git/merge-recursive.c
Junio C Hamano fadd069d03 merge-recursive: give less scary messages when merge did not start
When unpack_trees() three-way merge logic is called from merge-recursive
and finds that local changes are going to be clobbered, its plumbing level
messages were given as errors first, and then the merge driver added even
more scary message "fatal: merging of trees <a long object name> and
<another long object name> failed".

This is most often encountered by new CVS/SVN migrants who are used to
start a merge from a dirty work tree.  The saddest part is that the merge
refused to run to prevent _any_ damage from being done to your work tree
when these messages are given, but the messages look a lot more scarier
than the conflicted case where the user needs to resolve them.

Replace the plumbing level messages so that they talk about what it is
protecting the user from, and end the messages with "Aborting." so that it
becomes clear that the command did not do any harm.

The final "merging of trees failed" message is superfluous, unless you are
interested in debugging the merge-recursive itself.  Squelch the current
die() message by default, but allow it to help people who debug git with
verbosity level 4 or greater.

Unless there is some bug, an inner merge that does not touch working tree
should not trigger any such error, so emit the current die() message when
we see an error return from it while running the inner merge, too.  It
would also help people who debug git.

We could later add instructions on how to recover (i.e. "stash changes
away or commit on a side branch and retry") instead of the silent
exit(128) I have in this patch, and then use Peff's advice.* mechanism to
squelch it (e.g. "advice.mergeindirtytree"), but they are separate topics.

Tested-by: Nanako Shiraishi <nanako3@lavabit.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-08 14:46:36 -07:00

1430 lines
38 KiB
C

/*
* Recursive Merge algorithm stolen from git-merge-recursive.py by
* Fredrik Kuivinen.
* The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
*/
#include "cache.h"
#include "cache-tree.h"
#include "commit.h"
#include "blob.h"
#include "builtin.h"
#include "tree-walk.h"
#include "diff.h"
#include "diffcore.h"
#include "tag.h"
#include "unpack-trees.h"
#include "string-list.h"
#include "xdiff-interface.h"
#include "ll-merge.h"
#include "attr.h"
#include "merge-recursive.h"
#include "dir.h"
static struct tree *shift_tree_object(struct tree *one, struct tree *two)
{
unsigned char shifted[20];
/*
* NEEDSWORK: this limits the recursion depth to hardcoded
* value '2' to avoid excessive overhead.
*/
shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
if (!hashcmp(two->object.sha1, shifted))
return two;
return lookup_tree(shifted);
}
/*
* A virtual commit has (const char *)commit->util set to the name.
*/
static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
{
struct commit *commit = xcalloc(1, sizeof(struct commit));
commit->tree = tree;
commit->util = (void*)comment;
/* avoid warnings */
commit->object.parsed = 1;
return commit;
}
/*
* Since we use get_tree_entry(), which does not put the read object into
* the object pool, we cannot rely on a == b.
*/
static int sha_eq(const unsigned char *a, const unsigned char *b)
{
if (!a && !b)
return 2;
return a && b && hashcmp(a, b) == 0;
}
/*
* Since we want to write the index eventually, we cannot reuse the index
* for these (temporary) data.
*/
struct stage_data
{
struct
{
unsigned mode;
unsigned char sha[20];
} stages[4];
unsigned processed:1;
};
static int show(struct merge_options *o, int v)
{
return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
}
static void flush_output(struct merge_options *o)
{
if (o->obuf.len) {
fputs(o->obuf.buf, stdout);
strbuf_reset(&o->obuf);
}
}
static void output(struct merge_options *o, int v, const char *fmt, ...)
