abspath: convert absolute_path() to strbuf

Move most of the code of absolute_path() into the new function
strbuf_add_absolute_path() and in the process transform it to use
struct strbuf and xgetcwd() instead of a PATH_MAX-sized buffer,
which can be too small on some file systems.

Signed-off-by: Rene Scharfe <l.s.r@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/strbuf.c b/strbuf.c
index f3af203ec7..bf4c31b157 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -568,6 +568,31 @@ void strbuf_humanise_bytes(struct strbuf *buf, off_t bytes)
 	}
 }
 
+void strbuf_add_absolute_path(struct strbuf *sb, const char *path)
+{
+	if (!*path)
+		die("The empty string is not a valid path");
+	if (!is_absolute_path(path)) {
+		struct stat cwd_stat, pwd_stat;
+		size_t orig_len = sb->len;
+		char *cwd = xgetcwd();
+		char *pwd = getenv("PWD");
+		if (pwd && strcmp(pwd, cwd) &&
+		    !stat(cwd, &cwd_stat) &&
+		    (cwd_stat.st_dev || cwd_stat.st_ino) &&
+		    !stat(pwd, &pwd_stat) &&
+		    pwd_stat.st_dev == cwd_stat.st_dev &&
+		    pwd_stat.st_ino == cwd_stat.st_ino)
+			strbuf_addstr(sb, pwd);
+		else
+			strbuf_addstr(sb, cwd);
+		if (sb->len > orig_len && !is_dir_sep(sb->buf[sb->len - 1]))
+			strbuf_addch(sb, '/');
+		free(cwd);
+	}
+	strbuf_addstr(sb, path);
+}
+
 int printf_ln(const char *fmt, ...)
 {
 	int ret;