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Merge branch 'js/merge' 

* js/merge:
  merge-recursive: add/add really is modify/modify with an empty base
  Get rid of the dependency on RCS' merge program
  merge-file: support -p and -q; fix compile warnings
  Add builtin merge-file, a minimal replacement for RCS merge
  xdl_merge(): fix and simplify conflict handling
  xdl_merge(): fix thinko
  xdl_merge(): fix an off-by-one bug
  merge-recursive: use xdl_merge().
  xmerge: make return value from xdl_merge() more usable.
  xdiff: add xdl_merge()
maint
Junio C Hamano 2006-12-13 10:46:23 -08:00
parent 37adac765a f953831e03
commit e4d45dd3bb
19 changed files with 708 additions and 172 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
.gitignore vendored
View File

@ -60,6 +60,7 @@ git-mailsplit
git-merge
git-merge-base
git-merge-index
git-merge-file
git-merge-tree
git-merge-octopus
git-merge-one-file

4
Documentation/git-merge-index.txt
View File

@ -40,8 +40,8 @@ If "git-merge-index" is called with multiple <file>s (or -a) then it
processes them in turn only stopping if merge returns a non-zero exit
code.

Typically this is run with the a script calling the merge command from
the RCS package.
Typically this is run with the a script calling git's imitation of
the merge command from the RCS package.

A sample script called "git-merge-one-file" is included in the
distribution.

9
INSTALL
View File

@ -82,15 +82,6 @@ Issues of note:
do that even if it wasn't for git. There's no point in living
in the dark ages any more.

- "merge", the standard UNIX three-way merge program. It usually
comes with the "rcs" package on most Linux distributions, so if
you have a developer install you probably have it already, but a
"graphical user desktop" install might have left it out.

You'll only need the merge program if you do development using
git, and if you only use git to track other peoples work you'll
never notice the lack of it.

- "wish", the Tcl/Tk windowing shell is used in gitk to show the
history graphically


4
Makefile
View File

@ -279,6 +279,7 @@ BUILTIN_OBJS = \
builtin-ls-tree.o \
builtin-mailinfo.o \
builtin-mailsplit.o \
builtin-merge-file.o \
builtin-mv.o \
builtin-name-rev.o \
builtin-pack-objects.o \
@ -737,7 +738,8 @@ $(DIFF_OBJS): diffcore.h
$(LIB_FILE): $(LIB_OBJS)
rm -f $@ && $(AR) rcs $@ $(LIB_OBJS)

XDIFF_OBJS=xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o
XDIFF_OBJS=xdiff/xdiffi.o xdiff/xprepare.o xdiff/xutils.o xdiff/xemit.o \
xdiff/xmerge.o
$(XDIFF_OBJS): xdiff/xinclude.h xdiff/xmacros.h xdiff/xdiff.h xdiff/xtypes.h \
xdiff/xutils.h xdiff/xprepare.h xdiff/xdiffi.h xdiff/xemit.h


79
builtin-merge-file.c Normal file
View File

@ -0,0 +1,79 @@
#include "cache.h"
#include "xdiff/xdiff.h"

static const char merge_file_usage[] =
"git merge-file [-p | --stdout] [-q | --quiet] [-L name1 [-L orig [-L name2]]] file1 orig_file file2";

static int read_file(mmfile_t *ptr, const char *filename)
{
struct stat st;
FILE *f;

if (stat(filename, &st))
return error("Could not stat %s", filename);
if ((f = fopen(filename, "rb")) == NULL)
return error("Could not open %s", filename);
ptr->ptr = xmalloc(st.st_size);
if (fread(ptr->ptr, st.st_size, 1, f) != 1)
return error("Could not read %s", filename);
fclose(f);
ptr->size = st.st_size;
return 0;
}

int cmd_merge_file(int argc, char **argv, char **envp)
{
char *names[3];
mmfile_t mmfs[3];
mmbuffer_t result = {NULL, 0};
xpparam_t xpp = {XDF_NEED_MINIMAL};
int ret = 0, i = 0, to_stdout = 0;

while (argc > 4) {
if (!strcmp(argv[1], "-L") && i < 3) {
names[i++] = argv[2];
argc--;
argv++;
} else if (!strcmp(argv[1], "-p") ||
!strcmp(argv[1], "--stdout"))
to_stdout = 1;
else if (!strcmp(argv[1], "-q") ||
!strcmp(argv[1], "--quiet"))
freopen("/dev/null", "w", stderr);
else
usage(merge_file_usage);
argc--;
argv++;
}

if (argc != 4)
usage(merge_file_usage);

for (; i < 3; i++)
names[i] = argv[i + 1];

