git-read-tree --index-output=<file>

This corrects the interface mistake of the previous one, and
gives a command line parameter to the only plumbing command that
currently needs it: "git-read-tree".

We can add the calls to set_alternate_index_output() to other
plumbing commands that update the index if/when needed.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 8 insertions, 3 deletions

diff --git a/lockfile.c b/lockfile.c
index 2023ebb..bed6b21 100644
--- a/lockfile.c
+++ b/lockfile.c
@@ -4,6 +4,7 @@
 #include "cache.h"
 
 static struct lock_file *lock_file_list;
+static const char *alternate_index_output;
 
 static void remove_lock_file(void)
 {
@@ -70,11 +71,15 @@ int hold_locked_index(struct lock_file *lk, int die_on_error)
 	return hold_lock_file_for_update(lk, get_index_file(), die_on_error);
 }
 
+void set_alternate_index_output(const char *name)
+{
+	alternate_index_output = name;
+}
+
 int commit_locked_index(struct lock_file *lk)
 {
-	char *output = getenv(INDEX_OUTPUT_ENVIRONMENT);
-	if (output && *output) {
-		int result = rename(lk->filename, output);
+	if (alternate_index_output) {
+		int result = rename(lk->filename, alternate_index_output);
 		lk->filename[0] = 0;
 		return result;
 	}