push: clarify rejection of update to non-commit-ish

diff --git a/csum-file.h b/csum-file.h
index 6a7967c6bf604076c7d68ce139f65f34df3bc30e..3b540bdc21d2edf8d3d6fc2b5e52cc840aa19395 100644 (file)
--- a/csum-file.h
+++ b/csum-file.h
@@ -17,6 +17,15 @@ struct sha1file {
        unsigned char buffer[8192];
 };
 
+/* Checkpoint */
+struct sha1file_checkpoint {
+       off_t offset;
+       git_SHA_CTX ctx;
+};
+
+extern void sha1file_checkpoint(struct sha1file *, struct sha1file_checkpoint *);
+extern int sha1file_truncate(struct sha1file *, struct sha1file_checkpoint *);
+
 /* sha1close flags */
 #define CSUM_CLOSE     1
 #define CSUM_FSYNC     2