475 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
			
		
		
	
	
			475 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
| #include "cache.h"
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| #include "tag.h"
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| #include "commit.h"
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| #include "tree.h"
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| #include "blob.h"
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| #include "tree-walk.h"
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| 
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| static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
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| {
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| 	struct alternate_object_database *alt;
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| 	char hex[40];
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| 	int found = 0;
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| 	static struct alternate_object_database *fakeent;
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| 
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| 	if (!fakeent) {
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| 		const char *objdir = get_object_directory();
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| 		int objdir_len = strlen(objdir);
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| 		int entlen = objdir_len + 43;
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| 		fakeent = xmalloc(sizeof(*fakeent) + entlen);
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| 		memcpy(fakeent->base, objdir, objdir_len);
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| 		fakeent->name = fakeent->base + objdir_len + 1;
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| 		fakeent->name[-1] = '/';
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| 	}
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| 	fakeent->next = alt_odb_list;
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| 
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| 	sprintf(hex, "%.2s", name);
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| 	for (alt = fakeent; alt && found < 2; alt = alt->next) {
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| 		struct dirent *de;
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| 		DIR *dir;
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| 		sprintf(alt->name, "%.2s/", name);
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| 		dir = opendir(alt->base);
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| 		if (!dir)
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| 			continue;
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| 		while ((de = readdir(dir)) != NULL) {
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| 			if (strlen(de->d_name) != 38)
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| 				continue;
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| 			if (memcmp(de->d_name, name + 2, len - 2))
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| 				continue;
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| 			if (!found) {
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| 				memcpy(hex + 2, de->d_name, 38);
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| 				found++;
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| 			}
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| 			else if (memcmp(hex + 2, de->d_name, 38)) {
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| 				found = 2;
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| 				break;
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| 			}
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| 		}
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| 		closedir(dir);
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| 	}
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| 	if (found == 1)
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| 		return get_sha1_hex(hex, sha1) == 0;
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| 	return found;
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| }
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| 
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| static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
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| {
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| 	do {
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| 		if (*a != *b)
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| 			return 0;
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| 		a++;
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| 		b++;
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| 		len -= 2;
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| 	} while (len > 1);
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| 	if (len)
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| 		if ((*a ^ *b) & 0xf0)
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| 			return 0;
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| 	return 1;
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| }
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| 
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| static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
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| {
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| 	struct packed_git *p;
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| 	unsigned char found_sha1[20];
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| 	int found = 0;
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| 
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| 	prepare_packed_git();
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| 	for (p = packed_git; p && found < 2; p = p->next) {
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| 		unsigned num = num_packed_objects(p);
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| 		unsigned first = 0, last = num;
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| 		while (first < last) {
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| 			unsigned mid = (first + last) / 2;
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| 			unsigned char now[20];
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| 			int cmp;
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| 
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| 			nth_packed_object_sha1(p, mid, now);
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| 			cmp = memcmp(match, now, 20);
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| 			if (!cmp) {
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| 				first = mid;
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| 				break;
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| 			}
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| 			if (cmp > 0) {
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| 				first = mid+1;
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| 				continue;
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| 			}
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| 			last = mid;
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| 		}
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| 		if (first < num) {
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| 			unsigned char now[20], next[20];
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| 			nth_packed_object_sha1(p, first, now);
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| 			if (match_sha(len, match, now)) {
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| 				if (nth_packed_object_sha1(p, first+1, next) ||
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| 				    !match_sha(len, match, next)) {
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| 					/* unique within this pack */
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| 					if (!found) {
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| 						memcpy(found_sha1, now, 20);
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| 						found++;
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| 					}
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| 					else if (memcmp(found_sha1, now, 20)) {
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| 						found = 2;
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| 						break;
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| 					}
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| 				}
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| 				else {
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| 					/* not even unique within this pack */
