Revision 3ba2e8653c88d220b0b22f35260477bb0afa7d7b authored by Johannes Sixt on 16 March 2011, 08:18:49 UTC, committed by Junio C Hamano on 17 March 2011, 21:54:11 UTC
'git stash create' must operate with a temporary index. For this purpose, it used 'cp -p' to create a copy. -p is needed to preserve the timestamp of the index file. Now Jakob Pfender reported a certain combination of a Linux NFS client, OpenBSD NFS server, and cp implementation where this operation failed. Luckily, the first operation in git-stash after copying the index is to call 'git read-tree'. Therefore, use --index-output instead of 'cp -p' to write the copy of the index. --index-output requires that the specified file is on the same volume as the source index, so that the lock file can be rename()d. For this reason, the name of the temporary index is constructed in a way different from the other temporary files. The code path of 'stash -p' also needs a temporary index, but we do not use the new name because it does not depend on the same precondition as --index-output. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 23a32ff
tree-diff.c
/*
* Helper functions for tree diff generation
*/
#include "cache.h"
#include "diff.h"
#include "diffcore.h"
#include "tree.h"
static char *malloc_base(const char *base, int baselen, const char *path, int pathlen)
{
char *newbase = xmalloc(baselen + pathlen + 2);
memcpy(newbase, base, baselen);
memcpy(newbase + baselen, path, pathlen);
memcpy(newbase + baselen + pathlen, "/", 2);
return newbase;
}
static char *malloc_fullname(const char *base, int baselen, const char *path, int pathlen)
{
char *fullname = xmalloc(baselen + pathlen + 1);
memcpy(fullname, base, baselen);
memcpy(fullname + baselen, path, pathlen);
fullname[baselen + pathlen] = 0;
return fullname;
}
static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
const char *base, int baselen);
static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt)
{
unsigned mode1, mode2;
const char *path1, *path2;
const unsigned char *sha1, *sha2;
int cmp, pathlen1, pathlen2;
char *fullname;
sha1 = tree_entry_extract(t1, &path1, &mode1);
sha2 = tree_entry_extract(t2, &path2, &mode2);
pathlen1 = tree_entry_len(path1, sha1);
pathlen2 = tree_entry_len(path2, sha2);
cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
if (cmp < 0) {
show_entry(opt, "-", t1, base, baselen);
return -1;
}
if (cmp > 0) {
show_entry(opt, "+", t2, base, baselen);
return 1;
}
if (!DIFF_OPT_TST(opt, FIND_COPIES_HARDER) && !hashcmp(sha1, sha2) && mode1 == mode2)
return 0;
/*
* If the filemode has changed to/from a directory from/to a regular
* file, we need to consider it a remove and an add.
*/
if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
show_entry(opt, "-", t1, base, baselen);
show_entry(opt, "+", t2, base, baselen);
return 0;
}
if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode1)) {
int retval;
char *newbase = malloc_base(base, baselen, path1, pathlen1);
if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
newbase[baselen + pathlen1] = 0;
opt->change(opt, mode1, mode2,
sha1, sha2, newbase, 0, 0);
newbase[baselen + pathlen1] = '/';
}
retval = diff_tree_sha1(sha1, sha2, newbase, opt);
free(newbase);
return retval;
}
fullname = malloc_fullname(base, baselen, path1, pathlen1);
opt->change(opt, mode1, mode2, sha1, sha2, fullname, 0, 0);
free(fullname);
return 0;
}
/*
* Is a tree entry interesting given the pathspec we have?
*
* Pre-condition: baselen == 0 || base[baselen-1] == '/'
*
* Return:
* - 2 for "yes, and all subsequent entries will be"
* - 1 for yes
* - zero for no
* - negative for "no, and no subsequent entries will be either"
*/
static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt)
{
const char *path;
const unsigned char *sha1;
unsigned mode;
int i;
int pathlen;
int never_interesting = -1;
if (!opt->nr_paths)
return 2;
sha1 = tree_entry_extract(desc, &path, &mode);
pathlen = tree_entry_len(path, sha1);
for (i = 0; i < opt->nr_paths; i++) {
const char *match = opt->paths[i];
int matchlen = opt->pathlens[i];
int m = -1; /* signals that we haven't called strncmp() */
if (baselen >= matchlen) {
/* If it doesn't match, move along... */
if (strncmp(base, match, matchlen))
continue;
/*
* If the base is a subdirectory of a path which
* was specified, all of them are interesting.