{
int len;
va_list ap;
if (!show(o, v))
return;
strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
va_start(ap, fmt);
len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
va_end(ap);
if (len < 0)
len = 0;
if (len >= strbuf_avail(&o->obuf)) {
strbuf_grow(&o->obuf, len + 2);
va_start(ap, fmt);
len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
va_end(ap);
if (len >= strbuf_avail(&o->obuf)) {
die("this should not happen, your snprintf is broken");
}
}
strbuf_setlen(&o->obuf, o->obuf.len + len);
strbuf_add(&o->obuf, "\n", 1);
if (!o->buffer_output)
flush_output(o);
}
static void output_commit_title(struct merge_options *o, struct commit *commit)
{
int i;
flush_output(o);
for (i = o->call_depth; i--;)
fputs(" ", stdout);
if (commit->util)
printf("virtual %s\n", (char *)commit->util);
else {
printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
if (parse_commit(commit) != 0)
printf("(bad commit)\n");
else {
const char *s;
int len;
for (s = commit->buffer; *s; s++)
if (*s == '\n' && s[1] == '\n') {
s += 2;
break;
}
for (len = 0; s[len] && '\n' != s[len]; len++)
; /* do nothing */
printf("%.*s\n", len, s);
}
}
}
static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
const char *path, int stage, int refresh, int options)
{
struct cache_entry *ce;
ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
if (!ce)
return error("addinfo_cache failed for path '%s'", path);
return add_cache_entry(ce, options);
}
static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
{
parse_tree(tree);
init_tree_desc(desc, tree->buffer, tree->size);
}
static int git_merge_trees(int index_only,
struct tree *common,
struct tree *head,
struct tree *merge)
{
int rc;
struct tree_desc t[3];
struct unpack_trees_options opts;
static const struct unpack_trees_error_msgs msgs = {
/* would_overwrite */
"Your local changes to '%s' would be overwritten by merge. Aborting.",
/* not_uptodate_file */
"Your local changes to '%s' would be overwritten by merge. Aborting.",
/* not_uptodate_dir */
"Updating '%s' would lose untracked files in it. Aborting.",
/* would_lose_untracked */
"Untracked working tree file '%s' would be %s by merge. Aborting",
/* bind_overlap -- will not happen here */
NULL,
};
memset(&opts, 0, sizeof(opts));
if (index_only)
opts.index_only = 1;
else
opts.update = 1;
opts.merge = 1;
opts.head_idx = 2;
opts.fn = threeway_merge;
opts.src_index = &the_index;
opts.dst_index = &the_index;
opts.msgs = msgs;
init_tree_desc_from_tree(t+0, common);
init_tree_desc_from_tree(t+1, head);
init_tree_desc_from_tree(t+2, merge);
rc = unpack_trees(3, t, &opts);
cache_tree_free(&active_cache_tree);
return rc;
}
struct tree *write_tree_from_memory(struct merge_options *o)
{
struct tree *result = NULL;
if (unmerged_cache()) {
int i;
output(o, 0, "There are unmerged index entries:");
for (i = 0; i < active_nr; i++) {
struct cache_entry *ce = active_cache[i];
if (ce_stage(ce))
output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
}
return NULL;
}
if (!active_cache_tree)
active_cache_tree = cache_tree();
if (!cache_tree_fully_valid(active_cache_tree) &&
cache_tree_update(active_cache_tree,
active_cache, active_nr, 0, 0) < 0)
die("error building trees");
result = lookup_tree(active_cache_tree->sha1);
return result;
}
static int save_files_dirs(const unsigned char *sha1,
const char *base, int baselen, const char *path,
unsigned int mode, int stage, void *context)
{
int len = strlen(path);
char *newpath = xmalloc(baselen + len + 1);
struct merge_options *o = context;
memcpy(newpath, base, baselen);
memcpy(newpath + baselen, path, len);
newpath[baselen + len] = '\0';
if (S_ISDIR(mode))
string_list_insert(newpath, &o->current_directory_set);
else
string_list_insert(newpath, &o->current_file_set);
free(newpath);
return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
}
static int get_files_dirs(struct merge_options *o, struct tree *tree)
{
int n;
if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
return 0;
n = o->current_file_set.nr + o->current_directory_set.nr;
return n;
}
/*
* Returns an index_entry instance which doesn't have to correspond to
* a real cache entry in Git's index.
*/
static struct stage_data *insert_stage_data(const char *path,
struct tree *o, struct tree *a, struct tree *b,
struct string_list *entries)
{
struct string_list_item *item;
struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
get_tree_entry(o->object.sha1, path,
e->stages[1].sha, &e->stages[1].mode);
get_tree_entry(a->object.sha1, path,
e->stages[2].sha, &e->stages[2].mode);
get_tree_entry(b->object.sha1, path,
e->stages[3].sha, &e->stages[3].mode);
item = string_list_insert(path, entries);
item->util = e;
return e;
}
/*
* Create a dictionary mapping file names to stage_data objects. The
* dictionary contains one entry for every path with a non-zero stage entry.
*/
static struct string_list *get_unmerged(void)
{
struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
int i;
unmerged->strdup_strings = 1;
for (i = 0; i < active_nr; i++) {
struct string_list_item *item;
struct stage_data *e;
struct cache_entry *ce = active_cache[i];
if (!ce_stage(ce))
continue;
item = string_list_lookup(ce->name, unmerged);
if (!item) {
item = string_list_insert(ce->name, unmerged);
item->util = xcalloc(1, sizeof(struct stage_data));
}
e = item->util;
e->stages[ce_stage(ce)].mode = ce->ce_mode;
hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
}
return unmerged;
}
struct rename
{
struct diff_filepair *pair;
struct stage_data *src_entry;
struct stage_data *dst_entry;
unsigned processed:1;
};
/*
* Get information of all renames which occurred between 'o_tree' and
* 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
* 'b_tree') to be able to associate the correct cache entries with
* the rename information. 'tree' is always equal to either a_tree or b_tree.