for (i = 0; i < 3; i++)
if (read_file(mmfs + i, argv[i + 1]))
return -1;

ret = xdl_merge(mmfs + 1, mmfs + 0, names[0], mmfs + 2, names[2],
&xpp, XDL_MERGE_ZEALOUS, &result);

for (i = 0; i < 3; i++)
free(mmfs[i].ptr);

if (ret >= 0) {
char *filename = argv[1];
FILE *f = to_stdout ? stdout : fopen(filename, "wb");

if (!f)
ret = error("Could not open %s for writing", filename);
else if (fwrite(result.ptr, result.size, 1, f) != 1)
ret = error("Could not write to %s", filename);
else if (fclose(f))
ret = error("Could not close %s", filename);
free(result.ptr);
}

return ret;
}

1
builtin.h
View File

@ -42,6 +42,7 @@ extern int cmd_ls_files(int argc, const char **argv, const char *prefix);
extern int cmd_ls_tree(int argc, const char **argv, const char *prefix);
extern int cmd_mailinfo(int argc, const char **argv, const char *prefix);
extern int cmd_mailsplit(int argc, const char **argv, const char *prefix);
extern int cmd_merge_file(int argc, const char **argv, const char *prefix);
extern int cmd_mv(int argc, const char **argv, const char *prefix);
extern int cmd_name_rev(int argc, const char **argv, const char *prefix);
extern int cmd_pack_objects(int argc, const char **argv, const char *prefix);

2
git-cvsserver.perl
View File

@ -946,7 +946,7 @@ sub req_update

$log->debug("Temporary directory for merge is $dir");

my $return = system("merge", $file_local, $file_old, $file_new);
my $return = system("git merge-file", $file_local, $file_old, $file_new);
$return >>= 8;

if ( $return == 0 )

2
git-rerere.perl
View File

@ -154,7 +154,7 @@ sub find_conflict {
sub merge {
my ($name, $path) = @_;
record_preimage($path, "$rr_dir/$name/thisimage");
unless (system('merge', map { "$rr_dir/$name/${_}image" }
unless (system('git merge-file', map { "$rr_dir/$name/${_}image" }
qw(this pre post))) {
my $in;
open $in, "<$rr_dir/$name/thisimage" or

1
git.c
View File

@ -247,6 +247,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
{ "ls-tree", cmd_ls_tree, RUN_SETUP },
{ "mailinfo", cmd_mailinfo },
{ "mailsplit", cmd_mailsplit },
{ "merge-file", cmd_merge_file },
{ "mv", cmd_mv, RUN_SETUP },
{ "name-rev", cmd_name_rev, RUN_SETUP },
{ "pack-objects", cmd_pack_objects, RUN_SETUP },

2
git.spec.in
View File

@ -24,7 +24,7 @@ This is a dummy package which brings in all subpackages.
%package core
Summary: Core git tools
Group: Development/Tools
Requires: zlib >= 1.2, rsync, rcs, curl, less, openssh-clients, expat
Requires: zlib >= 1.2, rsync, curl, less, openssh-clients, expat
%description core
This is a stupid (but extremely fast) directory content manager. It
doesn't do a whole lot, but what it _does_ do is track directory

73
merge-file.c
View File

@ -3,52 +3,6 @@
#include "xdiff-interface.h"
#include "blob.h"

static void rm_temp_file(const char *filename)
{
unlink(filename);
free((void *)filename);
}

static const char *write_temp_file(mmfile_t *f)
{
int fd;
const char *tmp = getenv("TMPDIR");
char *filename;

if (!tmp)
tmp = "/tmp";
filename = mkpath("%s/%s", tmp, "git-tmp-XXXXXX");
fd = mkstemp(filename);
if (fd < 0)
return NULL;
filename = xstrdup(filename);
if (f->size != xwrite(fd, f->ptr, f->size)) {
rm_temp_file(filename);
return NULL;
}
close(fd);
return filename;
}

static void *read_temp_file(const char *filename, unsigned long *size)
{
struct stat st;
char *buf = NULL;
int fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
if (!fstat(fd, &st)) {
*size = st.st_size;
buf = xmalloc(st.st_size);
if (st.st_size != xread(fd, buf, st.st_size)) {
free(buf);
buf = NULL;
}
}
close(fd);
return buf;
}

static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
{
void *buf;
@ -72,22 +26,19 @@ static void free_mmfile(mmfile_t *f)

static void *three_way_filemerge(mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
{
void *res;
const char *t1, *t2, *t3;
mmbuffer_t res;
xpparam_t xpp;
int merge_status;

t1 = write_temp_file(base);
t2 = write_temp_file(our);
t3 = write_temp_file(their);
res = NULL;
if (t1 && t2 && t3) {
int code = run_command("merge", t2, t1, t3, NULL);
if (!code || code == -1)
res = read_temp_file(t2, size);
}
rm_temp_file(t1);
rm_temp_file(t2);
rm_temp_file(t3);
return res;
memset(&xpp, 0, sizeof(xpp));
merge_status = xdl_merge(base, our, ".our", their, ".their",
&xpp, XDL_MERGE_ZEALOUS, &res);

if (merge_status < 0)
return NULL;

