X-Git-Url: https://git.octo.it/?a=blobdiff_plain;ds=sidebyside;f=refs.c;h=5a8cbd4ef386da60d3f7a2cac4563fc993e38b94;hb=a7a8d3786e6b60a472d0f88f778cacaead122a6c;hp=d4f3612487c0b9775d1baa382549b019beeef262;hpb=ca8db1424d1808a1f78bc9905efd267f7c154d8e;p=git.git

diff --git a/refs.c b/refs.c
index d4f36124..5a8cbd4e 100644
--- a/refs.c
+++ b/refs.c
@@ -7,40 +7,152 @@
 /* We allow "recursive" symbolic refs. Only within reason, though */
 #define MAXDEPTH 5
 
-int read_ref(const char *filename, unsigned char *sha1)
+#ifndef USE_SYMLINK_HEAD
+#define USE_SYMLINK_HEAD 1
+#endif
+
+int validate_symref(const char *path)
+{
+	struct stat st;
+	char *buf, buffer[256];
+	int len, fd;
+
+	if (lstat(path, &st) < 0)
+		return -1;
+
+	/* Make sure it is a "refs/.." symlink */
+	if (S_ISLNK(st.st_mode)) {
+		len = readlink(path, buffer, sizeof(buffer)-1);
+		if (len >= 5 && !memcmp("refs/", buffer, 5))
+			return 0;
+		return -1;
+	}
+
+	/*
+	 * Anything else, just open it and try to see if it is a symbolic ref.
+	 */
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return -1;
+	len = read(fd, buffer, sizeof(buffer)-1);
+	close(fd);
+
+	/*
+	 * Is it a symbolic ref?
+	 */
+	if (len < 4 || memcmp("ref:", buffer, 4))
+		return -1;
+	buf = buffer + 4;
+	len -= 4;
+	while (len && isspace(*buf))
+		buf++, len--;
+	if (len >= 5 && !memcmp("refs/", buf, 5))
+		return 0;
+	return -1;
+}
+
+const char *resolve_ref(const char *path, unsigned char *sha1, int reading)
 {
-	int depth = 0;
-	int ret = -1, fd;
+	int depth = MAXDEPTH, len;
+	char buffer[256];
+
+	for (;;) {
+		struct stat st;
+		char *buf;
+		int fd;
 
-	while ((fd = open(filename, O_RDONLY)) >= 0) {
-		char buffer[256];
-		int len = read(fd, buffer, sizeof(buffer)-1);
+		if (--depth < 0)
+			return NULL;
 
+		/* Special case: non-existing file.
+		 * Not having the refs/heads/new-branch is OK
+		 * if we are writing into it, so is .git/HEAD
+		 * that points at refs/heads/master still to be
+		 * born.  It is NOT OK if we are resolving for
+		 * reading.
+		 */
+		if (lstat(path, &st) < 0) {
+			if (reading || errno != ENOENT)
+				return NULL;
+			memset(sha1, 0, 20);
+			return path;
+		}
+
+		/* Follow "normalized" - ie "refs/.." symlinks by hand */
+		if (S_ISLNK(st.st_mode)) {
+			len = readlink(path, buffer, sizeof(buffer)-1);
+			if (len >= 5 && !memcmp("refs/", buffer, 5)) {
+				path = git_path("%.*s", len, buffer);
+				continue;
+			}
+		}
+
+		/*
+		 * Anything else, just open it and try to use it as
+		 * a ref
+		 */
+		fd = open(path, O_RDONLY);
+		if (fd < 0)
+			return NULL;
+		len = read(fd, buffer, sizeof(buffer)-1);
 		close(fd);
-		if (len < 0)
+
+		/*
+		 * Is it a symbolic ref?
+		 */
+		if (len < 4 || memcmp("ref:", buffer, 4))
 			break;
+		buf = buffer + 4;
+		len -= 4;
+		while (len && isspace(*buf))
+			buf++, len--;
+		while (len && isspace(buf[len-1]))
+			buf[--len] = 0;
+		path = git_path("%.*s", len, buf);
+	}
+	if (len < 40 || get_sha1_hex(buffer, sha1))
+		return NULL;
+	return path;
+}
 
-		buffer[len] = 0;
-		while (len && isspace(buffer[len-1]))
-			buffer[--len] = 0;
+int create_symref(const char *git_HEAD, const char *refs_heads_master)
+{
+#if USE_SYMLINK_HEAD
+	unlink(git_HEAD);
+	return symlink(refs_heads_master, git_HEAD);
+#else
+	const char *lockpath;
+	char ref[1000];
+	int fd, len, written;
 
-		if (!strncmp(buffer, "ref:", 4)) {
-			char *buf;
-			if (depth > MAXDEPTH)
-				break;
-			depth++;
-			buf = buffer + 4;
-			len -= 4;
-			while (len && isspace(*buf))
-				buf++, len--;
-			filename = git_path("%.*s", len, buf);
-			continue;
-		}
-		if (len >= 40)
-			ret = get_sha1_hex(buffer, sha1);
-		break;
+	len = snprintf(ref, sizeof(ref), "ref: %s\n", refs_heads_master);
+	if (sizeof(ref) <= len) {
+		error("refname too long: %s", refs_heads_master);
+		return -1;
 	}
-	return ret;
+	lockpath = mkpath("%s.lock", git_HEAD);
+	fd = open(lockpath, O_CREAT | O_EXCL | O_WRONLY, 0666);	
+	written = write(fd, ref, len);
+	close(fd);
+	if (written != len) {
+		unlink(lockpath);
+		error("Unable to write to %s", lockpath);
+		return -2;
+	}
+	if (rename(lockpath, git_HEAD) < 0) {
+		unlink(lockpath);
+		error("Unable to create %s", git_HEAD);
+		return -3;
+	}
+	return 0;
+#endif
+}
+
+int read_ref(const char *filename, unsigned char *sha1)
+{
+	if (resolve_ref(filename, sha1, 1))
+		return 0;
+	return -1;
 }
 
 static int do_for_each_ref(const char *base, int (*fn)(const char *path, const unsigned char *sha1))