patch 8.2.3392: augroup completion escapes regexp pattern characters

Problem:    augroup completion escapes regexp pattern characters.
Solution:   Do not escape the augroup name. (closes #8826)

Author: brammool

src/cmdexpand.c

@@ -2134,8 +2134,8 @@ ExpandFromContext(
 	    {EXPAND_SYNTIME, get_syntime_arg, TRUE, TRUE},
 # endif
 	    {EXPAND_HIGHLIGHT, get_highlight_name, TRUE, TRUE},
-	    {EXPAND_EVENTS, get_event_name, TRUE, TRUE},
-	    {EXPAND_AUGROUP, get_augroup_name, TRUE, TRUE},
+	    {EXPAND_EVENTS, get_event_name, TRUE, FALSE},
+	    {EXPAND_AUGROUP, get_augroup_name, TRUE, FALSE},
 # ifdef FEAT_CSCOPE
 	    {EXPAND_CSCOPE, get_cscope_name, TRUE, TRUE},
 # endif

src/testdir/test_cmdline.vim

@@ -876,11 +876,13 @@ func Test_cmdline_complete_various()
   call delete('Xfile2')
 
   " completion for the :augroup command
-  augroup XTest
+  augroup XTest.test
   augroup END
   call feedkeys(":augroup X\<C-A>\<C-B>\"\<CR>", 'xt')
-  call assert_equal("\"augroup XTest", @:)
-  augroup! XTest
+  call assert_equal("\"augroup XTest.test", @:)
+  call feedkeys(":au X\<C-A>\<C-B>\"\<CR>", 'xt')
+  call assert_equal("\"au XTest.test", @:)
+  augroup! XTest.test
 
   " completion for the :unlet command
   call feedkeys(":unlet one two\<C-A>\<C-B>\"\<CR>", 'xt')

src/version.c

@@ -755,6 +755,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    3392,
 /**/
     3391,
 /**/