patch 8.1.2302: :lockmarks does not work for '[ and ']v8.1.2302

Problem:    :lockmarks does not work for '[ and '].
Solution:   save and restore '[ and '] marks. (James McCoy, closes #5222)

10 files changed, 208 insertions, 69 deletions

diff --git a/src/bufwrite.c b/src/bufwrite.c
index 13091a336e..8393df1a0c 100644
--- a/src/bufwrite.c
+++ b/src/bufwrite.c
@@ -683,6 +683,8 @@ buf_write(
     context_sha256_T sha_ctx;
 #endif
     unsigned int    bkc = get_bkc_value(buf);
+    pos_T	    orig_start = buf->b_op_start;
+    pos_T	    orig_end = buf->b_op_end;
 
     if (fname == NULL || *fname == NUL)	// safety check
 	return FAIL;
@@ -875,6 +877,13 @@ buf_write(
 #endif
 				       )
 	{
+	    if (buf != NULL && cmdmod.lockmarks)
+	    {
+		// restore the original '[ and '] positions
+		buf->b_op_start = orig_start;
+		buf->b_op_end = orig_end;
+	    }
+
 	    --no_wait_return;
 	    msg_scroll = msg_save;
 	    if (nofile_err)
@@ -952,6 +961,13 @@ buf_write(
 	    fname = buf->b_sfname;
     }
 
+    if (cmdmod.lockmarks)
+    {
+	// restore the original '[ and '] positions
+	buf->b_op_start = orig_start;
+	buf->b_op_end = orig_end;
+    }
+
 #ifdef FEAT_NETBEANS_INTG
     if (netbeans_active() && isNetbeansBuffer(buf))
     {
diff --git a/src/diff.c b/src/diff.c
index b16f7b6f3e..dd5fb22f40 100644
--- a/src/diff.c
+++ b/src/diff.c
@@ -772,6 +772,7 @@ diff_write(buf_T *buf, diffin_T *din)
 {
     int		r;
     char_u	*save_ff;
+    int		save_lockmarks;
 
     if (din->din_fname == NULL)
 	return diff_write_buffer(buf, din);
@@ -779,9 +780,14 @@ diff_write(buf_T *buf, diffin_T *din)
     // Always use 'fileformat' set to "unix".
     save_ff = buf->b_p_ff;
     buf->b_p_ff = vim_strsave((char_u *)FF_UNIX);
+    save_lockmarks = cmdmod.lockmarks;
+    // Writing the buffer is an implementation detail of performing the diff,
+    // so it shouldn't update the '[ and '] marks.
+    cmdmod.lockmarks = TRUE;
     r = buf_write(buf, din->din_fname, NULL,
 			(linenr_T)1, buf->b_ml.ml_line_count,
 			NULL, FALSE, FALSE, FALSE, TRUE);
+    cmdmod.lockmarks = save_lockmarks;
     free_string_option(buf->b_p_ff);
     buf->b_p_ff = save_ff;
     return r;
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index c15bbc5f4c..5615adcaa5 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -749,8 +749,11 @@ do_move(linenr_T line1, linenr_T line2, linenr_T dest)
 		foldMoveRange(&win->w_folds, line1, line2, dest);
 	}
 #endif
-	curbuf->b_op_start.lnum = dest - num_lines + 1;
-	curbuf->b_op_end.lnum = dest;
+	if (!cmdmod.lockmarks)
+	{
+	    curbuf->b_op_start.lnum = dest - num_lines + 1;
+	    curbuf->b_op_end.lnum = dest;
+	}
     }
     else
     {
@@ -761,10 +764,14 @@ do_move(linenr_T line1, linenr_T line2, linenr_T dest)
 		foldMoveRange(&win->w_folds, dest + 1, line1 - 1, line2);
 	}
 #endif
-	curbuf->b_op_start.lnum = dest + 1;
-	curbuf->b_op_end.lnum = dest + num_lines;
+	if (!cmdmod.lockmarks)
+	{
+	    curbuf->b_op_start.lnum = dest + 1;
+	    curbuf->b_op_end.lnum = dest + num_lines;
+	}
     }
-    curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
+    if (!cmdmod.lockmarks)
+	curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
     mark_adjust_nofold(last_line - num_lines + 1, last_line,
 					     -(last_line - dest - extra), 0L);
 
@@ -813,9 +820,12 @@ ex_copy(linenr_T line1, linenr_T line2, linenr_T n)
     char_u	*p;
 
     count = line2 - line1 + 1;
-    curbuf->b_op_start.lnum = n + 1;
-    curbuf->b_op_end.lnum = n + count;
-    curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
+    if (!cmdmod.lockmarks)
+    {
+	curbuf->b_op_start.lnum = n + 1;
+	curbuf->b_op_end.lnum = n + count;
+	curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
+    }
 