*/
static struct string_list *get_renames(struct merge_options *o,
struct tree *tree,
struct tree *o_tree,
struct tree *a_tree,
struct tree *b_tree,
struct string_list *entries)
{
int i;
struct string_list *renames;
struct diff_options opts;
renames = xcalloc(1, sizeof(struct string_list));
diff_setup(&opts);
DIFF_OPT_SET(&opts, RECURSIVE);
opts.detect_rename = DIFF_DETECT_RENAME;
opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
o->diff_rename_limit >= 0 ? o->diff_rename_limit :
500;
opts.warn_on_too_large_rename = 1;
opts.output_format = DIFF_FORMAT_NO_OUTPUT;
if (diff_setup_done(&opts) < 0)
die("diff setup failed");
diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
diffcore_std(&opts);
for (i = 0; i < diff_queued_diff.nr; ++i) {
struct string_list_item *item;
struct rename *re;
struct diff_filepair *pair = diff_queued_diff.queue[i];
if (pair->status != 'R') {
diff_free_filepair(pair);
continue;
}
re = xmalloc(sizeof(*re));
re->processed = 0;
re->pair = pair;
item = string_list_lookup(re->pair->one->path, entries);
if (!item)
re->src_entry = insert_stage_data(re->pair->one->path,
o_tree, a_tree, b_tree, entries);
else
re->src_entry = item->util;
item = string_list_lookup(re->pair->two->path, entries);
if (!item)
re->dst_entry = insert_stage_data(re->pair->two->path,
o_tree, a_tree, b_tree, entries);
else
re->dst_entry = item->util;
item = string_list_insert(pair->one->path, renames);
item->util = re;
}
opts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_queued_diff.nr = 0;
diff_flush(&opts);
return renames;
}
static int update_stages(const char *path, struct diff_filespec *o,
struct diff_filespec *a, struct diff_filespec *b,
int clear)
{
int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
if (clear)
if (remove_file_from_cache(path))
return -1;
if (o)
if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
return -1;
if (a)
if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
return -1;
if (b)
if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
return -1;
return 0;
}
static int remove_file(struct merge_options *o, int clean,
const char *path, int no_wd)
{
int update_cache = o->call_depth || clean;
int update_working_directory = !o->call_depth && !no_wd;
if (update_cache) {
if (remove_file_from_cache(path))
return -1;
}
if (update_working_directory) {
if (remove_path(path) && errno != ENOENT)
return -1;
}
return 0;
}
static char *unique_path(struct merge_options *o, const char *path, const char *branch)
{
char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
int suffix = 0;
struct stat st;
char *p = newpath + strlen(path);
strcpy(newpath, path);
*(p++) = '~';
strcpy(p, branch);
for (; *p; ++p)
if ('/' == *p)
*p = '_';
while (string_list_has_string(&o->current_file_set, newpath) ||
string_list_has_string(&o->current_directory_set, newpath) ||
lstat(newpath, &st) == 0)
sprintf(p, "_%d", suffix++);
string_list_insert(newpath, &o->current_file_set);
return newpath;
}
static void flush_buffer(int fd, const char *buf, unsigned long size)
{
while (size > 0) {
long ret = write_in_full(fd, buf, size);
if (ret < 0) {
/* Ignore epipe */
if (errno == EPIPE)
break;
die_errno("merge-recursive");
} else if (!ret) {
die("merge-recursive: disk full?");
}
size -= ret;
buf += ret;
}
}
static int would_lose_untracked(const char *path)
{
int pos = cache_name_pos(path, strlen(path));
if (pos < 0)
pos = -1 - pos;
while (pos < active_nr &&
!strcmp(path, active_cache[pos]->name)) {
/*
* If stage #0, it is definitely tracked.
* If it has stage #2 then it was tracked
* before this merge started. All other
* cases the path was not tracked.
*/
switch (ce_stage(active_cache[pos])) {
case 0:
case 2:
return 0;
}
pos++;
}
return file_exists(path);
}
static int make_room_for_path(const char *path)
{
int status;
const char *msg = "failed to create path '%s'%s";
status = safe_create_leading_directories_const(path);
if (status) {
if (status == -3) {
/* something else exists */
error(msg, path, ": perhaps a D/F conflict?");
return -1;
}
die(msg, path, "");
}
/*
* Do not unlink a file in the work tree if we are not
* tracking it.
*/
if (would_lose_untracked(path))
return error("refusing to lose untracked file at '%s'",
path);
/* Successful unlink is good.. */
if (!unlink(path))
return 0;
/* .. and so is no existing file */
if (errno == ENOENT)
return 0;
/* .. but not some other error (who really cares what?) */
return error(msg, path, ": perhaps a D/F conflict?");
}
static void update_file_flags(struct merge_options *o,
const unsigned char *sha,
unsigned mode,
const char *path,
int update_cache,
int update_wd)
{
if (o->call_depth)
update_wd = 0;
if (update_wd) {
enum object_type type;
void *buf;
unsigned long size;
if (S_ISGITLINK(mode))
/*
* We may later decide to recursively descend into
* the submodule directory and update its index
* and/or work tree, but we do not do that now.
