Merge branch 'jk/diff-no-rename-empty'

Forbids rename detection logic from matching two empty files as renames
during merge-recursive to prevent mismerges.

By Jeff King
* jk/diff-no-rename-empty:
  merge-recursive: don't detect renames of empty files
  teach diffcore-rename to optionally ignore empty content
  make is_empty_blob_sha1 available everywhere
  drop casts from users EMPTY_TREE_SHA1_BIN

1 files changed, 13 insertions, 0 deletions

diff --git a/cache.h b/cache.h
index a8aceb5aee..806bf2b76f 100644
--- a/cache.h
+++ b/cache.h
@@ -708,6 +708,19 @@ static inline void hashclr(unsigned char *hash)
 #define EMPTY_TREE_SHA1_BIN \
 	 ((const unsigned char *) EMPTY_TREE_SHA1_BIN_LITERAL)
 
+#define EMPTY_BLOB_SHA1_HEX \
+	"e69de29bb2d1d6434b8b29ae775ad8c2e48c5391"
+#define EMPTY_BLOB_SHA1_BIN_LITERAL \
+	"\xe6\x9d\xe2\x9b\xb2\xd1\xd6\x43\x4b\x8b" \
+	"\x29\xae\x77\x5a\xd8\xc2\xe4\x8c\x53\x91"
+#define EMPTY_BLOB_SHA1_BIN \
+	((const unsigned char *) EMPTY_BLOB_SHA1_BIN_LITERAL)
+
+static inline int is_empty_blob_sha1(const unsigned char *sha1)
+{
+	return !hashcmp(sha1, EMPTY_BLOB_SHA1_BIN);
+}
+
 int git_mkstemp(char *path, size_t n, const char *template);
 
 int git_mkstemps(char *path, size_t n, const char *template, int suffix_len);