Use nonrelative paths instead of absolute paths for cloned repositories

Particularly for the "alternates" file, if one will be created, we
want a path that doesn't depend on the current directory, but we want
to retain any symlinks in the path as given and any in the user's view
of the current directory when the path was given.

Signed-off-by: Daniel Barkalow <barkalow@iabervon.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 36 insertions, 0 deletions

diff --git a/path.c b/path.c
index b7c24a2aac..4945f2abc5 100644
--- a/path.c
+++ b/path.c
@@ -291,6 +291,42 @@ int adjust_shared_perm(const char *path)
 	return 0;
 }
 
+static const char *get_pwd_cwd(void)
+{
+	static char cwd[PATH_MAX + 1];
+	char *pwd;
+	struct stat cwd_stat, pwd_stat;
+	if (getcwd(cwd, PATH_MAX) == NULL)
+		return NULL;
+	pwd = getenv("PWD");
+	if (pwd && strcmp(pwd, cwd)) {
+		stat(cwd, &cwd_stat);
+		if (!stat(pwd, &pwd_stat) &&
+		    pwd_stat.st_dev == cwd_stat.st_dev &&
+		    pwd_stat.st_ino == cwd_stat.st_ino) {
+			strlcpy(cwd, pwd, PATH_MAX);
+		}
+	}
+	return cwd;
+}
+
+const char *make_nonrelative_path(const char *path)
+{
+	static char buf[PATH_MAX + 1];
+
+	if (path[0] == '/') {
+		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
+			die ("Too long path: %.*s", 60, path);
+	} else {
+		const char *cwd = get_pwd_cwd();
+		if (!cwd)
+			die("Cannot determine the current working directory");
+		if (snprintf(buf, PATH_MAX, "%s/%s", cwd, path) >= PATH_MAX)
+			die ("Too long path: %.*s", 60, path);
+	}
+	return buf;
+}
+
 /* We allow "recursive" symbolic links. Only within reason, though. */
 #define MAXDEPTH 5