*/
if (!matchlen ||
base[matchlen] == '/' ||
match[matchlen - 1] == '/')
return 2;
/* Just a random prefix match */
continue;
}
/* Does the base match? */
if (strncmp(base, match, baselen))
continue;
match += baselen;
matchlen -= baselen;
if (never_interesting) {
/*
* We have not seen any match that sorts later
* than the current path.
*/
/*
* Does match sort strictly earlier than path
* with their common parts?
*/
m = strncmp(match, path,
(matchlen < pathlen) ? matchlen : pathlen);
if (m < 0)
continue;
/*
* If we come here even once, that means there is at
* least one pathspec that would sort equal to or
* later than the path we are currently looking at.
* In other words, if we have never reached this point
* after iterating all pathspecs, it means all
* pathspecs are either outside of base, or inside the
* base but sorts strictly earlier than the current
* one. In either case, they will never match the
* subsequent entries. In such a case, we initialized
* the variable to -1 and that is what will be
* returned, allowing the caller to terminate early.
*/
never_interesting = 0;
}
if (pathlen > matchlen)
continue;
if (matchlen > pathlen) {
if (match[pathlen] != '/')
continue;
if (!S_ISDIR(mode))
continue;
}
if (m == -1)
/*
* we cheated and did not do strncmp(), so we do
* that here.
*/
m = strncmp(match, path, pathlen);
/*
* If common part matched earlier then it is a hit,
* because we rejected the case where path is not a
* leading directory and is shorter than match.
*/
if (!m)
return 1;
}
return never_interesting; /* No matches */
}
/* A whole sub-tree went away or appeared */
static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen)
{
int all_interesting = 0;
while (desc->size) {
int show;
if (all_interesting)
show = 1;
else {
show = tree_entry_interesting(desc, base, baselen,
opt);
if (show == 2)
all_interesting = 1;
}
if (show < 0)
break;
if (show)
show_entry(opt, prefix, desc, base, baselen);
update_tree_entry(desc);
}
}
/* A file entry went away or appeared */
static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
const char *base, int baselen)
{
unsigned mode;
const char *path;
const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
int pathlen = tree_entry_len(path, sha1);
if (DIFF_OPT_TST(opt, RECURSIVE) && S_ISDIR(mode)) {
enum object_type type;
char *newbase = malloc_base(base, baselen, path, pathlen);
struct tree_desc inner;
void *tree;
unsigned long size;
tree = read_sha1_file(sha1, &type, &size);
if (!tree || type != OBJ_TREE)
die("corrupt tree sha %s", sha1_to_hex(sha1));
if (DIFF_OPT_TST(opt, TREE_IN_RECURSIVE)) {
newbase[baselen + pathlen] = 0;
opt->add_remove(opt, *prefix, mode, sha1, newbase, 0);
newbase[baselen + pathlen] = '/';
}
init_tree_desc(&inner, tree, size);
show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
free(tree);
free(newbase);
} else {
char *fullname = malloc_fullname(base, baselen, path, pathlen);
opt->add_remove(opt, prefix[0], mode, sha1, fullname, 0);
free(fullname);
}
}
static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt, int *all_interesting)
{
while (t->size) {
int show = tree_entry_interesting(t, base, baselen, opt);
if (show == 2)
*all_interesting = 1;
if (!show) {
update_tree_entry(t);
continue;
}
/* Skip it all? */
if (show < 0)
t->size = 0;
return;
}
}
int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
int baselen = strlen(base);
int all_t1_interesting = 0;
int all_t2_interesting = 0;
for (;;) {
if (DIFF_OPT_TST(opt, QUICK) &&
DIFF_OPT_TST(opt, HAS_CHANGES))
break;
if (opt->nr_paths) {
if (!all_t1_interesting)
skip_uninteresting(t1, base, baselen, opt,
&all_t1_interesting);
if (!all_t2_interesting)
skip_uninteresting(t2, base, baselen, opt,
&all_t2_interesting);
}
if (!t1->size) {
if (!t2->size)
break;
show_entry(opt, "+", t2, base, baselen);
update_tree_entry(t2);
continue;
}
if (!t2->size) {
show_entry(opt, "-", t1, base, baselen);
update_tree_entry(t1);
continue;
}
switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
case -1:
update_tree_entry(t1);
continue;
case 0:
update_tree_entry(t1);
/* Fallthrough */
case 1:
update_tree_entry(t2);
continue;
}
die("git diff-tree: internal error");
}
return 0;
}
/*
* Does it look like the resulting diff might be due to a rename?
