git am: Display some help text when patch is empty

diff --git a/merge-file.c b/merge-file.c
index 07cc0c9053b7784249e2e34f90ac6e64c878a66e..c336c93c01c0bad76d6189065f0e6630d0b7f5af 100644 (file)
--- a/merge-file.c
+++ b/merge-file.c
@@ -30,6 +30,12 @@ static void *three_way_filemerge(const char *path, mmfile_t *base, mmfile_t *our
        int merge_status;
        mmbuffer_t res;
 
+       /*
+        * This function is only used by cmd_merge_tree, which
+        * does not respect the merge.conflictstyle option.
+        * There is no need to worry about a label for the
+        * common ancestor.
+        */
        merge_status = ll_merge(&res, path, base, NULL,
                                our, ".our", their, ".their", 0);
        if (merge_status < 0)