const unsigned char *sha1, const unsigned char *sha2)
Uses memcmp for comparison and returns the result based on the length of
the hash name (a future runtime decision).
Acked-by: Alex Riesen <raa.lkml@gmail.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This fleshes out the code that generates a three-way merge of a set of
blobs.
It still actually does the three-way merge using an external executable
(ie just calling "merge"), but the interfaces have been cleaned up a lot
and are now fully based on the 'mmfile_t' interface, so if libxdiff were
to ever grow a compatible three-way-merge, it could probably be directly
plugged in.
It also uses the previous XDL_EMIT_COMMON functionality extension to
libxdiff to generate a made-up base file for the merge for the case where
no base file previously existed. This should be equivalent to what we
currently do in git-merge-one-file.sh:
diff -u -La/$orig -Lb/$orig $orig $src2 | git-apply --no-add
except it should be much simpler and can be done using the direct libxdiff
interfaces.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
This changes how "git-merge-tree" works in two ways:
- instead of printing things out as we walk the trees, we save the
results in memory.
- when we've walked the tree fully, we print out the results in a more
explicit way, describing the data.
This is basically preparatory work for extending the git-merge-tree
functionality in interesting directions.
In particular, git-merge-tree is also how you would create a diff between
two trees _without_ necessarily creating the merge commit itself. In other
words, if you were to just wonder what another branch adds, you should be
able to (eventually) just do
git merge-tree -p $base HEAD $otherbranch
to generate a diff of what the merge would look like. The current merge
tree already basically has all the smarts for this, and the explanation of
the results just means that hopefully somebody else than me could do the
boring work.
(You'd basically be able to do the above diff by just changing the
printout format for the explanation, and making the "changed in both"
first do a three-way merge before it diffs the result).
The other thing that the in-memory format allows is rename detection
(which the current code does not do). That's the basic reason why we don't
want to just explain the differences as we go along - because we want to
be able to look at the _other_ differences to see whether the reason an
entry got deleted in either branch was perhaps because it got added in
another place..
Rename detection should be a fairly trivial pass in between the tree
diffing and the explanation.
In the meantime, this doesn't actually do anything new, it just outputs
the information in a more verbose manner.
For an example merge, commit 5ab2c0a475 in
the git tree works well and shows renames, along with true removals and
additions and files that got changed in both branches. To see that as a
tree merge, do:
git-merge-tree 64e86c57c5c23745928e47e3
where the two last ones are the tips that got merged, and the first one is
the merge base.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Somebody on the #git channel complained that the sha1_to_hex() thing uses
a static buffer which caused an error message to show the same hex output
twice instead of showing two different ones.
That's pretty easily rectified by making it uses a simple LRU of a few
buffers, which also allows some other users (that were aware of the buffer
re-use) to be written in a more straightforward manner.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
Introduce tree-walk.[ch] and move "struct tree_desc" and
associated functions from various places.
Rename DIFF_FILE_CANON_MODE(mode) macro to canon_mode(mode) and
move it to cache.h. This macro returns the canonicalized
st_mode value in the host byte order for files, symlinks and
directories -- to be compared with a tree_desc entry.
create_ce_mode(mode) in cache.h is similar but is intended to be
used for index entries (so it does not work for directories) and
returns the value in the network byte order.
Signed-off-by: Junio C Hamano <junkio@cox.net>
It's actually very useful for other things too. Notably, we could do the
combined diff a lot more efficiently with this.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
On Tue, 14 Feb 2006, Linus Torvalds wrote:
>
> Here, btw, is the trivial diff to turn my previous "tree-resolve" into a
> "resolve tree relative to the current branch".
Gaah. It was trivial, and it happened to work fine for my test-case, but
when I started looking at not doing that extremely aggressive subdirectory
merging, that showed a few other issues...
So in case people want to try, here's a third patch. Oh, and it's against
my _original_ path, not incremental to the middle one (ie both patches two
and three are against patch #1, it's not a nice series).
Now I'm really done, and won't be sending out any more patches today.
Sorry for the noise.
Linus
Signed-off-by: Junio C Hamano <junkio@cox.net>
On Tue, 14 Feb 2006, Junio C Hamano wrote:
> Linus Torvalds <torvalds@osdl.org> writes:
>
> > If somebody is interested in making the "lots of filename changes" case go
> > fast, I'd be more than happy to walk them through what they'd need to
> > change. I'm just not horribly motivated to do it myself. Hint, hint.
