vim-patch:7.4.2251

Problem:    In rare cases diffing 4 buffers is not enough.
Solution:   Raise the limit to 8. (closes vim/vim#1000)

015efc32c1

src/nvim/buffer_defs.h

@@ -771,7 +771,7 @@ struct file_buffer {
 /*
  * Stuff for diff mode.
  */
-# define DB_COUNT 4     /* up to four buffers can be diff'ed */
+# define DB_COUNT 8     /* up to four buffers can be diff'ed */
 
 /*
  * Each diffblock defines where a block of lines starts in each of the buffers