vim-patch:8.2.2166: auto format doesn't work when deleting text

Problem:    Auto format doesn't work when deleting text.
Solution:   Make "x" trigger auto format. (closes vim/vim#7504)
d0a1dee3f1

src/nvim/edit.c

@@ -3716,7 +3716,7 @@ static bool ins_compl_prep(int c)
         retval = true;
       }
 
-      auto_format(FALSE, TRUE);
+      auto_format(false, true);
 
       // Trigger the CompleteDonePre event to give scripts a chance to
       // act upon the completion before clearing the info, and restore
@@ -6503,7 +6503,7 @@ stop_insert (
           curwin->w_cursor = tpos;
       }
 
-      auto_format(TRUE, FALSE);
+      auto_format(true, false);
 
       if (ascii_iswhite(cc)) {
         if (gchar_cursor() != NUL)

src/nvim/ops.c

@@ -1683,6 +1683,7 @@ int op_delete(oparg_T *oap)
                      (int)oap->line_count-1, n, deleted_bytes,
                      0, 0, 0, kExtmarkUndo);
     }
+    auto_format(false, true);
   }
 
   msgmore(curbuf->b_ml.ml_line_count - old_lcount);

src/nvim/testdir/test_textformat.vim

@@ -957,6 +957,18 @@ func Test_fo_a_w()
   call assert_equal('g uu uu ', getline(1)[-8:])
   call assert_equal(['uu. foo'], getline(2, '$'))
 
+  " using backspace or "x" triggers reformat
+  call setline(1, ['1 2 3 4 5 ', '6 7 8 9'])
+  set tw=10
+  set fo=taw
+  set bs=indent,eol,start
+  exe "normal 1G4la\<BS>\<BS>\<Esc>"
+  call assert_equal(['1 2 4 5 6 ', '7 8 9'], getline(1, 2))
+  exe "normal f4xx"
+  call assert_equal(['1 2 5 6 7 ', '8 9'], getline(1, 2))
+
+  set tw=0
+  set fo&
   %bw!
 endfunc