add: introduce "--renormalize"

Make it safer to normalize the line endings in a repository.
Files that had been commited with CRLF will be commited with LF.

The old way to normalize a repo was like this:

 # Make sure that there are not untracked files
 $ echo "* text=auto" >.gitattributes
 $ git read-tree --empty
 $ git add .
 $ git commit -m "Introduce end-of-line normalization"

The user must make sure that there are no untracked files,
otherwise they would have been added and tracked from now on.

The new "add --renormalize" does not add untracked files:

 $ echo "* text=auto" >.gitattributes
 $ git add --renormalize .
 $ git commit -m "Introduce end-of-line normalization"

Note that "git add --renormalize <pathspec>" is the short form for
"git add -u --renormalize <pathspec>".

While at it, document that the same renormalization may be needed,
whenever a clean filter is added or changed.

Helped-By: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Torsten Bögershausen <tboegi@web.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 14 insertions, 2 deletions

diff --git a/sha1_file.c b/sha1_file.c
index 10c3a00..15abb18 100644
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -74,6 +74,18 @@ static struct cached_object *find_cached_object(const unsigned char *sha1)
 	return NULL;
 }
 
+
+static enum safe_crlf get_safe_crlf(unsigned flags)
+{
+	if (flags & HASH_RENORMALIZE)
+		return SAFE_CRLF_RENORMALIZE;
+	else if (flags & HASH_WRITE_OBJECT)
+		return safe_crlf;
+	else
+		return SAFE_CRLF_FALSE;
+}
+
+
 int mkdir_in_gitdir(const char *path)
 {
 	if (mkdir(path, 0777)) {
@@ -1680,7 +1692,7 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size,
 	if ((type == OBJ_BLOB) && path) {
 		struct strbuf nbuf = STRBUF_INIT;
 		if (convert_to_git(&the_index, path, buf, size, &nbuf,
-				   write_object ? safe_crlf : SAFE_CRLF_FALSE)) {
+				   get_safe_crlf(flags))) {
 			buf = strbuf_detach(&nbuf, &size);
 			re_allocated = 1;
 		}
@@ -1714,7 +1726,7 @@ static int index_stream_convert_blob(unsigned char *sha1, int fd,
 	assert(would_convert_to_git_filter_fd(path));
 
 	convert_to_git_filter_fd(&the_index, path, fd, &sbuf,
-				 write_object ? safe_crlf : SAFE_CRLF_FALSE);
+				 get_safe_crlf(flags));
 
 	if (write_object)
 		ret = write_sha1_file(sbuf.buf, sbuf.len, typename(OBJ_BLOB),