*size = res.size;
return res.ptr;
}

static int common_outf(void *priv_, mmbuffer_t *mb, int nbuf)

130
merge-recursive.c
View File

@ -21,6 +21,7 @@
#include "tag.h"
#include "unpack-trees.h"
#include "path-list.h"
#include "xdiff-interface.h"

/*
* A virtual commit has
@ -604,24 +605,21 @@ struct merge_file_info
merge:1;
};

static char *git_unpack_file(const unsigned char *sha1, char *path)
static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
{
void *buf;
char type[20];
unsigned long size;
int fd;
char type[20];

buf = read_sha1_file(sha1, type, &size);
if (!buf || strcmp(type, blob_type))
if (!hashcmp(sha1, null_sha1)) {
mm->ptr = xstrdup("");
mm->size = 0;
return;
}

mm->ptr = read_sha1_file(sha1, type, &size);
if (!mm->ptr || strcmp(type, blob_type))
die("unable to read blob object %s", sha1_to_hex(sha1));

strcpy(path, ".merge_file_XXXXXX");
fd = mkstemp(path);
if (fd < 0)
die("unable to create temp-file");
flush_buffer(fd, buf, size);
close(fd);
return path;
mm->size = size;
}

static struct merge_file_info merge_file(struct diff_filespec *o,
@ -652,49 +650,41 @@ static struct merge_file_info merge_file(struct diff_filespec *o,
else if (sha_eq(b->sha1, o->sha1))
hashcpy(result.sha, a->sha1);
else if (S_ISREG(a->mode)) {
int code = 1, fd;
struct stat st;
char orig[PATH_MAX];
char src1[PATH_MAX];
char src2[PATH_MAX];
const char *argv[] = {
"merge", "-L", NULL, "-L", NULL, "-L", NULL,
NULL, NULL, NULL,
NULL
};
char *la, *lb, *lo;
mmfile_t orig, src1, src2;
mmbuffer_t result_buf;
xpparam_t xpp;
char *name1, *name2;
int merge_status;

git_unpack_file(o->sha1, orig);
git_unpack_file(a->sha1, src1);
git_unpack_file(b->sha1, src2);
name1 = xstrdup(mkpath("%s/%s", branch1, a->path));
name2 = xstrdup(mkpath("%s/%s", branch2, b->path));

argv[2] = la = xstrdup(mkpath("%s/%s", branch1, a->path));
argv[6] = lb = xstrdup(mkpath("%s/%s", branch2, b->path));
argv[4] = lo = xstrdup(mkpath("orig/%s", o->path));
argv[7] = src1;
argv[8] = orig;
argv[9] = src2,
fill_mm(o->sha1, &orig);
fill_mm(a->sha1, &src1);
fill_mm(b->sha1, &src2);

code = run_command_v(10, argv);
memset(&xpp, 0, sizeof(xpp));
merge_status = xdl_merge(&orig,
&src1, name1,
&src2, name2,
&xpp, XDL_MERGE_ZEALOUS,
&result_buf);
free(name1);
free(name2);
free(orig.ptr);
free(src1.ptr);
free(src2.ptr);

free(la);
free(lb);
free(lo);
if (code && code < -256) {
die("Failed to execute 'merge'. merge(1) is used as the "
"file-level merge tool. Is 'merge' in your path?");
}
fd = open(src1, O_RDONLY);
if (fd < 0 || fstat(fd, &st) < 0 ||
index_fd(result.sha, fd, &st, 1,
"blob"))
die("Unable to add %s to database", src1);
if ((merge_status < 0) || !result_buf.ptr)
die("Failed to execute internal merge");

unlink(orig);
unlink(src1);
unlink(src2);
if (write_sha1_file(result_buf.ptr, result_buf.size,
blob_type, result.sha))
die("Unable to add %s to database",
a->path);