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| 					found = 2;
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| 					break;
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| 				}
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| 			}
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| 		}
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| 	}
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| 	if (found == 1)
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| 		memcpy(sha1, found_sha1, 20);
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| 	return found;
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| }
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| 
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| #define SHORT_NAME_NOT_FOUND (-1)
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| #define SHORT_NAME_AMBIGUOUS (-2)
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| 
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| static int find_unique_short_object(int len, char *canonical,
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| 				    unsigned char *res, unsigned char *sha1)
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| {
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| 	int has_unpacked, has_packed;
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| 	unsigned char unpacked_sha1[20], packed_sha1[20];
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| 
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| 	has_unpacked = find_short_object_filename(len, canonical, unpacked_sha1);
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| 	has_packed = find_short_packed_object(len, res, packed_sha1);
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| 	if (!has_unpacked && !has_packed)
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| 		return SHORT_NAME_NOT_FOUND;
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| 	if (1 < has_unpacked || 1 < has_packed)
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| 		return SHORT_NAME_AMBIGUOUS;
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| 	if (has_unpacked != has_packed) {
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| 		memcpy(sha1, (has_packed ? packed_sha1 : unpacked_sha1), 20);
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| 		return 0;
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| 	}
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| 	/* Both have unique ones -- do they match? */
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| 	if (memcmp(packed_sha1, unpacked_sha1, 20))
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| 		return SHORT_NAME_AMBIGUOUS;
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| 	memcpy(sha1, packed_sha1, 20);
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| 	return 0;
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| }
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| 
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| static int get_short_sha1(const char *name, int len, unsigned char *sha1,
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| 			  int quietly)
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| {
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| 	int i, status;
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| 	char canonical[40];
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| 	unsigned char res[20];
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| 
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| 	if (len < MINIMUM_ABBREV)
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| 		return -1;
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| 	memset(res, 0, 20);
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| 	memset(canonical, 'x', 40);
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| 	for (i = 0; i < len ;i++) {
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| 		unsigned char c = name[i];
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| 		unsigned char val;
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| 		if (c >= '0' && c <= '9')
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| 			val = c - '0';
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| 		else if (c >= 'a' && c <= 'f')
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| 			val = c - 'a' + 10;
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| 		else if (c >= 'A' && c <='F') {
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| 			val = c - 'A' + 10;
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| 			c -= 'A' - 'a';
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| 		}
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| 		else
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| 			return -1;
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| 		canonical[i] = c;
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| 		if (!(i & 1))
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| 			val <<= 4;
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| 		res[i >> 1] |= val;
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| 	}
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| 
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| 	status = find_unique_short_object(i, canonical, res, sha1);
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| 	if (!quietly && (status == SHORT_NAME_AMBIGUOUS))
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| 		return error("short SHA1 %.*s is ambiguous.", len, canonical);
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| 	return status;
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| }
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| 
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| const char *find_unique_abbrev(const unsigned char *sha1, int len)
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| {
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| 	int status, is_null;
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| 	static char hex[41];
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| 
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| 	is_null = !memcmp(sha1, null_sha1, 20);
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| 	memcpy(hex, sha1_to_hex(sha1), 40);
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| 	if (len == 40)
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| 		return hex;
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| 	while (len < 40) {
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| 		unsigned char sha1_ret[20];
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| 		status = get_short_sha1(hex, len, sha1_ret, 1);
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| 		if (!status ||
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| 		    (is_null && status != SHORT_NAME_AMBIGUOUS)) {
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| 			hex[len] = 0;
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| 			return hex;
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| 		}
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| 		if (status != SHORT_NAME_AMBIGUOUS)
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| 			return NULL;
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| 		len++;
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| 	}
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| 	return NULL;
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| }
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| 
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| static int ambiguous_path(const char *path, int len)
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| {
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| 	int slash = 1;
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| 	int cnt;
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| 
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| 	for (cnt = 0; cnt < len; cnt++) {
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| 		switch (*path++) {
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| 		case '\0':
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| 			break;
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| 		case '/':
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| 			if (slash)
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| 				break;
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| 			slash = 1;
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| 			continue;
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| 		case '.':
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| 			continue;
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| 		default:
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| 			slash = 0;
