patch 9.1.0265: console dialog cannot save unnamed buffers

Problem:  console dialog cannot save unnamed buffers
Solution: set bufname before save (glepnir). Define dialog_con_gui
          to test for GUI+Console dialog support, use it to skip
          the test when the GUI feature has been defined.

Note: The dialog_changed() function will also try to call the
browse_save_fname() function, when FEAT_BROWSE is defined (which is only
defined in a GUI build of Vim). This will eventually lead to a call of
do_browse(), which causes an error message if a GUI is not currently
running (see the TODO: in do_browse()) and will then lead to a failure
in Test_goto_buf_with_onfirm().

Therefore, we must disable the Test_goto_buf_with_onfirm(), when the
dialog_con_gui feature is enabled (which basically means dialog feature
for GUI and Console builds, in contrast to the dialog_con and dialog_gui
feature).

(Previously this wasn't a problem, because the test aborted in the YES
case for the :confirm :b XgotoConf case and did therefore not run into
the browse function call)

closes: #14398

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/builtin.txt

@@ -1,4 +1,4 @@
-*builtin.txt*	For Vim version 9.1.  Last change: 2024 Apr 03
+*builtin.txt*	For Vim version 9.1.  Last change: 2024 Apr 04
 
 
 		  VIM REFERENCE MANUAL	  by Bram Moolenaar
@@ -1771,7 +1771,7 @@ confirm({msg} [, {choices} [, {default} [, {type}]]])
 		made.  It returns the number of the choice.  For the first
 		choice this is 1.
 		Note: confirm() is only supported when compiled with dialog
-		support, see |+dialog_con| and |+dialog_gui|.
+		support, see |+dialog_con| |+dialog_con_gui| and |+dialog_gui|.
 
 		{msg} is displayed in a |dialog| with {choices} as the
 		alternatives.  When {choices} is missing or empty, "&OK" is
@@ -11200,6 +11200,7 @@ cscope			Compiled with |cscope| support.
 cursorbind		Compiled with |'cursorbind'| (always true)
 debug			Compiled with "DEBUG" defined.
 dialog_con		Compiled with console dialog support.
+dialog_con_gui		Compiled with console and GUI dialog support.
 dialog_gui		Compiled with GUI dialog support.
 diff			Compiled with |vimdiff| and 'diff' support.
 digraphs		Compiled with support for digraphs.

src/evalfunc.c

@@ -6127,6 +6127,13 @@ f_has(typval_T *argvars, typval_T *rettv)
 		1
 #else
 		0
+#endif
+		},
+	{"dialog_con_gui",
+#if defined(FEAT_CON_DIALOG) && defined(FEAT_GUI_DIALOG)
+		1
+#else
+		0
 #endif
 		},
 	{"dialog_gui",

src/ex_cmds2.c

@@ -163,7 +163,8 @@ dialog_changed(
     char_u	buff[DIALOG_MSG_SIZE];
     int		ret;
     buf_T	*buf2;
-    exarg_T     ea;
+    exarg_T	ea;
+    int		empty_buf = buf->b_fname == NULL ? TRUE : FALSE;
 
     dialog_msg(buff, _("Save changes to \"%s\"?"), buf->b_fname);
     if (checkall)
@@ -181,10 +182,27 @@ dialog_changed(
 	// May get file name, when there is none
 	browse_save_fname(buf);
 #endif
-	if (buf->b_fname != NULL && check_overwrite(&ea, buf,
-				    buf->b_fname, buf->b_ffname, FALSE) == OK)
+	if (empty_buf)
+	    buf_set_name(buf->b_fnum, (char_u *)"Untitled");
+
+	if (check_overwrite(&ea, buf, buf->b_fname, buf->b_ffname, FALSE) == OK)
+	{
 	    // didn't hit Cancel
-	    (void)buf_write_all(buf, FALSE);
+	    if (buf_write_all(buf, FALSE) == OK)
+		return;
+	}
+
+	// restore to empty when write failed
+	if (empty_buf)
+	{
+	    vim_free(buf->b_fname);
+	    buf->b_fname = NULL;
+	    vim_free(buf->b_ffname);
+	    buf->b_ffname = NULL;
+	    vim_free(buf->b_sfname);
+	    buf->b_sfname = NULL;
+	    unchanged(buf, TRUE, FALSE);
+	}
     }
     else if (ret == VIM_NO)
     {

src/testdir/test_buffer.vim

@@ -252,21 +252,30 @@ func Test_goto_buf_with_confirm()
   CheckUnix
   CheckNotGui
   CheckFeature dialog_con
+  " When dialog_con_gui is defined, Vim is compiled with GUI support
+  " and FEAT_BROWSE will be defined, which causes :confirm :b to
+  " call do_browse(), which will try to use a GUI file browser,
+  " which aborts if a GUI is not available.
+  CheckNotFeature dialog_con_gui
   new XgotoConf
   enew
   call setline(1, 'test')
   call assert_fails('b XgotoConf', 'E37:')
   call feedkeys('c', 'L')
   call assert_fails('confirm b XgotoConf', 'E37:')
-  call assert_equal(1, &modified)
-  call assert_equal('', @%)
+  call assert_true(&modified)
+  call assert_true(empty(bufname('%')))
   call feedkeys('y', 'L')
-  call assert_fails('confirm b XgotoConf', ['', 'E37:'])
-  call assert_equal(1, &modified)
-  call assert_equal('', @%)
+  confirm b XgotoConf
+  call assert_equal('XgotoConf', bufname('%'))
+  call assert_equal(['test'], readfile('Untitled'))
+  e Untitled
+  call setline(2, 'test2')
   call feedkeys('n', 'L')
   confirm b XgotoConf
-  call assert_equal('XgotoConf', @%)
+  call assert_equal('XgotoConf', bufname('%'))
+  call assert_equal(['test'], readfile('Untitled'))
+  call delete('Untitled')
   close!
 endfunc
 

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    265,
 /**/
     264,
 /**/