result.clean = WEXITSTATUS(code) == 0;
free(result_buf.ptr);
result.clean = (merge_status == 0);
} else {
if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
die("cannot merge modes?");
@ -1061,38 +1051,17 @@ static int process_entry(const char *path, struct stage_data *entry,
output("Adding %s", path);
update_file(1, sha, mode, path);
}
} else if (!o_sha && a_sha && b_sha) {
/* Case C: Added in both (check for same permissions). */
if (sha_eq(a_sha, b_sha)) {
if (a_mode != b_mode) {
clean_merge = 0;
output("CONFLICT: File %s added identically in both branches, "
"but permissions conflict %06o->%06o",
path, a_mode, b_mode);
output("CONFLICT: adding with permission: %06o", a_mode);
update_file(0, a_sha, a_mode, path);
} else {
/* This case is handled by git-read-tree */
assert(0 && "This case must be handled by git-read-tree");
}
} else {
const char *new_path1, *new_path2;
clean_merge = 0;
new_path1 = unique_path(path, branch1);
new_path2 = unique_path(path, branch2);
output("CONFLICT (add/add): File %s added non-identically "
"in both branches. Adding as %s and %s instead.",
path, new_path1, new_path2);
remove_file(0, path, 0);
update_file(0, a_sha, a_mode, new_path1);
update_file(0, b_sha, b_mode, new_path2);
}

} else if (o_sha && a_sha && b_sha) {
} else if (a_sha && b_sha) {
/* Case C: Added in both (check for same permissions) and */
/* case D: Modified in both, but differently. */
const char *reason = "content";
struct merge_file_info mfi;
struct diff_filespec o, a, b;

if (!o_sha) {
reason = "add/add";
o_sha = (unsigned char *)null_sha1;
}
output("Auto-merging %s", path);
o.path = a.path = b.path = (char *)path;
hashcpy(o.sha1, o_sha);
@ -1109,7 +1078,8 @@ static int process_entry(const char *path, struct stage_data *entry,
update_file(1, mfi.sha, mfi.mode, path);
else {
clean_merge = 0;
output("CONFLICT (content): Merge conflict in %s", path);
output("CONFLICT (%s): Merge conflict in %s",
reason, path);

if (index_only)
update_file(0, mfi.sha, mfi.mode, path);

14
t/t0000-basic.sh
View File

@ -19,11 +19,7 @@ modification *should* take notice and update the test vectors here.
'

################################################################
# It appears that people are getting bitten by not installing
# 'merge' (usually part of RCS package in binary distributions).
# Check this and error out before running any tests. Also catch
# the bogosity of trying to run tests without building while we
# are at it.
# It appears that people try to run tests without building...

../git >/dev/null
if test $? != 1
@ -32,14 +28,6 @@ then
exit 1
fi

merge >/dev/null 2>/dev/null
if test $? = 127
then
echo >&2 'You do not seem to have "merge" installed.
Please check INSTALL document.'
exit 1
fi

. ./test-lib.sh

################################################################

116
t/t6023-merge-file.sh Normal file
View File

@ -0,0 +1,116 @@
#!/bin/sh

test_description='RCS merge replacement: merge-file'
. ./test-lib.sh

cat > orig.txt << EOF
Dominus regit me,
et nihil mihi deerit.
In loco pascuae ibi me collocavit,
super aquam refectionis educavit me;
animam meam convertit,
deduxit me super semitas jusitiae,
propter nomen suum.
EOF

cat > new1.txt << EOF
Dominus regit me,
et nihil mihi deerit.
In loco pascuae ibi me collocavit,
super aquam refectionis educavit me;
animam meam convertit,
deduxit me super semitas jusitiae,
propter nomen suum.
Nam et si ambulavero in medio umbrae mortis,
non timebo mala, quoniam tu mecum es:
virga tua et baculus tuus ipsa me consolata sunt.
EOF

cat > new2.txt << EOF
Dominus regit me, et nihil mihi deerit.
In loco pascuae ibi me collocavit,
super aquam refectionis educavit me;
animam meam convertit,
deduxit me super semitas jusitiae,
propter nomen suum.
EOF

cat > new3.txt << EOF
DOMINUS regit me,
et nihil mihi deerit.
In loco pascuae ibi me collocavit,
super aquam refectionis educavit me;
animam meam convertit,
deduxit me super semitas jusitiae,
propter nomen suum.
EOF

cat > new4.txt << EOF
Dominus regit me, et nihil mihi deerit.
In loco pascuae ibi me collocavit,
super aquam refectionis educavit me;
animam meam convertit,
deduxit me super semitas jusitiae,
EOF
echo -n "propter nomen suum." >> new4.txt

cp new1.txt test.txt
test_expect_success "merge without conflict" \
"git-merge-file test.txt orig.txt new2.txt"

