git: --no-lazy-fetch option

Sometimes, especially during tests of low level machinery, it is
handy to have a way to disable lazy fetching of objects.  This
allows us to say, for example, "git cat-file -e <object-name>", to
see if the object is locally available.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

git.c

@@ -4,6 +4,7 @@
 #include "exec-cmd.h"
 #include "gettext.h"
 #include "help.h"
+#include "object-file.h"
 #include "pager.h"
 #include "read-cache-ll.h"
 #include "run-command.h"
@@ -186,6 +187,8 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
 			use_pager = 0;
 			if (envchanged)
 				*envchanged = 1;
+		} else if (!strcmp(cmd, "--no-lazy-fetch")) {
+			fetch_if_missing = 0;
 		} else if (!strcmp(cmd, "--no-replace-objects")) {
 			disable_replace_refs();
 			setenv(NO_REPLACE_OBJECTS_ENVIRONMENT, "1", 1);