* fileio.c (Fwrite_region, Fdo_auto_save): Handle save_length = -2.

(Fset_buffer_auto_saved): Handle save_length = -2.

Comment changes in other files.

1 files changed, 13 insertions, 7 deletions

diff --git a/src/fileio.c b/src/fileio.c
index bf96b3aa2b1..43872d59472 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -4492,7 +4492,8 @@ This calls `write-region-annotate-functions' at the start, and
       if (visiting)
         {
           SAVE_MODIFF = MODIFF;
-          XSETFASTINT (current_buffer->save_length, Z - BEG);
+          if (XINT (current_buffer->save_length) != -2)
+            XSETFASTINT (current_buffer->save_length, Z - BEG);
           current_buffer->filename = visit_file;
         }
       UNGCPRO;
@@ -4703,7 +4704,8 @@ This calls `write-region-annotate-functions' at the start, and
   if (visiting)
     {
       SAVE_MODIFF = MODIFF;
-      XSETFASTINT (current_buffer->save_length, Z - BEG);
+      if (XINT (current_buffer->save_length) != -2)
+        XSETFASTINT (current_buffer->save_length, Z - BEG);
       current_buffer->filename = visit_file;
       update_mode_lines++;
     }
@@ -5307,7 +5309,7 @@ A non-nil CURRENT-ONLY argument means save only current buffer.  */)
             && BUF_SAVE_MODIFF (b) < BUF_MODIFF (b)
             && b->auto_save_modified < BUF_MODIFF (b)
             /* -1 means we've turned off autosaving for a while--see below.  */
-            && XINT (b->save_length) >= 0
+            && XINT (b->save_length) != -1
             && (do_handled_files
                 || NILP (Ffind_file_name_handler (b->auto_save_file_name,
                                                   Qwrite_region))))
@@ -5321,8 +5323,10 @@ A non-nil CURRENT-ONLY argument means save only current buffer.  */)
                 && EMACS_SECS (before_time) - b->auto_save_failure_time < 1200)
               continue;
 
-            if ((XFASTINT (b->save_length) * 10
-                 > (BUF_Z (b) - BUF_BEG (b)) * 13)
+            if (XINT (b->save_length) != -2
+                /* -2 is a magic flag turning off this feature in a buffer.  */
+                && (XFASTINT (b->save_length) * 10
+                    > (BUF_Z (b) - BUF_BEG (b)) * 13)
                 /* A short file is likely to change a large fraction;
                    spare the user annoying messages.  */
                 && XFASTINT (b->save_length) > 5000
@@ -5347,7 +5351,8 @@ A non-nil CURRENT-ONLY argument means save only current buffer.  */)
             internal_condition_case (auto_save_1, Qt, auto_save_error);
             auto_saved++;
             b->auto_save_modified = BUF_MODIFF (b);
-            XSETFASTINT (current_buffer->save_length, Z - BEG);
+            if (XINT (current_buffer->save_length) != -2)
+              XSETFASTINT (current_buffer->save_length, Z - BEG);
             set_buffer_internal (old);
 
             EMACS_GET_TIME (after_time);
@@ -5392,7 +5397,8 @@ No auto-save file will be written until the buffer changes again.  */)
      ()
 {
   current_buffer->auto_save_modified = MODIFF;
-  XSETFASTINT (current_buffer->save_length, Z - BEG);
+  if (XINT (current_buffer->save_length) != -2)
+    XSETFASTINT (current_buffer->save_length, Z - BEG);
   current_buffer->auto_save_failure_time = -1;
   return Qnil;
 }