cp new1.txt test2.txt
test_expect_success "merge without conflict (missing LF at EOF)" \
"git-merge-file test2.txt orig.txt new2.txt"

test_expect_success "merge result added missing LF" \
"diff -u test.txt test2.txt"

cp test.txt backup.txt
test_expect_failure "merge with conflicts" \
"git-merge-file test.txt orig.txt new3.txt"

cat > expect.txt << EOF
<<<<<<< test.txt
Dominus regit me, et nihil mihi deerit.
=======
DOMINUS regit me,
et nihil mihi deerit.
>>>>>>> new3.txt
In loco pascuae ibi me collocavit,
super aquam refectionis educavit me;
animam meam convertit,
deduxit me super semitas jusitiae,
propter nomen suum.
Nam et si ambulavero in medio umbrae mortis,
non timebo mala, quoniam tu mecum es:
virga tua et baculus tuus ipsa me consolata sunt.
EOF

test_expect_success "expected conflict markers" "diff -u test.txt expect.txt"

cp backup.txt test.txt
test_expect_failure "merge with conflicts, using -L" \
"git-merge-file -L 1 -L 2 test.txt orig.txt new3.txt"

cat > expect.txt << EOF
<<<<<<< 1
Dominus regit me, et nihil mihi deerit.
=======
DOMINUS regit me,
et nihil mihi deerit.
>>>>>>> new3.txt
In loco pascuae ibi me collocavit,
super aquam refectionis educavit me;
animam meam convertit,
deduxit me super semitas jusitiae,
propter nomen suum.
Nam et si ambulavero in medio umbrae mortis,
non timebo mala, quoniam tu mecum es:
virga tua et baculus tuus ipsa me consolata sunt.
EOF

test_expect_success "expected conflict markers, with -L" \
"diff -u test.txt expect.txt"

test_done

12
t/t6024-recursive-merge.sh Executable file → Normal file
View File

@ -58,9 +58,19 @@ GIT_AUTHOR_DATE="2006-12-12 23:00:08" git commit -m F

test_expect_failure "combined merge conflicts" "git merge -m final G"

cat > expect << EOF
<<<<<<< HEAD/a1
F
=======
G
>>>>>>> 26f86b677eb03d4d956dbe108b29cb77061c1e73/a1
EOF

test_expect_success "result contains a conflict" "diff -u expect a1"

git ls-files --stage > out
cat > expect << EOF
100644 f70f10e4db19068f79bc43844b49f3eece45c4e8 1 a1
100644 f16f906ab60483c100d1241dfc39868de9ec9fcb 1 a1
100644 cf84443e49e1b366fac938711ddf4be2d4d1d9e9 2 a1
100644 fd7923529855d0b274795ae3349c5e0438333979 3 a1
EOF

7
xdiff/xdiff.h
View File

@ -49,6 +49,9 @@ extern "C" {
#define XDL_BDOP_CPY 2
#define XDL_BDOP_INSB 3

#define XDL_MERGE_MINIMAL 0
#define XDL_MERGE_EAGER 1
#define XDL_MERGE_ZEALOUS 2

typedef struct s_mmfile {
char *ptr;
@ -90,6 +93,10 @@ long xdl_mmfile_size(mmfile_t *mmf);
int xdl_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
xdemitconf_t const *xecfg, xdemitcb_t *ecb);

int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
mmfile_t *mf2, const char *name2,
xpparam_t const *xpp, int level, mmbuffer_t *result);

#ifdef __cplusplus
}
#endif /* #ifdef __cplusplus */

3
xdiff/xdiffi.c
View File

@ -45,7 +45,6 @@ static long xdl_split(unsigned long const *ha1, long off1, long lim1,
long *kvdf, long *kvdb, int need_min, xdpsplit_t *spl,
xdalgoenv_t *xenv);
static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1, long chg2);
static int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags);



@ -397,7 +396,7 @@ static xdchange_t *xdl_add_change(xdchange_t *xscr, long i1, long i2, long chg1,
}


static int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) {
int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags) {
long ix, ixo, ixs, ixref, grpsiz, nrec = xdf->nrec;
char *rchg = xdf->rchg, *rchgo = xdfo->rchg;
xrecord_t **recs = xdf->recs;

1
xdiff/xdiffi.h
View File

@ -50,6 +50,7 @@ int xdl_recs_cmp(diffdata_t *dd1, long off1, long lim1,
long *kvdf, long *kvdb, int need_min, xdalgoenv_t *xenv);
int xdl_do_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp,
xdfenv_t *xe);
int xdl_change_compact(xdfile_t *xdf, xdfile_t *xdfo, long flags);
int xdl_build_script(xdfenv_t *xe, xdchange_t **xscr);
void xdl_free_script(xdchange_t *xscr);
int xdl_emit_diff(xdfenv_t *xe, xdchange_t *xscr, xdemitcb_t *ecb,

