refactor: remove cpo-& behavior (#17745)

cpo-& has been removed, but its behavior was accidentally made the
default behavior. That should be removed instead.

3 files changed, 6 insertions, 10 deletions

diff --git a/src/nvim/buffer_defs.h b/src/nvim/buffer_defs.h
index f9541a55a3..29413281ad 100644
--- a/src/nvim/buffer_defs.h
+++ b/src/nvim/buffer_defs.h
@@ -90,7 +90,6 @@ typedef struct {
 #define BF_NEW_W        0x20    // Warned for BF_NEW and file created
 #define BF_READERR      0x40    // got errors while reading the file
 #define BF_DUMMY        0x80    // dummy buffer, only used internally
-#define BF_PRESERVED    0x100   // ":preserve" was used
 #define BF_SYN_SET      0x200   // 'syntax' option was set
 
 // Mask to check for flags that prevent normal writing
diff --git a/src/nvim/ex_docmd.c b/src/nvim/ex_docmd.c
index 5ef9f6c05e..dab17fc3a4 100644
--- a/src/nvim/ex_docmd.c
+++ b/src/nvim/ex_docmd.c
@@ -7155,7 +7155,6 @@ void alist_slash_adjust(void)
 /// ":preserve".
 static void ex_preserve(exarg_T *eap)
 {
-  curbuf->b_flags |= BF_PRESERVED;
   ml_preserve(curbuf, true, true);
 }
 
diff --git a/src/nvim/memline.c b/src/nvim/memline.c
index 59f57aa667..5d62ddc912 100644
--- a/src/nvim/memline.c
+++ b/src/nvim/memline.c
@@ -585,16 +585,14 @@ void ml_close(buf_T *buf, int del_file)
   buf->b_flags &= ~BF_RECOVERED;
 }
 
-/*
- * Close all existing memlines and memfiles.
- * Only used when exiting.
- * When 'del_file' is TRUE, delete the memfiles.
- * But don't delete files that were ":preserve"d when we are POSIX compatible.
- */
-void ml_close_all(int del_file)
+/// Close all existing memlines and memfiles.
+/// Only used when exiting.
+///
+/// @param del_file  if true, delete the memfiles.
+void ml_close_all(bool del_file)
 {
   FOR_ALL_BUFFERS(buf) {
-    ml_close(buf, del_file && ((buf->b_flags & BF_PRESERVED) == 0));
+    ml_close(buf, del_file);
   }
   spell_delete_wordlist();      // delete the internal wordlist
   vim_deltempdir();             // delete created temp directory