*/
goto update_index;
buf = read_sha1_file(sha, &type, &size);
if (!buf)
die("cannot read object %s '%s'", sha1_to_hex(sha), path);
if (type != OBJ_BLOB)
die("blob expected for %s '%s'", sha1_to_hex(sha), path);
if (S_ISREG(mode)) {
struct strbuf strbuf = STRBUF_INIT;
if (convert_to_working_tree(path, buf, size, &strbuf)) {
free(buf);
size = strbuf.len;
buf = strbuf_detach(&strbuf, NULL);
}
}
if (make_room_for_path(path) < 0) {
update_wd = 0;
free(buf);
goto update_index;
}
if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
int fd;
if (mode & 0100)
mode = 0777;
else
mode = 0666;
fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
if (fd < 0)
die_errno("failed to open '%s'", path);
flush_buffer(fd, buf, size);
close(fd);
} else if (S_ISLNK(mode)) {
char *lnk = xmemdupz(buf, size);
safe_create_leading_directories_const(path);
unlink(path);
if (symlink(lnk, path))
die_errno("failed to symlink '%s'", path);
free(lnk);
} else
die("do not know what to do with %06o %s '%s'",
mode, sha1_to_hex(sha), path);
free(buf);
}
update_index:
if (update_cache)
add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
}
static void update_file(struct merge_options *o,
int clean,
const unsigned char *sha,
unsigned mode,
const char *path)
{
update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
}
/* Low level file merging, update and removal */
struct merge_file_info
{
unsigned char sha[20];
unsigned mode;
unsigned clean:1,
merge:1;
};
static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
{
unsigned long size;
enum object_type type;
if (!hashcmp(sha1, null_sha1)) {
mm->ptr = xstrdup("");
mm->size = 0;
return;
}
mm->ptr = read_sha1_file(sha1, &type, &size);
if (!mm->ptr || type != OBJ_BLOB)
die("unable to read blob object %s", sha1_to_hex(sha1));
mm->size = size;
}
static int merge_3way(struct merge_options *o,
mmbuffer_t *result_buf,
struct diff_filespec *one,
struct diff_filespec *a,
struct diff_filespec *b,
const char *branch1,
const char *branch2)
{
mmfile_t orig, src1, src2;
char *name1, *name2;
int merge_status;
if (strcmp(a->path, b->path)) {
name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
} else {
name1 = xstrdup(mkpath("%s", branch1));
name2 = xstrdup(mkpath("%s", branch2));
}
fill_mm(one->sha1, &orig);
fill_mm(a->sha1, &src1);
fill_mm(b->sha1, &src2);
merge_status = ll_merge(result_buf, a->path, &orig,
&src1, name1, &src2, name2,
o->call_depth);
free(name1);
free(name2);
free(orig.ptr);
free(src1.ptr);
free(src2.ptr);
return merge_status;
}
static struct merge_file_info merge_file(struct merge_options *o,
struct diff_filespec *one,
struct diff_filespec *a,
struct diff_filespec *b,
const char *branch1,
const char *branch2)
{
struct merge_file_info result;
result.merge = 0;
result.clean = 1;
if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
result.clean = 0;
if (S_ISREG(a->mode)) {
result.mode = a->mode;
hashcpy(result.sha, a->sha1);
} else {
result.mode = b->mode;
hashcpy(result.sha, b->sha1);
}
} else {
if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
result.merge = 1;
/*
* Merge modes
*/
if (a->mode == b->mode || a->mode == one->mode)
result.mode = b->mode;
else {
result.mode = a->mode;
if (b->mode != one->mode) {
result.clean = 0;
result.merge = 1;
}
}
if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
hashcpy(result.sha, b->sha1);
else if (sha_eq(b->sha1, one->sha1))
hashcpy(result.sha, a->sha1);
else if (S_ISREG(a->mode)) {
mmbuffer_t result_buf;
int merge_status;
merge_status = merge_3way(o, &result_buf, one, a, b,
branch1, branch2);
if ((merge_status < 0) || !result_buf.ptr)
die("Failed to execute internal merge");
if (write_sha1_file(result_buf.ptr, result_buf.size,
blob_type, result.sha))
die("Unable to add %s to database",
a->path);
free(result_buf.ptr);
result.clean = (merge_status == 0);
} else if (S_ISGITLINK(a->mode)) {
result.clean = 0;
hashcpy(result.sha, a->sha1);