     /*
      * there are three situations:
@@ -1055,10 +1065,17 @@ do_filter(
     char_u	*cmd_buf;
     buf_T	*old_curbuf = curbuf;
     int		shell_flags = 0;
+    pos_T	orig_start = curbuf->b_op_start;
+    pos_T	orig_end = curbuf->b_op_end;
+    int		save_lockmarks = cmdmod.lockmarks;
 
     if (*cmd == NUL)	    /* no filter command */
 	return;
 
+    // Temporarily disable lockmarks since that's needed to propagate changed
+    // regions of the buffer for foldUpdate(), linecount, etc.
+    cmdmod.lockmarks = 0;
+
     cursor_save = curwin->w_cursor;
     linecount = line2 - line1 + 1;
     curwin->w_cursor.lnum = line1;
@@ -1287,11 +1304,18 @@ error:
 
 filterend:
 
+    cmdmod.lockmarks = save_lockmarks;
     if (curbuf != old_curbuf)
     {
 	--no_wait_return;
 	emsg(_("E135: *Filter* Autocommands must not change current buffer"));
     }
+    else if (cmdmod.lockmarks)
+    {
+	curbuf->b_op_start = orig_start;
+	curbuf->b_op_end = orig_end;
+    }
+
     if (itmp != NULL)
 	mch_remove(itmp);
     if (otmp != NULL)
@@ -3276,13 +3300,16 @@ ex_append(exarg_T *eap)
      * eap->line2 pointed to the end of the buffer and nothing was appended)
      * "end" is set to lnum when something has been appended, otherwise
      * it is the same than "start"  -- Acevedo */
-    curbuf->b_op_start.lnum = (eap->line2 < curbuf->b_ml.ml_line_count) ?
-	eap->line2 + 1 : curbuf->b_ml.ml_line_count;
-    if (eap->cmdidx != CMD_append)
-	--curbuf->b_op_start.lnum;
-    curbuf->b_op_end.lnum = (eap->line2 < lnum)
-					     ? lnum : curbuf->b_op_start.lnum;
-    curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
+    if (!cmdmod.lockmarks)
+    {
+	curbuf->b_op_start.lnum = (eap->line2 < curbuf->b_ml.ml_line_count) ?
+	    eap->line2 + 1 : curbuf->b_ml.ml_line_count;
+	if (eap->cmdidx != CMD_append)
+	    --curbuf->b_op_start.lnum;
+	curbuf->b_op_end.lnum = (eap->line2 < lnum)
+						 ? lnum : curbuf->b_op_start.lnum;
+	curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
+    }
     curwin->w_cursor.lnum = lnum;
     check_cursor_lnum();
     beginline(BL_SOL | BL_FIX);
@@ -4592,10 +4619,13 @@ outofmem:
 
     if (sub_nsubs > start_nsubs)
     {
-	/* Set the '[ and '] marks. */
-	curbuf->b_op_start.lnum = eap->line1;
-	curbuf->b_op_end.lnum = line2;
-	curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
+	if (!cmdmod.lockmarks)
+	{
+	    // Set the '[ and '] marks.
+	    curbuf->b_op_start.lnum = eap->line1;
+	    curbuf->b_op_end.lnum = line2;
+	    curbuf->b_op_start.col = curbuf->b_op_end.col = 0;
+	}
 
 	if (!global_busy)
 	{
diff --git a/src/fileio.c b/src/fileio.c
index 0c2238be6b..85c5e6827f 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -188,6 +188,7 @@ readfile(
 					   wasn't possible */
     char_u	conv_rest[CONV_RESTLEN];
     int		conv_restlen = 0;	/* nr of bytes in conv_rest[] */
+    pos_T	orig_start;
     buf_T	*old_curbuf;
     char_u	*old_b_ffname;
     char_u	*old_b_fname;
@@ -250,9 +251,7 @@ readfile(
      */
     if (!filtering && !read_stdin && !read_buffer)
     {
-	pos_T	    pos;
-
-	pos = curbuf->b_op_start;
+	orig_start = curbuf->b_op_start;
 
 	/* Set '[ mark to the line above where the lines go (line 1 if zero). */
 	curbuf->b_op_start.lnum = ((from == 0) ? 1 : from);
@@ -276,7 +275,7 @@ readfile(
 	    return OK;
 #endif
 