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| 			continue;
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| 		}
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| 		break;
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| 	}
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| 	return slash;
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| }
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| 
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| static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
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| {
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| 	static const char *fmt[] = {
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| 		"%.*s",
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| 		"refs/%.*s",
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| 		"refs/tags/%.*s",
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| 		"refs/heads/%.*s",
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| 		"refs/remotes/%.*s",
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| 		"refs/remotes/%.*s/HEAD",
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| 		NULL
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| 	};
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| 	const char **p;
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| 	const char *warning = "warning: refname '%.*s' is ambiguous.\n";
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| 	char *pathname;
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| 	int already_found = 0;
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| 	unsigned char *this_result;
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| 	unsigned char sha1_from_ref[20];
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| 
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| 	if (len == 40 && !get_sha1_hex(str, sha1))
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| 		return 0;
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| 
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| 	/* Accept only unambiguous ref paths. */
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| 	if (ambiguous_path(str, len))
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| 		return -1;
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| 
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| 	for (p = fmt; *p; p++) {
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| 		this_result = already_found ? sha1_from_ref : sha1;
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| 		pathname = git_path(*p, len, str);
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| 		if (!read_ref(pathname, this_result)) {
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| 			if (warn_ambiguous_refs) {
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| 				if (already_found)
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| 					fprintf(stderr, warning, len, str);
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| 				already_found++;
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| 			}
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| 			else
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| 				return 0;
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| 		}
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| 	}
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| 	if (already_found)
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| 		return 0;
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| 	return -1;
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| }
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| 
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| static int get_sha1_1(const char *name, int len, unsigned char *sha1);
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| 
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| static int get_parent(const char *name, int len,
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| 		      unsigned char *result, int idx)
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| {
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| 	unsigned char sha1[20];
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| 	int ret = get_sha1_1(name, len, sha1);
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| 	struct commit *commit;
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| 	struct commit_list *p;
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| 
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| 	if (ret)
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| 		return ret;
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| 	commit = lookup_commit_reference(sha1);
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| 	if (!commit)
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| 		return -1;
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| 	if (parse_commit(commit))
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| 		return -1;
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| 	if (!idx) {
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| 		memcpy(result, commit->object.sha1, 20);
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| 		return 0;
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| 	}
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| 	p = commit->parents;
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| 	while (p) {
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| 		if (!--idx) {
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| 			memcpy(result, p->item->object.sha1, 20);
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| 			return 0;
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| 		}
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| 		p = p->next;
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| 	}
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| 	return -1;
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| }
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| 
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| static int get_nth_ancestor(const char *name, int len,
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| 			    unsigned char *result, int generation)
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| {
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| 	unsigned char sha1[20];
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| 	int ret = get_sha1_1(name, len, sha1);
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| 	if (ret)
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| 		return ret;
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| 
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| 	while (generation--) {
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| 		struct commit *commit = lookup_commit_reference(sha1);
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| 
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| 		if (!commit || parse_commit(commit) || !commit->parents)
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| 			return -1;
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| 		memcpy(sha1, commit->parents->item->object.sha1, 20);
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| 	}
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| 	memcpy(result, sha1, 20);
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| 	return 0;
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| }
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| 
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| static int peel_onion(const char *name, int len, unsigned char *sha1)
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| {
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| 	unsigned char outer[20];
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| 	const char *sp;
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| 	const char *type_string = NULL;
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| 	struct object *o;
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| 
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| 	/*
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| 	 * "ref^{type}" dereferences ref repeatedly until you cannot
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| 	 * dereference anymore, or you get an object of given type,
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| 	 * whichever comes first.  "ref^{}" means just dereference
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| 	 * tags until you get a non-tag.  "ref^0" is a shorthand for
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| 	 * "ref^{commit}".  "commit^{tree}" could be used to find the
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| 	 * top-level tree of the given commit.
