read_index_from: remove bogus errno assignments

These assignments comes from the very first commit e83c516 (Initial
revision of "git", the information manager from hell - 2005-04-07).
Back then we did not die() when errors happened so correct errno was
required.

Since 5d1a5c0 ([PATCH] Better error reporting for "git status" -
2005-10-01), read_index_from() learned to die rather than just return
-1 and these assignments became irrelevant. Remove them.

While at it, move die_errno() next to xmmap() call because it's the
mmap's error code that we care about. Otherwise if close(fd); fails,
it could overwrite mmap's errno.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/read-cache.c b/read-cache.c
index 0a641034ce164fff91c9e8736b28cf98b6eba6bb..5a78d6b05fd87c4e2a96b294a51ba8659416c3aa 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -1274,11 +1274,9 @@ int read_index_from(struct index_state *istate, const char *path)
        void *mmap;
        size_t mmap_size;
 
-       errno = EBUSY;
        if (istate->initialized)
                return istate->cache_nr;
 
-       errno = ENOENT;
        istate->timestamp.sec = 0;
        istate->timestamp.nsec = 0;
        fd = open(path, O_RDONLY);
@@ -1291,15 +1289,14 @@ int read_index_from(struct index_state *istate, const char *path)
        if (fstat(fd, &st))
                die_errno("cannot stat the open index");
 
-       errno = EINVAL;
        mmap_size = xsize_t(st.st_size);
        if (mmap_size < sizeof(struct cache_header) + 20)
                die("index file smaller than expected");
 
        mmap = xmmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
-       close(fd);
        if (mmap == MAP_FAILED)
                die_errno("unable to map index file");
+       close(fd);
 
        hdr = mmap;
        if (verify_hdr(hdr, mmap_size) < 0)
@@ -1358,7 +1355,6 @@ int read_index_from(struct index_state *istate, const char *path)
 
 unmap:
        munmap(mmap, mmap_size);
-       errno = EINVAL;
        die("index file corrupt");
 }