} else if (S_ISLNK(a->mode)) {
hashcpy(result.sha, a->sha1);
if (!sha_eq(a->sha1, b->sha1))
result.clean = 0;
} else {
die("unsupported object type in the tree");
}
}
return result;
}
static void conflict_rename_rename(struct merge_options *o,
struct rename *ren1,
const char *branch1,
struct rename *ren2,
const char *branch2)
{
char *del[2];
int delp = 0;
const char *ren1_dst = ren1->pair->two->path;
const char *ren2_dst = ren2->pair->two->path;
const char *dst_name1 = ren1_dst;
const char *dst_name2 = ren2_dst;
if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
output(o, 1, "%s is a directory in %s adding as %s instead",
ren1_dst, branch2, dst_name1);
remove_file(o, 0, ren1_dst, 0);
}
if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
output(o, 1, "%s is a directory in %s adding as %s instead",
ren2_dst, branch1, dst_name2);
remove_file(o, 0, ren2_dst, 0);
}
if (o->call_depth) {
remove_file_from_cache(dst_name1);
remove_file_from_cache(dst_name2);
/*
* Uncomment to leave the conflicting names in the resulting tree
*
* update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
* update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
*/
} else {
update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
}
while (delp--)
free(del[delp]);
}
static void conflict_rename_dir(struct merge_options *o,
struct rename *ren1,
const char *branch1)
{
char *new_path = unique_path(o, ren1->pair->two->path, branch1);
output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
remove_file(o, 0, ren1->pair->two->path, 0);
update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
free(new_path);
}
static void conflict_rename_rename_2(struct merge_options *o,
struct rename *ren1,
const char *branch1,
struct rename *ren2,
const char *branch2)
{
char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
output(o, 1, "Renaming %s to %s and %s to %s instead",
ren1->pair->one->path, new_path1,
ren2->pair->one->path, new_path2);
remove_file(o, 0, ren1->pair->two->path, 0);
update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
free(new_path2);
free(new_path1);
}
static int process_renames(struct merge_options *o,
struct string_list *a_renames,
struct string_list *b_renames)
{
int clean_merge = 1, i, j;
struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
const struct rename *sre;
for (i = 0; i < a_renames->nr; i++) {
sre = a_renames->items[i].util;
string_list_insert(sre->pair->two->path, &a_by_dst)->util
= sre->dst_entry;
}
for (i = 0; i < b_renames->nr; i++) {
sre = b_renames->items[i].util;
string_list_insert(sre->pair->two->path, &b_by_dst)->util
= sre->dst_entry;
}
for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
char *src;
struct string_list *renames1, *renames2Dst;
struct rename *ren1 = NULL, *ren2 = NULL;
const char *branch1, *branch2;
const char *ren1_src, *ren1_dst;
if (i >= a_renames->nr) {
ren2 = b_renames->items[j++].util;
} else if (j >= b_renames->nr) {
ren1 = a_renames->items[i++].util;
} else {
int compare = strcmp(a_renames->items[i].string,
b_renames->items[j].string);
if (compare <= 0)
ren1 = a_renames->items[i++].util;
if (compare >= 0)
ren2 = b_renames->items[j++].util;
}
/* TODO: refactor, so that 1/2 are not needed */
if (ren1) {
renames1 = a_renames;
renames2Dst = &b_by_dst;
branch1 = o->branch1;
branch2 = o->branch2;
} else {
struct rename *tmp;
renames1 = b_renames;
renames2Dst = &a_by_dst;
branch1 = o->branch2;
branch2 = o->branch1;
tmp = ren2;
ren2 = ren1;
ren1 = tmp;
}
src = ren1->pair->one->path;
ren1->dst_entry->processed = 1;
ren1->src_entry->processed = 1;
if (ren1->processed)
continue;
ren1->processed = 1;
ren1_src = ren1->pair->one->path;
ren1_dst = ren1->pair->two->path;
if (ren2) {
const char *ren2_src = ren2->pair->one->path;
const char *ren2_dst = ren2->pair->two->path;
/* Renamed in 1 and renamed in 2 */
if (strcmp(ren1_src, ren2_src) != 0)
die("ren1.src != ren2.src");
