vim-patch:9.0.0816: CTRL-Z at end of file is always dropped

Problem:    CTRL-Z at end of file is always dropped.
Solution:   Add the 'endoffile' option, like the 'endofline' option.
            (closes vim/vim#11408, closes vim/vim#11397)

Cherry-pick test_fixeol.vim changes from patch 8.2.1432.
Cherry-pick 'endoffile' changes from latest Vim runtime update.

fb0cf2357e

vim-patch:f0b567e32a46

Revert unintended Makefile change

f0b567e32a

vim-patch:72c8e3c070b3

Fix wrong struct access for member.

72c8e3c070

vim-patch:3f68a4136eb9

Add missing entry for the 'endoffile' option.

3f68a4136e

Co-authored-by: Bram Moolenaar <Bram@vim.org>

runtime/doc/options.txt

@@ -2135,6 +2135,15 @@ A jump table for the options with a short description can be found at |Q_op|.
 
 	See 'fileencoding' to control file-content encoding.
 
+			*'endoffile'* *'eof'* *'noendoffile'* *'noeof'*
+'endoffile' 'eof'	boolean	(default on)
+			local to buffer
+	Indicates that a CTRL-Z character was found at the end of the file
+	when reading it.  Normally only happens when 'fileformat' is "dos".
+	When writing a file and this option is off and the 'binary' option
+	is on, or 'fixeol' option is off, no CTRL-Z will be written at the
+	end of the file.
+
 			*'endofline'* *'eol'* *'noendofline'* *'noeol'*
 'endofline' 'eol'	boolean	(default on)
 			local to buffer
@@ -2490,7 +2499,7 @@ A jump table for the options with a short description can be found at |Q_op|.
 'fixendofline' 'fixeol'	boolean	(default on)
 			local to buffer
 	When writing a file and this option is on, <EOL> at the end of file
-	will be restored if missing. Turn this option off if you want to
+	will be restored if missing.  Turn this option off if you want to
 	preserve the situation from the original file.
 	When the 'binary' option is set the value of this option doesn't
 	matter.

runtime/doc/quickref.txt

@@ -689,6 +689,7 @@ Short explanation of each option:		*option-list*
 'display'	  'dy'	    list of flags for how to display text
 'eadirection'	  'ead'     in which direction 'equalalways' works
 'encoding'	  'enc'     encoding used internally
+'endoffile'	  'eof'     write CTRL-Z at end of the file
 'endofline'	  'eol'     write <EOL> for last line in file
 'equalalways'	  'ea'	    windows are automatically made the same size
 'equalprg'	  'ep'	    external program to use for "=" command

runtime/optwin.vim

@@ -1,7 +1,7 @@
 " These commands create the option window.
 "
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
-" Last Change:	2022 Oct 15
+" Last Change:	2022 Oct 28
 
 " If there already is an option window, jump to that one.
 let buf = bufnr('option-window')
@@ -956,6 +956,9 @@ call <SID>BinOptionL("bin")
 call <SID>AddOption("endofline", gettext("last line in the file has an end-of-line"))
 call append("$", "\t" .. s:local_to_buffer)
 call <SID>BinOptionL("eol")
+call <SID>AddOption("endoffile", gettext("last line in the file followed by CTRL-Z"))
+call append("$", "\t" .. s:local_to_buffer)
+call <SID>BinOptionL("eof")
 call <SID>AddOption("fixendofline", gettext("fixes missing end-of-line at end of text file"))
 call append("$", "\t" .. s:local_to_buffer)
 call <SID>BinOptionL("fixeol")

src/nvim/buffer_defs.h

@@ -675,6 +675,7 @@ struct file_buffer {
   char *b_p_cfu;                ///< 'completefunc'
   char *b_p_ofu;                ///< 'omnifunc'
   char *b_p_tfu;                ///< 'tagfunc'
+  int b_p_eof;                  ///< 'endoffile'
   int b_p_eol;                  ///< 'endofline'
   int b_p_fixeol;               ///< 'fixendofline'
   int b_p_et;                   ///< 'expandtab'

