X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=sha1_name.c;h=4f92e12a8dfce29b5bb50108468259d9f04653f3;hb=5cf7e21fbc1819de7975b17f4b19cfdc3a057c1d;hp=be1755a70b2c53fc102db41a62e6099fa0adac1b;hpb=6ddc0964034342519a87fe013781abf31c6db6ad;p=git.git

diff --git a/sha1_name.c b/sha1_name.c
index be1755a7..4f92e12a 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -143,7 +143,7 @@ static int find_unique_short_object(int len, char *canonical,
 	}
 	/* Both have unique ones -- do they match? */
 	if (memcmp(packed_sha1, unpacked_sha1, 20))
-		return -2;
+		return SHORT_NAME_AMBIGUOUS;
 	memcpy(sha1, packed_sha1, 20);
 	return 0;
 }
@@ -155,7 +155,7 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1,
 	char canonical[40];
 	unsigned char res[20];
 
-	if (len < 4)
+	if (len < MINIMUM_ABBREV)
 		return -1;
 	memset(res, 0, 20);
 	memset(canonical, 'x', 40);
@@ -186,13 +186,18 @@ static int get_short_sha1(const char *name, int len, unsigned char *sha1,
 
 const char *find_unique_abbrev(const unsigned char *sha1, int len)
 {
-	int status;
+	int status, is_null;
 	static char hex[41];
+
+	is_null = !memcmp(sha1, null_sha1, 20);
 	memcpy(hex, sha1_to_hex(sha1), 40);
+	if (len == 40)
+		return hex;
 	while (len < 40) {
 		unsigned char sha1_ret[20];
 		status = get_short_sha1(hex, len, sha1_ret, 1);
-		if (!status) {
+		if (!status ||
+		    (is_null && status != SHORT_NAME_AMBIGUOUS)) {
 			hex[len] = 0;
 			return hex;
 		}
@@ -203,11 +208,12 @@ const char *find_unique_abbrev(const unsigned char *sha1, int len)
 	return NULL;
 }
 
-static int ambiguous_path(const char *path)
+static int ambiguous_path(const char *path, int len)
 {
 	int slash = 1;
+	int cnt;
 
-	for (;;) {
+	for (cnt = 0; cnt < len; cnt++) {
 		switch (*path++) {
 		case '\0':
 			break;
@@ -222,34 +228,51 @@ static int ambiguous_path(const char *path)
 			slash = 0;
 			continue;
 		}
-		return slash;
+		break;
 	}
+	return slash;
 }
 
 static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 {
-	static const char *prefix[] = {
-		"",
-		"refs",
-		"refs/tags",
-		"refs/heads",
+	static const char *fmt[] = {
+		"%.*s",
+		"refs/%.*s",
+		"refs/tags/%.*s",
+		"refs/heads/%.*s",
+		"refs/remotes/%.*s",
+		"refs/remotes/%.*s/HEAD",
 		NULL
 	};
 	const char **p;
+	const char *warning = "warning: refname '%.*s' is ambiguous.\n";
+	char *pathname;
+	int already_found = 0;
+	unsigned char *this_result;
+	unsigned char sha1_from_ref[20];
 
 	if (len == 40 && !get_sha1_hex(str, sha1))
 		return 0;
 
 	/* Accept only unambiguous ref paths. */
-	if (ambiguous_path(str))
+	if (ambiguous_path(str, len))
 		return -1;
 
-	for (p = prefix; *p; p++) {
-		char *pathname = git_path("%s/%.*s", *p, len, str);
-		if (!read_ref(pathname, sha1))
-			return 0;
+	for (p = fmt; *p; p++) {
+		this_result = already_found ? sha1_from_ref : sha1;
+		pathname = git_path(*p, len, str);
+		if (!read_ref(pathname, this_result)) {
+			if (warn_ambiguous_refs) {
+				if (already_found)
+					fprintf(stderr, warning, len, str);
+				already_found++;
+			}
+			else
+				return 0;
+		}
 	}
-
+	if (already_found)
+		return 0;
 	return -1;
 }
 
@@ -384,43 +407,36 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
 
 static int get_sha1_1(const char *name, int len, unsigned char *sha1)
 {
-	int parent, ret;
+	int ret, has_suffix;
 	const char *cp;
 
-	/* foo^[0-9] or foo^ (== foo^1); we do not do more than 9 parents. */
-	if (len > 2 && name[len-2] == '^' &&
-	    name[len-1] >= '0' && name[len-1] <= '9') {
-		parent = name[len-1] - '0';
-		len -= 2;
-	}
-	else if (len > 1 && name[len-1] == '^') {
-		parent = 1;
-		len--;
-	} else
-		parent = -1;
-
-	if (parent >= 0)
-		return get_parent(name, len, sha1, parent);
-
 	/* "name~3" is "name^^^",
-	 * "name~12" is "name^^^^^^^^^^^^", and
 	 * "name~" and "name~0" are name -- not "name^0"!
+	 * "name^" is not "name^0"; it is "name^1".
 	 */
-	parent = 0;
+	has_suffix = 0;
 	for (cp = name + len - 1; name <= cp; cp--) {
 		int ch = *cp;
 		if ('0' <= ch && ch <= '9')
 			continue;
-		if (ch != '~')
-			parent = -1;
+		if (ch == '~' || ch == '^')
+			has_suffix = ch;
 		break;
 	}
-	if (!parent && *cp == '~') {
+
+	if (has_suffix) {
+		int num = 0;
 		int len1 = cp - name;
 		cp++;
 		while (cp < name + len)
-			parent = parent * 10 + *cp++ - '0';
-		return get_nth_ancestor(name, len1, sha1, parent);
+			num = num * 10 + *cp++ - '0';
+		if (has_suffix == '^') {
+			if (!num && len1 == len - 1)
+				num = 1;
+			return get_parent(name, len1, sha1, num);
+		}
+		/* else if (has_suffix == '~') -- goes without saying */
+		return get_nth_ancestor(name, len1, sha1, num);
 	}
 
 	ret = peel_onion(name, len, sha1);