ren2->dst_entry->processed = 1;
ren2->processed = 1;
if (strcmp(ren1_dst, ren2_dst) != 0) {
clean_merge = 0;
output(o, 1, "CONFLICT (rename/rename): "
"Rename \"%s\"->\"%s\" in branch \"%s\" "
"rename \"%s\"->\"%s\" in \"%s\"%s",
src, ren1_dst, branch1,
src, ren2_dst, branch2,
o->call_depth ? " (left unresolved)": "");
if (o->call_depth) {
remove_file_from_cache(src);
update_file(o, 0, ren1->pair->one->sha1,
ren1->pair->one->mode, src);
}
conflict_rename_rename(o, ren1, branch1, ren2, branch2);
} else {
struct merge_file_info mfi;
remove_file(o, 1, ren1_src, 1);
mfi = merge_file(o,
ren1->pair->one,
ren1->pair->two,
ren2->pair->two,
branch1,
branch2);
if (mfi.merge || !mfi.clean)
output(o, 1, "Renaming %s->%s", src, ren1_dst);
if (mfi.merge)
output(o, 2, "Auto-merging %s", ren1_dst);
if (!mfi.clean) {
output(o, 1, "CONFLICT (content): merge conflict in %s",
ren1_dst);
clean_merge = 0;
if (!o->call_depth)
update_stages(ren1_dst,
ren1->pair->one,
ren1->pair->two,
ren2->pair->two,
1 /* clear */);
}
update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
}
} else {
/* Renamed in 1, maybe changed in 2 */
struct string_list_item *item;
/* we only use sha1 and mode of these */
struct diff_filespec src_other, dst_other;
int try_merge, stage = a_renames == renames1 ? 3: 2;
remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
src_other.mode = ren1->src_entry->stages[stage].mode;
hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
dst_other.mode = ren1->dst_entry->stages[stage].mode;
try_merge = 0;
if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
clean_merge = 0;
output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
" directory %s added in %s",
ren1_src, ren1_dst, branch1,
ren1_dst, branch2);
conflict_rename_dir(o, ren1, branch1);
} else if (sha_eq(src_other.sha1, null_sha1)) {
clean_merge = 0;
output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
"and deleted in %s",
ren1_src, ren1_dst, branch1,
branch2);
update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
if (!o->call_depth)
update_stages(ren1_dst, NULL,
branch1 == o->branch1 ?
ren1->pair->two : NULL,
branch1 == o->branch1 ?
NULL : ren1->pair->two, 1);
} else if (!sha_eq(dst_other.sha1, null_sha1)) {
const char *new_path;
clean_merge = 0;
try_merge = 1;
output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
"%s added in %s",
ren1_src, ren1_dst, branch1,
ren1_dst, branch2);
if (o->call_depth) {
struct merge_file_info mfi;
struct diff_filespec one, a, b;
one.path = a.path = b.path =
(char *)ren1_dst;
hashcpy(one.sha1, null_sha1);
one.mode = 0;
hashcpy(a.sha1, ren1->pair->two->sha1);
a.mode = ren1->pair->two->mode;
hashcpy(b.sha1, dst_other.sha1);
b.mode = dst_other.mode;
mfi = merge_file(o, &one, &a, &b,
branch1,
branch2);
output(o, 1, "Adding merged %s", ren1_dst);
update_file(o, 0,
mfi.sha,
mfi.mode,
ren1_dst);
} else {
new_path = unique_path(o, ren1_dst, branch2);
output(o, 1, "Adding as %s instead", new_path);
update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
}
} else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
ren2 = item->util;
clean_merge = 0;
ren2->processed = 1;
output(o, 1, "CONFLICT (rename/rename): "
"Rename %s->%s in %s. "
"Rename %s->%s in %s",
ren1_src, ren1_dst, branch1,
ren2->pair->one->path, ren2->pair->two->path, branch2);
conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
} else
try_merge = 1;
if (try_merge) {
struct diff_filespec *one, *a, *b;
struct merge_file_info mfi;
src_other.path = (char *)ren1_src;
one = ren1->pair->one;
if (a_renames == renames1) {
a = ren1->pair->two;
b = &src_other;
} else {
b = ren1->pair->two;
a = &src_other;
}
mfi = merge_file(o, one, a, b,
o->branch1, o->branch2);
if (mfi.clean &&
sha_eq(mfi.sha, ren1->pair->two->sha1) &&
mfi.mode == ren1->pair->two->mode)
/*
* This messaged is part of
* t6022 test. If you change
* it update the test too.