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xdiff/xmerge.c Normal file
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/*
* LibXDiff by Davide Libenzi ( File Differential Library )
* Copyright (C) 2003-2006 Davide Libenzi, Johannes E. Schindelin
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Davide Libenzi <davidel@xmailserver.org>
*
*/

#include "xinclude.h"

typedef struct s_xdmerge {
struct s_xdmerge *next;
/*
* 0 = conflict,
* 1 = no conflict, take first,
* 2 = no conflict, take second.
*/
int mode;
long i1, i2;
long chg1, chg2;
} xdmerge_t;

static int xdl_append_merge(xdmerge_t **merge, int mode,
long i1, long chg1, long i2, long chg2)
{
xdmerge_t *m = *merge;
if (m && (i1 <= m->i1 + m->chg1 || i2 <= m->i2 + m->chg2)) {
if (mode != m->mode)
m->mode = 0;
m->chg1 = i1 + chg1 - m->i1;
m->chg2 = i2 + chg2 - m->i2;
} else {
m = xdl_malloc(sizeof(xdmerge_t));
if (!m)
return -1;
m->next = NULL;
m->mode = mode;
m->i1 = i1;
m->chg1 = chg1;
m->i2 = i2;
m->chg2 = chg2;
if (*merge)
(*merge)->next = m;
*merge = m;
}
return 0;
}

static int xdl_cleanup_merge(xdmerge_t *c)
{
int count = 0;
xdmerge_t *next_c;

/* were there conflicts? */
for (; c; c = next_c) {
if (c->mode == 0)
count++;
next_c = c->next;
free(c);
}
return count;
}

static int xdl_merge_cmp_lines(xdfenv_t *xe1, int i1, xdfenv_t *xe2, int i2,
int line_count, long flags)
{
int i;
xrecord_t **rec1 = xe1->xdf2.recs + i1;
xrecord_t **rec2 = xe2->xdf2.recs + i2;

for (i = 0; i < line_count; i++) {
int result = xdl_recmatch(rec1[i]->ptr, rec1[i]->size,
rec2[i]->ptr, rec2[i]->size, flags);
if (!result)
return -1;
}
return 0;
}

static int xdl_recs_copy(xdfenv_t *xe, int i, int count, int add_nl, char *dest)
{
xrecord_t **recs = xe->xdf2.recs + i;
int size = 0;

if (count < 1)
return 0;

for (i = 0; i < count; size += recs[i++]->size)
if (dest)
memcpy(dest + size, recs[i]->ptr, recs[i]->size);
if (add_nl) {
i = recs[count - 1]->size;
if (i == 0 || recs[count - 1]->ptr[i - 1] != '\n') {
if (dest)
dest[size] = '\n';
size++;
}
}
return size;
}

static int xdl_fill_merge_buffer(xdfenv_t *xe1, const char *name1,
xdfenv_t *xe2, const char *name2, xdmerge_t *m, char *dest)
{
const int marker_size = 7;
int marker1_size = (name1 ? strlen(name1) + 1 : 0);
int marker2_size = (name2 ? strlen(name2) + 1 : 0);
int conflict_marker_size = 3 * (marker_size + 1)
+ marker1_size + marker2_size;
int size, i1, j;

for (size = i1 = 0; m; m = m->next) {
if (m->mode == 0) {
size += xdl_recs_copy(xe1, i1, m->i1 - i1, 0,
dest ? dest + size : NULL);
if (dest) {
for (j = 0; j < marker_size; j++)
dest[size++] = '<';
if (marker1_size) {
dest[size] = ' ';
memcpy(dest + size + 1, name1,
marker1_size - 1);
size += marker1_size;
}
dest[size++] = '\n';
} else
size += conflict_marker_size;
size += xdl_recs_copy(xe1, m->i1, m->chg1, 1,
dest ? dest + size : NULL);
if (dest) {
for (j = 0; j < marker_size; j++)
dest[size++] = '=';
dest[size++] = '\n';
}
size += xdl_recs_copy(xe2, m->i2, m->chg2, 1,
dest ? dest + size : NULL);
if (dest) {
for (j = 0; j < marker_size; j++)
dest[size++] = '>';
if (marker2_size) {
dest[size] = ' ';
memcpy(dest + size + 1, name2,
marker2_size - 1);
size += marker2_size;
}
dest[size++] = '\n';
}
} else if (m->mode == 1)
size += xdl_recs_copy(xe1, i1, m->i1 + m->chg1 - i1, 0,
dest ? dest + size : NULL);
else if (m->mode == 2)
size += xdl_recs_copy(xe2, m->i2 - m->i1 + i1,
m->i1 + m->chg2 - i1, 0,
dest ? dest + size : NULL);
i1 = m->i1 + m->chg1;
}
size += xdl_recs_copy(xe1, i1, xe1->xdf2.nrec - i1, 0,
dest ? dest + size : NULL);
return size;
}

