patch 8.2.2669: command line completion does not work after "vim9"

Problem:    Command line completion does not work after "vim9".
Solution:   Include the "9". (Naohiro Ono, closes #8025)
diff --git a/src/cmdexpand.c b/src/cmdexpand.c
index d51f5c6..280b9e4 100644
--- a/src/cmdexpand.c
+++ b/src/cmdexpand.c
@@ -1020,8 +1020,9 @@
 	p = cmd;
 	while (ASCII_ISALPHA(*p) || *p == '*')    // Allow * wild card
 	    ++p;
-	// a user command may contain digits
-	if (ASCII_ISUPPER(cmd[0]))
+	// A user command may contain digits.
+	// Include "9" for "vim9*" commands; "vim9cmd" and "vim9script".
+	if (ASCII_ISUPPER(cmd[0]) || STRNCMP("vim9", cmd, 4) == 0)
 	    while (ASCII_ISALNUM(*p) || *p == '*')
 		++p;
 	// for python 3.x: ":py3*" commands completion
diff --git a/src/ex_docmd.c b/src/ex_docmd.c
index 7a03597..b4e3553 100644
--- a/src/ex_docmd.c
+++ b/src/ex_docmd.c
@@ -3553,7 +3553,7 @@
 	}
 	else if (*p == '9' && STRNCMP("vim9", eap->cmd, 4) == 0)
 	{
-	    // include "9" for "vim9script"
+	    // include "9" for "vim9*" commands; "vim9cmd" and "vim9script".
 	    ++p;
 	    while (ASCII_ISALPHA(*p))
 		++p;
diff --git a/src/testdir/test_cmdline.vim b/src/testdir/test_cmdline.vim
index 05d90f7..531837b 100644
--- a/src/testdir/test_cmdline.vim
+++ b/src/testdir/test_cmdline.vim
@@ -871,6 +871,10 @@
   call feedkeys(":py3\<C-A>\<C-B>\"\<CR>", 'xt')
   call assert_equal('"py3 py3do py3file', @:)
 
+  " completion for the :vim9 commands
+  call feedkeys(":vim9\<C-A>\<C-B>\"\<CR>", 'xt')
+  call assert_equal('"vim9cmd vim9script', @:)
+
   " redir @" is not the start of a comment. So complete after that
   call feedkeys(":redir @\" | cwin\t\<C-B>\"\<CR>", 'xt')
   call assert_equal('"redir @" | cwindow', @:)
diff --git a/src/version.c b/src/version.c
index 716f41e..00d2fd7 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2669,
+/**/
     2668,
 /**/
     2667,