>
> In case anybody is wondering, I share the same feeling. I
> cannot say I'd be "more than happy to" clean up potential
> breakages during the development of such changes, but if the
> change eventually would help certain use cases, I can be
> persuaded to help debugging such a mess ;-).
Actually, I got interested in seeing how hard this is, and wrote a simple
first cut at doing a tree-optimized merger.
Let me shout a bit first:
THIS IS WORKING CODE, BUT BE CAREFUL: IT'S A TECHNOLOGY DEMONSTRATION
RATHER THAN THE FINAL PRODUCT!
With that out of the way, let me descibe what this does (and then describe
the missing parts).
This is basically a three-way merge that works entirely on the "tree"
level, rather than on the index. A lot of the _concepts_ are the same,
though, and if you're familiar with the results of an index merge, some of
the output will make more sense.
You give it three trees: the base tree (tree 0), and the two branches to
be merged (tree 1 and tree 2 respectively). It will then walk these three
trees, and resolve them as it goes along.
The interesting part is:
- it can resolve whole sub-directories in one go, without actually even
looking recursively at them. A whole subdirectory will resolve the same
way as any individual files will (although that may need some
modification, see later).
- if it has a "content conflict", for subdirectories that means "try to
do a recursive tree merge", while for non-subdirectories it's just a
content conflict and we'll output the stage 1/2/3 information.
- a successful merge will output a single stage 0 ("merged") entry,
potentially for a whole subdirectory.
- it outputs all the resolve information on stdout, so something like the
recursive resolver can pretty easily parse it all.
Now, the caveats:
- we probably need to be more careful about subdirectory resolves. The
trivial case (both branches have the exact same subdirectory) is a
trivial resolve, but the other cases ("branch1 matches base, branch2 is
different" probably can't be silently just resolved to the "branch2"
subdirectory state, since it might involve renames into - or out of -
that subdirectory)
- we do not track the current index file at all, so this does not do the
"check that index matches branch1" logic that the three-way merge in
git-read-tree does. The theory is that we'd do a full three-way merge
(ignoring the index and working directory), and then to update the
working tree, we'd do a two-way "git-read-tree branch1->result"
- I didn't actually make it do all the trivial resolve cases that
git-read-tree does. It's a technology demonstration.
Finally (a more serious caveat):
- doing things through stdout may end up being so expensive that we'd
need to do something else. In particular, it's likely that I should
not actually output the "merge results", but instead output a "merge
results as they _differ_ from branch1"
However, I think this patch is already interesting enough that people who
are interested in merging trees might want to look at it. Please keep in
mind that tech _demo_ part, and in particular, keep in mind the final
"serious caveat" part.
In many ways, the really _interesting_ part of a merge is not the result,
but how it _changes_ the branch we're merging into. That's particularly
important as it should hopefully also mean that the output size for any
reasonable case is minimal (and tracks what we actually need to do to the
current state to create the final result).
The code very much is organized so that doing the result as a "diff
against branch1" should be quite easy/possible. I was actually going to do
it, but I decided that it probably makes the output harder to read. I
dunno.
Anyway, let's think about this kind of approach.. Note how the code itself
is actually quite small and short, although it's prbably pretty "dense".
As an interesting test-case, I'd suggest this merge in the kernel:
git-merge-tree $(git-merge-base 4cbf876 7d2babc) 4cbf876 7d2babc
which resolves beautifully (there are no actual file-level conflicts), and
you can look at the output of that command to start thinking about what
it does.
The interesting part (perhaps) is that timing that command for me shows
that it takes all of 0.004 seconds.. (the git-merge-base thing takes
considerably more ;)
The point is, we _can_ do the actual merge part really really quickly.
Linus
PS. Final note: when I say that it is "WORKING CODE", that is obviously by
my standards. IOW, I tested it once and it gave reasonable results - so it
must be perfect.
Whether it works for anybody else, or indeed for any other test-case, is
not my problem ;)
Signed-off-by: Junio C Hamano <junkio@cox.net>
It's there in the history if somebody wants to resurrect it, but it
seems to have been successfully superceded by the new and improved
index-merge thing, where we do all merging entirely in the index.
This adds '-z' to merge-tree and changes its default line termination to
LF to make it consistent with your other recent changes.
Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
John Keeping