-	curbuf->b_op_start = pos;
+	curbuf->b_op_start = orig_start;
     }
 
     if ((shortmess(SHM_OVER) || curbuf->b_help) && p_verbose == 0)
@@ -617,6 +616,7 @@ readfile(
     /*
      * Set '[ mark to the line above where the lines go (line 1 if zero).
      */
+    orig_start = curbuf->b_op_start;
     curbuf->b_op_start.lnum = ((from == 0) ? 1 : from);
     curbuf->b_op_start.col = 0;
 
@@ -658,6 +658,7 @@ readfile(
 	try_mac = (vim_strchr(p_ffs, 'm') != NULL);
 	try_dos = (vim_strchr(p_ffs, 'd') != NULL);
 	try_unix = (vim_strchr(p_ffs, 'x') != NULL);
+	curbuf->b_op_start = orig_start;
 
 	if (msg_scrolled == n)
 	    msg_scroll = m;
@@ -2471,13 +2472,14 @@ failed:
 	check_cursor_lnum();
 	beginline(BL_WHITE | BL_FIX);	    /* on first non-blank */
 
-	/*
-	 * Set '[ and '] marks to the newly read lines.
-	 */
-	curbuf->b_op_start.lnum = from + 1;
-	curbuf->b_op_start.col = 0;
-	curbuf->b_op_end.lnum = from + linecnt;
-	curbuf->b_op_end.col = 0;
+	if (!cmdmod.lockmarks)
+	{
+	    // Set '[ and '] marks to the newly read lines.
+	    curbuf->b_op_start.lnum = from + 1;
+	    curbuf->b_op_start.col = 0;
+	    curbuf->b_op_end.lnum = from + linecnt;
+	    curbuf->b_op_end.col = 0;
+	}
 
 #ifdef MSWIN
 	/*
diff --git a/src/indent.c b/src/indent.c
index 755c3a9e44..8d574c8a71 100644
--- a/src/indent.c
+++ b/src/indent.c
@@ -1001,9 +1001,12 @@ op_reindent(oparg_T *oap, int (*how)(void))
 	smsg(NGETTEXT("%ld line indented ",
 						 "%ld lines indented ", i), i);
     }
-    // set '[ and '] marks
-    curbuf->b_op_start = oap->start;
-    curbuf->b_op_end = oap->end;
+    if (!cmdmod.lockmarks)
+    {
+	// set '[ and '] marks
+	curbuf->b_op_start = oap->start;
+	curbuf->b_op_end = oap->end;
+    }
 }
 #endif // defined(FEAT_LISP) || defined(FEAT_CINDENT)
 
diff --git a/src/ops.c b/src/ops.c
index 258b27173b..b2827b263c 100644
--- a/src/ops.c
+++ b/src/ops.c
@@ -206,14 +206,15 @@ op_shift(oparg_T *oap, int curs_top, int amount)
 	msg((char *)IObuff);
     }
 
-    /*
-     * Set "'[" and "']" marks.
-     */
-    curbuf->b_op_start = oap->start;
-    curbuf->b_op_end.lnum = oap->end.lnum;
-    curbuf->b_op_end.col = (colnr_T)STRLEN(ml_get(oap->end.lnum));
-    if (curbuf->b_op_end.col > 0)
-	--curbuf->b_op_end.col;
+    if (!cmdmod.lockmarks)
+    {
+	// Set "'[" and "']" marks.
+	curbuf->b_op_start = oap->start;
+	curbuf->b_op_end.lnum = oap->end.lnum;
+	curbuf->b_op_end.col = (colnr_T)STRLEN(ml_get(oap->end.lnum));
+	if (curbuf->b_op_end.col > 0)
+	    --curbuf->b_op_end.col;
+    }
 }
 
 /*
@@ -981,14 +982,17 @@ op_delete(oparg_T *oap)
     msgmore(curbuf->b_ml.ml_line_count - old_lcount);
 
 setmarks:
-    if (oap->block_mode)
+    if (!cmdmod.lockmarks)
     {
-	curbuf->b_op_end.lnum = oap->end.lnum;
-	curbuf->b_op_end.col = oap->start.col;
+	if (oap->block_mode)
+	{
+	    curbuf->b_op_end.lnum = oap->end.lnum;
+	    curbuf->b_op_end.col = oap->start.col;
+	}
+	else
+	    curbuf->b_op_end = oap->start;
+	curbuf->b_op_start = oap->start;
     }
-    else
-	curbuf->b_op_end = oap->start;
-    curbuf->b_op_start = oap->start;
 
     return OK;
 }
@@ -1252,9 +1256,12 @@ op_replace(oparg_T *oap, int c)
     check_cursor();
     changed_lines(oap->start.lnum, oap->start.col, oap->end.lnum + 1, 0L);
 
