vim-patch:8.1.0470: pointer ownership around fname_expand() is unclear

Problem:    Pointer ownership around fname_expand() is unclear.
Solution:   Allow b_ffname and b_sfname to point to the same allocated memory,
            only free one.  Update comments.
https://github.com/vim/vim/commit/3d6014f0336d9a64c01a7518fe45fde0a925fa20

1 files changed, 5 insertions, 3 deletions

diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index 44a9b39939..cc09b7e989 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -533,9 +533,11 @@ struct file_buffer {
   // b_fname    is the same as b_sfname, unless ":cd" has been done,
   //            then it is the same as b_ffname (NULL for no name).
   //
-  char_u      *b_ffname;        // full path file name
-  char_u      *b_sfname;        // short file name
-  char_u      *b_fname;         // current file name
+  char_u      *b_ffname;        // full path file name, allocated
+  char_u      *b_sfname;        // short file name, allocated, may be equal to
+                                // b_ffname
+  char_u      *b_fname;         // current file name, points to b_ffname or
+                                // b_sfname
 
   bool file_id_valid;
   FileID file_id;