git-commit-vandalism/write-tree.c
Junio C Hamano 8eef4d3ed1 Notice index that has path and path/file and refuse to write such a tree.
Kay Sievers noticed that you can have both path and path/file in
the cache and write-tree happily creates a tree object from such
a state.  Since a merge can result in such situation and the
user should be able to see the situation by looking at the
cache, rather than forbidding add_cache_entry() to create such
conflicts, fix it by making write-tree refuse to write such an
nonsensical tree.  Here is a test case.

-- test case --

$ ls -a
./  ../
$ git-init-db
defaulting to local storage area
$ date >path
$ git-update-cache --add path
$ rm path
$ mkdir path
$ date >path/file
$ git-update-cache --add path/file
$ git-ls-files --stage
100644 1738f2536b1201218c41153941da065cc26174c9 0 path
100644 620c72f1c1de15f56ff9d63d6d7cdc69e828f1e3 0 path/file
$ git-ls-tree $(git-write-tree)                     ;# using old one
100644	blob	1738f2536b1201218c41153941da065cc26174c9	path
040000	tree	ec116937f223e3df95aeac9f076902ae1618ae98	path
$ ../git-write-tree                                 ;# using new one
You have both path and path/file
fatal: write-tree: not able to write tree
$ exit

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-05-07 12:22:02 -07:00

142 lines
3.6 KiB
C

/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
static int check_valid_sha1(unsigned char *sha1)
{
char *filename = sha1_file_name(sha1);
int ret;
/* If we were anal, we'd check that the sha1 of the contents actually matches */
ret = access(filename, R_OK);
if (ret)
perror(filename);
return ret;
}
static int write_tree(struct cache_entry **cachep, int maxentries, const char *base, int baselen, unsigned char *returnsha1)
{
unsigned char subdir_sha1[20];
unsigned long size, offset;
char *buffer;
int nr;
/* Guess at some random initial size */
size = 8192;
buffer = xmalloc(size);
offset = 0;
nr = 0;
do {
struct cache_entry *ce = cachep[nr];
const char *pathname = ce->name, *filename, *dirname;
int pathlen = ce_namelen(ce), entrylen;
unsigned char *sha1;
unsigned int mode;
/* Did we hit the end of the directory? Return how many we wrote */
if (baselen >= pathlen || memcmp(base, pathname, baselen))
break;
sha1 = ce->sha1;
mode = ntohl(ce->ce_mode);
/* Do we have _further_ subdirectories? */
filename = pathname + baselen;
dirname = strchr(filename, '/');
if (dirname) {
int subdir_written;
subdir_written = write_tree(cachep + nr, maxentries - nr, pathname, dirname-pathname+1, subdir_sha1);
nr += subdir_written;
/* Now we need to write out the directory entry into this tree.. */
mode = S_IFDIR;
pathlen = dirname - pathname;
/* ..but the directory entry doesn't count towards the total count */
nr--;
sha1 = subdir_sha1;
}
if (check_valid_sha1(sha1) < 0)
exit(1);
entrylen = pathlen - baselen;
if (offset + entrylen + 100 > size) {
size = alloc_nr(offset + entrylen + 100);
buffer = xrealloc(buffer, size);
}
offset += sprintf(buffer + offset, "%o %.*s", mode, entrylen, filename);
buffer[offset++] = 0;
memcpy(buffer + offset, sha1, 20);
offset += 20;
nr++;
} while (nr < maxentries);
write_sha1_file(buffer, offset, "tree", returnsha1);
free(buffer);
return nr;
}
int main(int argc, char **argv)
{
int i, funny;
int entries = read_cache();
unsigned char sha1[20];
if (entries <= 0)
die("write-tree: no cache contents to write");
/* Verify that the tree is merged */
funny = 0;
for (i = 0; i < entries; i++) {
struct cache_entry *ce = active_cache[i];
if (ntohs(ce->ce_flags) & ~CE_NAMEMASK) {
if (10 < ++funny) {
fprintf(stderr, "...\n");
break;
}
fprintf(stderr, "%s: unmerged (%s)\n", ce->name, sha1_to_hex(ce->sha1));
}
}
if (funny)
die("write-tree: not able to write tree");
/* Also verify that the cache does not have path and path/file
* at the same time. At this point we know the cache has only
* stage 0 entries.
*/
funny = 0;
for (i = 0; i < entries - 1; i++) {
/* path/file always comes after path because of the way
* the cache is sorted. Also path can appear only once,
* which means conflicting one would immediately follow.
*/
const char *this_name = active_cache[i]->name;
const char *next_name = active_cache[i+1]->name;
int this_len = strlen(this_name);
if (this_len < strlen(next_name) &&
strncmp(this_name, next_name, this_len) == 0 &&
next_name[this_len] == '/') {
if (10 < ++funny) {
fprintf(stderr, "...\n");
break;
}
fprintf(stderr, "You have both %s and %s\n",
this_name, next_name);
}
}
if (funny)
die("write-tree: not able to write tree");
/* Ok, write it out */
if (write_tree(active_cache, entries, "", 0, sha1) != entries)
die("write-tree: internal error");
printf("%s\n", sha1_to_hex(sha1));
return 0;
}