-    /* Set "'[" and "']" marks. */
-    curbuf->b_op_start = oap->start;
-    curbuf->b_op_end = oap->end;
+    if (!cmdmod.lockmarks)
+    {
+	/* Set "'[" and "']" marks. */
+	curbuf->b_op_start = oap->start;
+	curbuf->b_op_end = oap->end;
+    }
 
     return OK;
 }
@@ -1362,11 +1369,12 @@ op_tilde(oparg_T *oap)
 	/* No change: need to remove the Visual selection */
 	redraw_curbuf_later(INVERTED);
 
-    /*
-     * Set '[ and '] marks.
-     */
-    curbuf->b_op_start = oap->start;
-    curbuf->b_op_end = oap->end;
+    if (!cmdmod.lockmarks)
+    {
+	// Set '[ and '] marks.
+	curbuf->b_op_start = oap->start;
+	curbuf->b_op_end = oap->end;
+    }
 
     if (oap->line_count > p_report)
 	smsg(NGETTEXT("%ld line changed", "%ld lines changed",
@@ -1973,7 +1981,7 @@ do_join(
     for (t = 0; t < count; ++t)
     {
 	curr = curr_start = ml_get((linenr_T)(curwin->w_cursor.lnum + t));
-	if (t == 0 && setmark)
+	if (t == 0 && setmark && !cmdmod.lockmarks)
 	{
 	    /* Set the '[ mark. */
 	    curwin->w_buffer->b_op_start.lnum = curwin->w_cursor.lnum;
@@ -2129,7 +2137,7 @@ do_join(
 #endif
 	ml_replace(curwin->w_cursor.lnum, newp, FALSE);
 
-    if (setmark)
+    if (setmark && !cmdmod.lockmarks)
     {
 	/* Set the '] mark. */
 	curwin->w_buffer->b_op_end.lnum = curwin->w_cursor.lnum;
@@ -2268,8 +2276,9 @@ op_format(
 	/* When there is no change: need to remove the Visual selection */
 	redraw_curbuf_later(INVERTED);
 
-    /* Set '[ mark at the start of the formatted area */
-    curbuf->b_op_start = oap->start;
+    if (!cmdmod.lockmarks)
+	/* Set '[ mark at the start of the formatted area */
+	curbuf->b_op_start = oap->start;
 
     /* For "gw" remember the cursor position and put it back below (adjusted
      * for joined and split lines). */
@@ -2289,8 +2298,9 @@ op_format(
     old_line_count = curbuf->b_ml.ml_line_count - old_line_count;
     msgmore(old_line_count);
 
-    /* put '] mark on the end of the formatted area */
-    curbuf->b_op_end = curwin->w_cursor;
+    if (!cmdmod.lockmarks)
+	/* put '] mark on the end of the formatted area */
+	curbuf->b_op_end = curwin->w_cursor;
 
     if (keep_cursor)
     {
@@ -2984,7 +2994,7 @@ op_addsub(
 
 	/* Set '[ mark if something changed. Keep the last end
 	 * position from do_addsub(). */
-	if (change_cnt > 0)
+	if (change_cnt > 0 && !cmdmod.lockmarks)
 	    curbuf->b_op_start = startpos;
 
 	if (change_cnt > p_report)
@@ -3384,7 +3394,7 @@ do_addsub(
 	    --curwin->w_cursor.col;
     }
 
-    if (did_change)
+    if (did_change && !cmdmod.lockmarks)
     {
 	/* set the '[ and '] marks */
 	curbuf->b_op_start = startpos;
@@ -3905,6 +3915,8 @@ op_function(oparg_T *oap UNUSED)
 #ifdef FEAT_EVAL
     typval_T	argv[2];
     int		save_virtual_op = virtual_op;
+    pos_T	orig_start = curbuf->b_op_start;
+    pos_T	orig_end = curbuf->b_op_end;
 
     if (*p_opfunc == NUL)
 	emsg(_("E774: 'operatorfunc' is empty"));
@@ -3933,6 +3945,11 @@ op_function(oparg_T *oap UNUSED)
 	(void)call_func_retnr(p_opfunc, 1, argv);
 
 	virtual_op = save_virtual_op;
+	if (cmdmod.lockmarks)
+	{
+	    curbuf->b_op_start = orig_start;
+	    curbuf->b_op_end = orig_end;
+	}
     }
 #else
     emsg(_("E775: Eval feature not available"));
diff --git a/src/register.c b/src/register.c
index 2e838402b6..ee7c618fe9 100644
--- a/src/register.c
+++ b/src/register.c
@@ -1316,13 +1316,16 @@ op_yank(oparg_T *oap, int deleting, int mess)
 	}
     }
 
