git-am: cope better with an empty Subject: line

diff --git a/builtin-merge-file.c b/builtin-merge-file.c
index 58deb62ac08507901c40e89aec0cea7fcdc78f1e..baff4495f0a4cbe6e5cf94975110e6ddd5518c20 100644 (file)
--- a/builtin-merge-file.c
+++ b/builtin-merge-file.c
@@ -57,7 +57,8 @@ int cmd_merge_file(int argc, const char **argv, const char *prefix)
 
                if (!f)
                        ret = error("Could not open %s for writing", filename);
-               else if (fwrite(result.ptr, result.size, 1, f) != 1)
+               else if (result.size &&
+                        fwrite(result.ptr, result.size, 1, f) != 1)
                        ret = error("Could not write to %s", filename);
                else if (fclose(f))
                        ret = error("Could not close %s", filename);