/*
* Sometimes, changes are not quite identical, but differ in only a few
* lines. Try hard to show only these few lines as conflicting.
*/
static int xdl_refine_conflicts(xdfenv_t *xe1, xdfenv_t *xe2, xdmerge_t *m,
xpparam_t const *xpp)
{
for (; m; m = m->next) {
mmfile_t t1, t2;
xdfenv_t xe;
xdchange_t *xscr, *x;
int i1 = m->i1, i2 = m->i2;

/* let's handle just the conflicts */
if (m->mode)
continue;

/*
* This probably does not work outside git, since
* we have a very simple mmfile structure.
*/
t1.ptr = (char *)xe1->xdf2.recs[m->i1]->ptr;
t1.size = xe1->xdf2.recs[m->i1 + m->chg1 - 1]->ptr
+ xe1->xdf2.recs[m->i1 + m->chg1 - 1]->size - t1.ptr;
t2.ptr = (char *)xe2->xdf2.recs[m->i2]->ptr;
t2.size = xe2->xdf2.recs[m->i2 + m->chg2 - 1]->ptr
+ xe2->xdf2.recs[m->i2 + m->chg2 - 1]->size - t2.ptr;
if (xdl_do_diff(&t1, &t2, xpp, &xe) < 0)
return -1;
if (xdl_change_compact(&xe.xdf1, &xe.xdf2, xpp->flags) < 0 ||
xdl_change_compact(&xe.xdf2, &xe.xdf1, xpp->flags) < 0 ||
xdl_build_script(&xe, &xscr) < 0) {
xdl_free_env(&xe);
return -1;
}
if (!xscr) {
/* If this happens, it's a bug. */
xdl_free_env(&xe);
return -2;
}
x = xscr;
m->i1 = xscr->i1 + i1;
m->chg1 = xscr->chg1;
m->i2 = xscr->i2 + i2;
m->chg2 = xscr->chg2;
while (xscr->next) {
xdmerge_t *m2 = xdl_malloc(sizeof(xdmerge_t));
if (!m2) {
xdl_free_env(&xe);
xdl_free_script(x);
return -1;
}
xscr = xscr->next;
m2->next = m->next;
m->next = m2;
m = m2;
m->mode = 0;
m->i1 = xscr->i1 + i1;
m->chg1 = xscr->chg1;
m->i2 = xscr->i2 + i2;
m->chg2 = xscr->chg2;
}
xdl_free_env(&xe);
xdl_free_script(x);
}
return 0;
}

/*
* level == 0: mark all overlapping changes as conflict
* level == 1: mark overlapping changes as conflict only if not identical
* level == 2: analyze non-identical changes for minimal conflict set
*
* returns < 0 on error, == 0 for no conflicts, else number of conflicts
*/
static int xdl_do_merge(xdfenv_t *xe1, xdchange_t *xscr1, const char *name1,
xdfenv_t *xe2, xdchange_t *xscr2, const char *name2,
int level, xpparam_t const *xpp, mmbuffer_t *result) {
xdmerge_t *changes, *c;
int i1, i2, chg1, chg2;

c = changes = NULL;

while (xscr1 && xscr2) {
if (!changes)
changes = c;
if (xscr1->i1 + xscr1->chg1 < xscr2->i1) {
i1 = xscr1->i2;
i2 = xscr2->i2 - xscr2->i1 + xscr1->i1;
chg1 = xscr1->chg2;
chg2 = xscr1->chg1;
if (xdl_append_merge(&c, 1, i1, chg1, i2, chg2)) {
xdl_cleanup_merge(changes);
return -1;
}
xscr1 = xscr1->next;
continue;
}
if (xscr2->i1 + xscr2->chg1 < xscr1->i1) {
i1 = xscr1->i2 - xscr1->i1 + xscr2->i1;
i2 = xscr2->i2;
chg1 = xscr2->chg1;
chg2 = xscr2->chg2;
if (xdl_append_merge(&c, 2, i1, chg1, i2, chg2)) {
xdl_cleanup_merge(changes);
return -1;
}
xscr2 = xscr2->next;
continue;
}
if (level < 1 || xscr1->i1 != xscr2->i1 ||
xscr1->chg1 != xscr2->chg1 ||
xscr1->chg2 != xscr2->chg2 ||
xdl_merge_cmp_lines(xe1, xscr1->i2,
xe2, xscr2->i2,
xscr1->chg2, xpp->flags)) {
/* conflict */
int off = xscr1->i1 - xscr2->i1;
int ffo = off + xscr1->chg1 - xscr2->chg1;

