[PATCH 1/4] strbuf.c: keep errno in strbuf_read_file()

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This function is used to replaced some code in the next patch that
does this (i.e. keep the errno when read() fails)

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 strbuf.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/strbuf.c b/strbuf.c
index 33018d8..61d685d 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -454,15 +454,18 @@ int strbuf_getwholeline_fd(struct strbuf *sb, int fd, int term)
 
 int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 {
-	int fd, len;
+	int fd, len, saved_errno;
 
 	fd = open(path, O_RDONLY);
 	if (fd < 0)
 		return -1;
 	len = strbuf_read(sb, fd, hint);
+	saved_errno = errno;
 	close(fd);
-	if (len < 0)
+	if (len < 0) {
+		errno = saved_errno;
 		return -1;
+	}
 
 	return len;
 }
-- 
1.9.1.346.ga2b5940