src/nvim/fileio.c

@@ -525,6 +525,7 @@ int readfile(char *fname, char *sfname, linenr_T from, linenr_T lines_to_skip,
     // correctly set when reading stdin.
     if (!read_buffer) {
       curbuf->b_p_eol = true;
+      curbuf->b_p_eof = false;
       curbuf->b_start_eol = true;
     }
     curbuf->b_p_bomb = false;
@@ -1629,12 +1630,13 @@ failed:
       && !got_int
       && linerest != 0
       && !(!curbuf->b_p_bin
-           && fileformat == EOL_DOS
-           && *line_start == Ctrl_Z
-           && ptr == line_start + 1)) {
+           && fileformat == EOL_DOS)) {
     // remember for when writing
     if (set_options) {
       curbuf->b_p_eol = false;
+      if (*line_start == Ctrl_Z && ptr == line_start + 1) {
+        curbuf->b_p_eof = false;
+      }
     }
     *ptr = NUL;
     len = (colnr_T)(ptr - line_start + 1);
@@ -3191,6 +3193,11 @@ restore_backup:
         len = 0;
         write_info.bw_start_lnum = lnum;
       }
+      if (!buf->b_p_fixeol && buf->b_p_eof) {
+        // write trailing CTRL-Z
+        (void)write_eintr(write_info.bw_fd, "\x1a", 1);
+      }
+
       // write failed or last line has no EOL: stop here
       if (end == 0
           || (lnum == end

src/nvim/option.c

@@ -3978,6 +3978,8 @@ static char_u *get_varp(vimoption_T *p)
     return (char_u *)&(curbuf->b_p_cfu);
   case PV_OFU:
     return (char_u *)&(curbuf->b_p_ofu);
+  case PV_EOF:
+    return (char_u *)&(curbuf->b_p_eof);
   case PV_EOL:
     return (char_u *)&(curbuf->b_p_eol);
   case PV_FIXEOL:

src/nvim/option_defs.h

@@ -497,6 +497,7 @@ EXTERN char_u *p_ef;            // 'errorfile'
 EXTERN char *p_efm;             // 'errorformat'
 EXTERN char *p_gefm;            // 'grepformat'
 EXTERN char *p_gp;              // 'grepprg'
+EXTERN int p_eof;               ///< 'endoffile'
 EXTERN int p_eol;               ///< 'endofline'
 EXTERN char *p_ei;              // 'eventignore'
 EXTERN int p_et;                ///< 'expandtab'
@@ -858,6 +859,7 @@ enum {
   BV_CFU,
   BV_DEF,
   BV_INC,
+  BV_EOF,
   BV_EOL,
   BV_FIXEOL,
   BV_EP,

src/nvim/options.lua

@@ -640,6 +640,15 @@ return {
       varname='p_enc',
       defaults={if_true=macros('ENC_DFLT')}
     },
+    {
+      full_name='endoffile', abbreviation='eof',
+      short_desc=N_("write CTRL-Z for last line in file"),
+      type='bool', scope={'buffer'},
+      no_mkrc=true,
+      redraw={'statuslines'},
+      varname='p_eof',
+      defaults={if_true=true}
+    },
     {
       full_name='endofline', abbreviation='eol',
       short_desc=N_("write <EOL> for last line in file"),

src/nvim/testdir/test_fixeol.vim

@@ -1,16 +1,17 @@
-" Tests for 'fixeol' and 'eol'
+" Tests for 'fixeol', 'eof' and 'eol'
+
 func Test_fixeol()
   " first write two test files – with and without trailing EOL
   " use Unix fileformat for consistency
   set ff=unix
   enew!
-  call setline('.', 'with eol')
+  call setline('.', 'with eol or eof')
   w! XXEol
   enew!
-  set noeol nofixeol
-  call setline('.', 'without eol')
+  set noeof noeol nofixeol
+  call setline('.', 'without eol or eof')
   w! XXNoEol
-  set eol fixeol
+  set eol eof fixeol
   bwipe XXEol XXNoEol
 
   " try editing files with 'fixeol' disabled
@@ -43,6 +44,8 @@ func Test_fixeol()
   call delete('XXNoEol')
   call delete('XXTestEol')
   call delete('XXTestNoEol')
-  set ff& fixeol& eol&
+  set ff& fixeol& eof& eol&
   enew!
 endfunc
+
+" vim: shiftwidth=2 sts=2 expandtab