-    // Set "'[" and "']" marks.
-    curbuf->b_op_start = oap->start;
-    curbuf->b_op_end = oap->end;
-    if (yanktype == MLINE && !oap->block_mode)
+    if (!cmdmod.lockmarks)
     {
-	curbuf->b_op_start.col = 0;
-	curbuf->b_op_end.col = MAXCOL;
+	// Set "'[" and "']" marks.
+	curbuf->b_op_start = oap->start;
+	curbuf->b_op_end = oap->end;
+	if (yanktype == MLINE && !oap->block_mode)
+	{
+	    curbuf->b_op_start.col = 0;
+	    curbuf->b_op_end.col = MAXCOL;
+	}
     }
 
 #ifdef FEAT_CLIPBOARD
@@ -1474,6 +1477,8 @@ do_put(
     char_u	*insert_string = NULL;
     int		allocated = FALSE;
     long	cnt;
+    pos_T	orig_start = curbuf->b_op_start;
+    pos_T	orig_end = curbuf->b_op_end;
 
 #ifdef FEAT_CLIPBOARD
     // Adjust register name for "unnamed" in 'clipboard'.
@@ -2100,6 +2105,11 @@ error:
     curwin->w_set_curswant = TRUE;
 
 end:
+    if (cmdmod.lockmarks)
+    {
+	curbuf->b_op_start = orig_start;
+	curbuf->b_op_end = orig_end;
+    }
     if (allocated)
 	vim_free(insert_string);
     if (regname == '=')
diff --git a/src/testdir/test_autocmd.vim b/src/testdir/test_autocmd.vim
index eba365e399..6d1897a4aa 100644
--- a/src/testdir/test_autocmd.vim
+++ b/src/testdir/test_autocmd.vim
@@ -2297,3 +2297,37 @@ func Test_autocmd_was_using_freed_memory()
   split
   au! WinEnter
 endfunc
+
+func Test_BufWrite_lockmarks()
+  edit! Xtest
+  call setline(1, ['a', 'b', 'c', 'd'])
+
+  " :lockmarks preserves the marks
+  call SetChangeMarks(2, 3)
+  lockmarks write
+  call assert_equal([2, 3], [line("'["), line("']")])
+
+  " *WritePre autocmds get the correct line range, but lockmarks preserves the
+  " original values for the user
+  augroup lockmarks
+    au!
+    au BufWritePre,FilterWritePre * call assert_equal([1, 4], [line("'["), line("']")])
+    au FileWritePre * call assert_equal([3, 4], [line("'["), line("']")])
+  augroup END
+
+  lockmarks write
+  call assert_equal([2, 3], [line("'["), line("']")])
+
+  if executable('cat')
+    lockmarks %!cat
+    call assert_equal([2, 3], [line("'["), line("']")])
+  endif
+
+  lockmarks 3,4write Xtest2
+  call assert_equal([2, 3], [line("'["), line("']")])
+
+  au! lockmarks
+  augroup! lockmarks
+  call delete('Xtest')
+  call delete('Xtest2')
+endfunc
diff --git a/src/testdir/test_diffmode.vim b/src/testdir/test_diffmode.vim
index 6f4eaaf431..9dfe2fefce 100644
--- a/src/testdir/test_diffmode.vim
+++ b/src/testdir/test_diffmode.vim
@@ -989,3 +989,22 @@ func Test_diff_closeoff()
   diffoff!
   enew!
 endfunc
+
+func Test_diff_maintains_change_mark()
+  enew!
+  call setline(1, ['a', 'b', 'c', 'd'])
+  diffthis
+  new
+  call setline(1, ['a', 'b', 'c', 'e'])
+  " Set '[ and '] marks
+  2,3yank
+  call assert_equal([2, 3], [line("'["), line("']")])
+  " Verify they aren't affected by the implicit diff
+  diffthis
+  call assert_equal([2, 3], [line("'["), line("']")])
+  " Verify they aren't affected by an explicit diff
+  diffupdate
+  call assert_equal([2, 3], [line("'["), line("']")])
+  bwipe!
+  bwipe!
+endfunc
diff --git a/src/version.c b/src/version.c
index b91643461d..500ec911fc 100644
--- a/src/version.c
+++ b/src/version.c
@@ -742,6 +742,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2302,
+/**/
     2301,
 /**/
     2300,