Make AutoCRLF ternary variable.

This allows you to do:

	[core]
		AutoCRLF = input

and it should do only the CRLF->LF translation (ie it simplifies CRLF only
when reading working tree files, but when checking out files, it leaves
the LF alone, and doesn't turn it into a CRLF).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

config.c

@@ -325,6 +325,10 @@ int git_default_config(const char *var, const char *value)
 	}
 
 	if (!strcmp(var, "core.autocrlf")) {
+		if (value && !strcasecmp(value, "input")) {
+			auto_crlf = -1;
+			return 0;
+		}
 		auto_crlf = git_config_bool(var, value);
 		return 0;
 	}

convert.c

@@ -140,7 +140,7 @@ int convert_to_working_tree(const char *path, char **bufp, unsigned long *sizep)
 	 * based on filename patterns. Right now we just do the
 	 * stupid auto-CRLF one.
 	 */
-	if (!auto_crlf)
+	if (auto_crlf <= 0)
 		return 0;
 
 	size = *sizep;

environment.c

@@ -28,7 +28,7 @@ size_t packed_git_window_size = DEFAULT_PACKED_GIT_WINDOW_SIZE;
 size_t packed_git_limit = DEFAULT_PACKED_GIT_LIMIT;
 int pager_in_use;
 int pager_use_color = 1;
-int auto_crlf = 0;
+int auto_crlf = 0;	/* 1: both ways, -1: only when adding git objects */
 
 static const char *git_dir;
 static char *git_object_dir, *git_index_file, *git_refs_dir, *git_graft_file;