i1 = xscr1->i2;
i2 = xscr2->i2;
if (off > 0)
i1 -= off;
else
i2 += off;
chg1 = xscr1->i2 + xscr1->chg2 - i1;
chg2 = xscr2->i2 + xscr2->chg2 - i2;
if (ffo > 0)
chg2 += ffo;
else
chg1 -= ffo;
if (xdl_append_merge(&c, 0, i1, chg1, i2, chg2)) {
xdl_cleanup_merge(changes);
return -1;
}
}

i1 = xscr1->i1 + xscr1->chg1;
i2 = xscr2->i1 + xscr2->chg1;

if (i1 >= i2)
xscr2 = xscr2->next;
if (i2 >= i1)
xscr1 = xscr1->next;
}
while (xscr1) {
if (!changes)
changes = c;
i1 = xscr1->i2;
i2 = xscr1->i1 + xe2->xdf2.nrec - xe2->xdf1.nrec;
chg1 = xscr1->chg2;
chg2 = xscr1->chg1;
if (xdl_append_merge(&c, 1, i1, chg1, i2, chg2)) {
xdl_cleanup_merge(changes);
return -1;
}
xscr1 = xscr1->next;
}
while (xscr2) {
if (!changes)
changes = c;
i1 = xscr2->i1 + xe1->xdf2.nrec - xe1->xdf1.nrec;
i2 = xscr2->i2;
chg1 = xscr2->chg1;
chg2 = xscr2->chg2;
if (xdl_append_merge(&c, 2, i1, chg1, i2, chg2)) {
xdl_cleanup_merge(changes);
return -1;
}
xscr2 = xscr2->next;
}
if (!changes)
changes = c;
/* refine conflicts */
if (level > 1 && xdl_refine_conflicts(xe1, xe2, changes, xpp) < 0) {
xdl_cleanup_merge(changes);
return -1;
}
/* output */
if (result) {
int size = xdl_fill_merge_buffer(xe1, name1, xe2, name2,
changes, NULL);
result->ptr = xdl_malloc(size);
if (!result->ptr) {
xdl_cleanup_merge(changes);
return -1;
}
result->size = size;
xdl_fill_merge_buffer(xe1, name1, xe2, name2, changes,
result->ptr);
}
return xdl_cleanup_merge(changes);
}

int xdl_merge(mmfile_t *orig, mmfile_t *mf1, const char *name1,
mmfile_t *mf2, const char *name2,
xpparam_t const *xpp, int level, mmbuffer_t *result) {
xdchange_t *xscr1, *xscr2;
xdfenv_t xe1, xe2;
int status;

result->ptr = NULL;
result->size = 0;

if (xdl_do_diff(orig, mf1, xpp, &xe1) < 0 ||
xdl_do_diff(orig, mf2, xpp, &xe2) < 0) {
return -1;
}
if (xdl_change_compact(&xe1.xdf1, &xe1.xdf2, xpp->flags) < 0 ||
xdl_change_compact(&xe1.xdf2, &xe1.xdf1, xpp->flags) < 0 ||
xdl_build_script(&xe1, &xscr1) < 0) {
xdl_free_env(&xe1);
return -1;
}
if (xdl_change_compact(&xe2.xdf1, &xe2.xdf2, xpp->flags) < 0 ||
xdl_change_compact(&xe2.xdf2, &xe2.xdf1, xpp->flags) < 0 ||
xdl_build_script(&xe2, &xscr2) < 0) {
xdl_free_env(&xe2);
return -1;
}
status = 0;
if (xscr1 || xscr2) {
if (!xscr1) {
result->ptr = xdl_malloc(mf2->size);
memcpy(result->ptr, mf2->ptr, mf2->size);
result->size = mf2->size;
} else if (!xscr2) {
result->ptr = xdl_malloc(mf1->size);
memcpy(result->ptr, mf1->ptr, mf1->size);
result->size = mf1->size;
} else {
status = xdl_do_merge(&xe1, xscr1, name1,
&xe2, xscr2, name2,
level, xpp, result);
}
xdl_free_script(xscr1);
xdl_free_script(xscr2);
}
xdl_free_env(&xe1);
xdl_free_env(&xe2);

return status;
}