*/
output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
else {
if (mfi.merge || !mfi.clean)
output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
if (mfi.merge)
output(o, 2, "Auto-merging %s", ren1_dst);
if (!mfi.clean) {
output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
ren1_dst);
clean_merge = 0;
if (!o->call_depth)
update_stages(ren1_dst,
one, a, b, 1);
}
update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
}
}
}
}
string_list_clear(&a_by_dst, 0);
string_list_clear(&b_by_dst, 0);
return clean_merge;
}
static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
{
return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
}
/* Per entry merge function */
static int process_entry(struct merge_options *o,
const char *path, struct stage_data *entry)
{
/*
printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
print_index_entry("\tpath: ", entry);
*/
int clean_merge = 1;
unsigned o_mode = entry->stages[1].mode;
unsigned a_mode = entry->stages[2].mode;
unsigned b_mode = entry->stages[3].mode;
unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
if (o_sha && (!a_sha || !b_sha)) {
/* Case A: Deleted in one */
if ((!a_sha && !b_sha) ||
(sha_eq(a_sha, o_sha) && !b_sha) ||
(!a_sha && sha_eq(b_sha, o_sha))) {
/* Deleted in both or deleted in one and
* unchanged in the other */
if (a_sha)
output(o, 2, "Removing %s", path);
/* do not touch working file if it did not exist */
remove_file(o, 1, path, !a_sha);
} else {
/* Deleted in one and changed in the other */
clean_merge = 0;
if (!a_sha) {
output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
"and modified in %s. Version %s of %s left in tree.",
path, o->branch1,
o->branch2, o->branch2, path);
update_file(o, 0, b_sha, b_mode, path);
} else {
output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
"and modified in %s. Version %s of %s left in tree.",
path, o->branch2,
o->branch1, o->branch1, path);
update_file(o, 0, a_sha, a_mode, path);
}
}
} else if ((!o_sha && a_sha && !b_sha) ||
(!o_sha && !a_sha && b_sha)) {
/* Case B: Added in one. */
const char *add_branch;
const char *other_branch;
unsigned mode;
const unsigned char *sha;
const char *conf;
if (a_sha) {
add_branch = o->branch1;
other_branch = o->branch2;
mode = a_mode;
sha = a_sha;
conf = "file/directory";
} else {
add_branch = o->branch2;
other_branch = o->branch1;
mode = b_mode;
sha = b_sha;
conf = "directory/file";
}
if (string_list_has_string(&o->current_directory_set, path)) {
const char *new_path = unique_path(o, path, add_branch);
clean_merge = 0;
output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
"Adding %s as %s",
conf, path, other_branch, path, new_path);
remove_file(o, 0, path, 0);
update_file(o, 0, sha, mode, new_path);
} else {
output(o, 2, "Adding %s", path);
update_file(o, 1, sha, mode, path);
}
} 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 one, a, b;
if (!o_sha) {
reason = "add/add";
o_sha = (unsigned char *)null_sha1;
}
output(o, 2, "Auto-merging %s", path);
one.path = a.path = b.path = (char *)path;
hashcpy(one.sha1, o_sha);
one.mode = o_mode;
hashcpy(a.sha1, a_sha);
a.mode = a_mode;
hashcpy(b.sha1, b_sha);
b.mode = b_mode;
mfi = merge_file(o, &one, &a, &b,
o->branch1, o->branch2);
clean_merge = mfi.clean;
if (!mfi.clean) {
if (S_ISGITLINK(mfi.mode))
reason = "submodule";
output(o, 1, "CONFLICT (%s): Merge conflict in %s",
reason, path);
}
update_file(o, mfi.clean, mfi.sha, mfi.mode, path);
} else if (!o_sha && !a_sha && !b_sha) {
/*
* this entry was deleted altogether. a_mode == 0 means
* we had that path and want to actively remove it.
*/
remove_file(o, 1, path, !a_mode);
} else
die("Fatal merge failure, shouldn't happen.");
return clean_merge;
}
int merge_trees(struct merge_options *o,
struct tree *head,
struct tree *merge,
struct tree *common,
struct tree **result)
{
int code, clean;
if (o->subtree_merge) {
merge = shift_tree_object(head, merge);
common = shift_tree_object(head, common);
}
if (sha_eq(common->object.sha1, merge->object.sha1)) {
output(o, 0, "Already uptodate!");
*result = head;
return 1;
}
code = git_merge_trees(o->call_depth, common, head, merge);
if (code != 0) {
if (show(o, 4) || o->call_depth)
die("merging of trees %s and %s failed",
sha1_to_hex(head->object.sha1),
sha1_to_hex(merge->object.sha1));
else
exit(128);
}
if (unmerged_cache()) {
struct string_list *entries, *re_head, *re_merge;
int i;
string_list_clear(&o->current_file_set, 1);
string_list_clear(&o->current_directory_set, 1);
get_files_dirs(o, head);
get_files_dirs(o, merge);
entries = get_unmerged();
re_head = get_renames(o, head, common, head, merge, entries);
re_merge = get_renames(o, merge, common, head, merge, entries);
clean = process_renames(o, re_head, re_merge);
for (i = 0; i < entries->nr; i++) {
const char *path = entries->items[i].string;
struct stage_data *e = entries->items[i].util;
if (!e->processed
&& !process_entry(o, path, e))
clean = 0;
}
string_list_clear(re_merge, 0);
string_list_clear(re_head, 0);
string_list_clear(entries, 1);
}
else
clean = 1;
if (o->call_depth)
*result = write_tree_from_memory(o);
return clean;
}
static struct commit_list *reverse_commit_list(struct commit_list *list)
{
struct commit_list *next = NULL, *current, *backup;
for (current = list; current; current = backup) {
backup = current->next;
current->next = next;
next = current;
}
return next;
}
/*
* Merge the commits h1 and h2, return the resulting virtual
* commit object and a flag indicating the cleanness of the merge.
