X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=sha1_name.c;h=4f92e12a8dfce29b5bb50108468259d9f04653f3;hb=be0c7e069738fbb697b0719f2252107261c9340e;hp=fa85d8a88d31219cef5bed195044327459f9162b;hpb=90768daaa006516c7ae69ed89d7c2e67243dfac1;p=git.git

diff --git a/sha1_name.c b/sha1_name.c
index fa85d8a8..4f92e12a 100644
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -186,16 +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;
 		}
@@ -233,14 +235,21 @@ static int ambiguous_path(const char *path, int len)
 
 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;
@@ -249,11 +258,21 @@ static int get_sha1_basic(const char *str, int len, unsigned char *sha1)
 	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;
 }