* - single entry
* - not a valid previous file
*/
static inline int diff_might_be_rename(void)
{
return diff_queued_diff.nr == 1 &&
!DIFF_FILE_VALID(diff_queued_diff.queue[0]->one);
}
static void try_to_follow_renames(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
{
struct diff_options diff_opts;
struct diff_queue_struct *q = &diff_queued_diff;
struct diff_filepair *choice;
const char *paths[1];
int i;
/* Remove the file creation entry from the diff queue, and remember it */
choice = q->queue[0];
q->nr = 0;
diff_setup(&diff_opts);
DIFF_OPT_SET(&diff_opts, RECURSIVE);
DIFF_OPT_SET(&diff_opts, FIND_COPIES_HARDER);
diff_opts.output_format = DIFF_FORMAT_NO_OUTPUT;
diff_opts.single_follow = opt->paths[0];
diff_opts.break_opt = opt->break_opt;
paths[0] = NULL;
diff_tree_setup_paths(paths, &diff_opts);
if (diff_setup_done(&diff_opts) < 0)
die("unable to set up diff options to follow renames");
diff_tree(t1, t2, base, &diff_opts);
diffcore_std(&diff_opts);
diff_tree_release_paths(&diff_opts);
/* Go through the new set of filepairing, and see if we find a more interesting one */
opt->found_follow = 0;
for (i = 0; i < q->nr; i++) {
struct diff_filepair *p = q->queue[i];
/*
* Found a source? Not only do we use that for the new
* diff_queued_diff, we will also use that as the path in
* the future!
*/
if ((p->status == 'R' || p->status == 'C') && !strcmp(p->two->path, opt->paths[0])) {
/* Switch the file-pairs around */
q->queue[i] = choice;
choice = p;
/* Update the path we use from now on.. */
diff_tree_release_paths(opt);
opt->paths[0] = xstrdup(p->one->path);
diff_tree_setup_paths(opt->paths, opt);
/*
* The caller expects us to return a set of vanilla
* filepairs to let a later call to diffcore_std()
* it makes to sort the renames out (among other
* things), but we already have found renames
* ourselves; signal diffcore_std() not to muck with
* rename information.
*/
opt->found_follow = 1;
break;
}
}
/*
* Then, discard all the non-relevant file pairs...
*/
for (i = 0; i < q->nr; i++) {
struct diff_filepair *p = q->queue[i];
diff_free_filepair(p);
}
/*
* .. and re-instate the one we want (which might be either the
* original one, or the rename/copy we found)
*/
q->queue[0] = choice;
q->nr = 1;
}
int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const char *base, struct diff_options *opt)
{
void *tree1, *tree2;
struct tree_desc t1, t2;
unsigned long size1, size2;
int retval;
tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
if (!tree1)
die("unable to read source tree (%s)", sha1_to_hex(old));
tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
if (!tree2)
die("unable to read destination tree (%s)", sha1_to_hex(new));
init_tree_desc(&t1, tree1, size1);
init_tree_desc(&t2, tree2, size2);
retval = diff_tree(&t1, &t2, base, opt);
if (!*base && DIFF_OPT_TST(opt, FOLLOW_RENAMES) && diff_might_be_rename()) {
init_tree_desc(&t1, tree1, size1);
init_tree_desc(&t2, tree2, size2);
try_to_follow_renames(&t1, &t2, base, opt);
}
free(tree1);
free(tree2);
return retval;
}
int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
{
int retval;
void *tree;
unsigned long size;
struct tree_desc empty, real;
tree = read_object_with_reference(new, tree_type, &size, NULL);
if (!tree)
die("unable to read root tree (%s)", sha1_to_hex(new));
init_tree_desc(&real, tree, size);
init_tree_desc(&empty, "", 0);
retval = diff_tree(&empty, &real, base, opt);
free(tree);
return retval;
}
static int count_paths(const char **paths)
{
int i = 0;
while (*paths++)
i++;
return i;
}
void diff_tree_release_paths(struct diff_options *opt)
{
free(opt->pathlens);
}
void diff_tree_setup_paths(const char **p, struct diff_options *opt)
{
opt->nr_paths = 0;
opt->pathlens = NULL;
opt->paths = NULL;
if (p) {
int i;
opt->paths = p;
opt->nr_paths = count_paths(p);
if (opt->nr_paths == 0) {
opt->pathlens = NULL;
return;
}
opt->pathlens = xmalloc(opt->nr_paths * sizeof(int));
for (i=0; i < opt->nr_paths; i++)
opt->pathlens[i] = strlen(p[i]);
}
}
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