*/
int merge_recursive(struct merge_options *o,
struct commit *h1,
struct commit *h2,
struct commit_list *ca,
struct commit **result)
{
struct commit_list *iter;
struct commit *merged_common_ancestors;
struct tree *mrtree = mrtree;
int clean;
if (show(o, 4)) {
output(o, 4, "Merging:");
output_commit_title(o, h1);
output_commit_title(o, h2);
}
if (!ca) {
ca = get_merge_bases(h1, h2, 1);
ca = reverse_commit_list(ca);
}
if (show(o, 5)) {
output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
for (iter = ca; iter; iter = iter->next)
output_commit_title(o, iter->item);
}
merged_common_ancestors = pop_commit(&ca);
if (merged_common_ancestors == NULL) {
/* if there is no common ancestor, make an empty tree */
struct tree *tree = xcalloc(1, sizeof(struct tree));
tree->object.parsed = 1;
tree->object.type = OBJ_TREE;
pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
merged_common_ancestors = make_virtual_commit(tree, "ancestor");
}
for (iter = ca; iter; iter = iter->next) {
const char *saved_b1, *saved_b2;
o->call_depth++;
/*
* When the merge fails, the result contains files
* with conflict markers. The cleanness flag is
* ignored, it was never actually used, as result of
* merge_trees has always overwritten it: the committed
* "conflicts" were already resolved.
*/
discard_cache();
saved_b1 = o->branch1;
saved_b2 = o->branch2;
o->branch1 = "Temporary merge branch 1";
o->branch2 = "Temporary merge branch 2";
merge_recursive(o, merged_common_ancestors, iter->item,
NULL, &merged_common_ancestors);
o->branch1 = saved_b1;
o->branch2 = saved_b2;
o->call_depth--;
if (!merged_common_ancestors)
die("merge returned no commit");
}
discard_cache();
if (!o->call_depth)
read_cache();
clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
&mrtree);
if (o->call_depth) {
*result = make_virtual_commit(mrtree, "merged tree");
commit_list_insert(h1, &(*result)->parents);
commit_list_insert(h2, &(*result)->parents->next);
}
flush_output(o);
return clean;
}
static struct commit *get_ref(const unsigned char *sha1, const char *name)
{
struct object *object;
object = deref_tag(parse_object(sha1), name, strlen(name));
if (!object)
return NULL;
if (object->type == OBJ_TREE)
return make_virtual_commit((struct tree*)object, name);
if (object->type != OBJ_COMMIT)
return NULL;
if (parse_commit((struct commit *)object))
return NULL;
return (struct commit *)object;
}
int merge_recursive_generic(struct merge_options *o,
const unsigned char *head,
const unsigned char *merge,
int num_base_list,
const unsigned char **base_list,
struct commit **result)
{
int clean, index_fd;
struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
struct commit *head_commit = get_ref(head, o->branch1);
struct commit *next_commit = get_ref(merge, o->branch2);
struct commit_list *ca = NULL;
if (base_list) {
int i;
for (i = 0; i < num_base_list; ++i) {
struct commit *base;
if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
return error("Could not parse object '%s'",
sha1_to_hex(base_list[i]));
commit_list_insert(base, &ca);
}
}
index_fd = hold_locked_index(lock, 1);
clean = merge_recursive(o, head_commit, next_commit, ca,
result);
if (active_cache_changed &&
(write_cache(index_fd, active_cache, active_nr) ||
commit_locked_index(lock)))
return error("Unable to write index.");
return clean ? 0 : 1;
}
static int merge_recursive_config(const char *var, const char *value, void *cb)
{
struct merge_options *o = cb;
if (!strcasecmp(var, "merge.verbosity")) {
o->verbosity = git_config_int(var, value);
return 0;
}
if (!strcasecmp(var, "diff.renamelimit")) {
o->diff_rename_limit = git_config_int(var, value);
return 0;
}
if (!strcasecmp(var, "merge.renamelimit")) {
o->merge_rename_limit = git_config_int(var, value);
return 0;
}
return git_xmerge_config(var, value, cb);
}
void init_merge_options(struct merge_options *o)
{
memset(o, 0, sizeof(struct merge_options));
o->verbosity = 2;
o->buffer_output = 1;
o->diff_rename_limit = -1;
o->merge_rename_limit = -1;
git_config(merge_recursive_config, o);
if (getenv("GIT_MERGE_VERBOSITY"))
o->verbosity =
strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
if (o->verbosity >= 5)
o->buffer_output = 0;
strbuf_init(&o->obuf, 0);
memset(&o->current_file_set, 0, sizeof(struct string_list));
o->current_file_set.strdup_strings = 1;
memset(&o->current_directory_set, 0, sizeof(struct string_list));
o->current_directory_set.strdup_strings = 1;
}