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| 	 */
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| 	if (len < 4 || name[len-1] != '}')
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| 		return -1;
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| 
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| 	for (sp = name + len - 1; name <= sp; sp--) {
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| 		int ch = *sp;
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| 		if (ch == '{' && name < sp && sp[-1] == '^')
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| 			break;
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| 	}
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| 	if (sp <= name)
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| 		return -1;
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| 
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| 	sp++; /* beginning of type name, or closing brace for empty */
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| 	if (!strncmp(commit_type, sp, 6) && sp[6] == '}')
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| 		type_string = commit_type;
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| 	else if (!strncmp(tree_type, sp, 4) && sp[4] == '}')
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| 		type_string = tree_type;
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| 	else if (!strncmp(blob_type, sp, 4) && sp[4] == '}')
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| 		type_string = blob_type;
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| 	else if (sp[0] == '}')
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| 		type_string = NULL;
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| 	else
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| 		return -1;
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| 
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| 	if (get_sha1_1(name, sp - name - 2, outer))
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| 		return -1;
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| 
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| 	o = parse_object(outer);
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| 	if (!o)
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| 		return -1;
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| 	if (!type_string) {
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| 		o = deref_tag(o, name, sp - name - 2);
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| 		if (!o || (!o->parsed && !parse_object(o->sha1)))
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| 			return -1;
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| 		memcpy(sha1, o->sha1, 20);
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| 	}
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| 	else {
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| 		/* At this point, the syntax look correct, so
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| 		 * if we do not get the needed object, we should
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| 		 * barf.
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| 		 */
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| 
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| 		while (1) {
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| 			if (!o || (!o->parsed && !parse_object(o->sha1)))
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| 				return -1;
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| 			if (o->type == type_string) {
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| 				memcpy(sha1, o->sha1, 20);
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| 				return 0;
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| 			}
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| 			if (o->type == tag_type)
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| 				o = ((struct tag*) o)->tagged;
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| 			else if (o->type == commit_type)
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| 				o = &(((struct commit *) o)->tree->object);
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| 			else
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| 				return error("%.*s: expected %s type, but the object dereferences to %s type",
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| 					     len, name, type_string,
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| 					     o->type);
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| 			if (!o->parsed)
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| 				parse_object(o->sha1);
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| 		}
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| 	}
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| 	return 0;
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| }
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| 
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| static int get_sha1_1(const char *name, int len, unsigned char *sha1)
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| {
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| 	int ret, has_suffix;
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| 	const char *cp;
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| 
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| 	/* "name~3" is "name^^^",
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| 	 * "name~" and "name~0" are name -- not "name^0"!
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| 	 * "name^" is not "name^0"; it is "name^1".
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| 	 */
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| 	has_suffix = 0;
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| 	for (cp = name + len - 1; name <= cp; cp--) {
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| 		int ch = *cp;
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| 		if ('0' <= ch && ch <= '9')
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| 			continue;
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| 		if (ch == '~' || ch == '^')
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| 			has_suffix = ch;
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| 		break;
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| 	}
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| 
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| 	if (has_suffix) {
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| 		int num = 0;
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| 		int len1 = cp - name;
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| 		cp++;
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| 		while (cp < name + len)
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| 			num = num * 10 + *cp++ - '0';
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| 		if (has_suffix == '^') {
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| 			if (!num && len1 == len - 1)
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| 				num = 1;
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| 			return get_parent(name, len1, sha1, num);
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| 		}
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| 		/* else if (has_suffix == '~') -- goes without saying */
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| 		return get_nth_ancestor(name, len1, sha1, num);
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| 	}
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| 
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| 	ret = peel_onion(name, len, sha1);
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| 	if (!ret)
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| 		return 0;
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| 
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| 	ret = get_sha1_basic(name, len, sha1);
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| 	if (!ret)
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| 		return 0;
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| 	return get_short_sha1(name, len, sha1, 0);
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| }
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| 
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| /*
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|  * This is like "get_sha1_basic()", except it allows "sha1 expressions",
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|  * notably "xyz^" for "parent of xyz"
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|  */
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| int get_sha1(const char *name, unsigned char *sha1)
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| {
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| 	int ret;
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| 	unsigned unused;
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| 
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| 	prepare_alt_odb();
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| 	ret = get_sha1_1(name, strlen(name), sha1);
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| 	if (ret < 0) {
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| 		const char *cp = strchr(name, ':');
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| 		if (cp) {
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| 			unsigned char tree_sha1[20];
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| 			if (!get_sha1_1(name, cp-name, tree_sha1))
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| 				return get_tree_entry(tree_sha1, cp+1, sha1,
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| 						      &unused);
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| 		}
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| 	}
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| 	return ret;
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| }
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