patch 8.0.0402: :map completion does not have <special>

Problem:    :map completion does not have <special>. (Dominique Pelle)
Solution:   Recognize <special> in completion.  Add a test.

src/getchar.c

@@ -4216,6 +4216,11 @@ set_context_in_map_cmd(
 		arg = skipwhite(arg + 8);
 		continue;
 	    }
+	    if (STRNCMP(arg, "<special>", 9) == 0)
+	    {
+		arg = skipwhite(arg + 9);
+		continue;
+	    }
 #ifdef FEAT_EVAL
 	    if (STRNCMP(arg, "<script>", 8) == 0)
 	    {
@@ -4267,7 +4272,7 @@ ExpandMappings(
     {
 	count = 0;
 
-	for (i = 0; i < 6; ++i)
+	for (i = 0; i < 7; ++i)
 	{
 	    if (i == 0)
 		p = (char_u *)"<silent>";
@@ -4285,6 +4290,8 @@ ExpandMappings(
 #endif
 	    else if (i == 5)
 		p = (char_u *)"<nowait>";
+	    else if (i == 6)
+		p = (char_u *)"<special>";
 	    else
 		continue;
 

src/testdir/test_cmdline.vim

@@ -25,6 +25,26 @@ func Test_complete_wildmenu()
   set nowildmenu
 endfunc
 
+func Test_map_completion()
+  if !has('cmdline_compl')
+    return
+  endif
+  call feedkeys(":map <unique> <si\<Tab>\<Home>\"\<CR>", 'xt')
+  call assert_equal('"map <unique> <silent>', getreg(':'))
+  call feedkeys(":map <script> <un\<Tab>\<Home>\"\<CR>", 'xt')
+  call assert_equal('"map <script> <unique>', getreg(':'))
+  call feedkeys(":map <expr> <sc\<Tab>\<Home>\"\<CR>", 'xt')
+  call assert_equal('"map <expr> <script>', getreg(':'))
+  call feedkeys(":map <buffer> <e\<Tab>\<Home>\"\<CR>", 'xt')
+  call assert_equal('"map <buffer> <expr>', getreg(':'))
+  call feedkeys(":map <nowait> <b\<Tab>\<Home>\"\<CR>", 'xt')
+  call assert_equal('"map <nowait> <buffer>', getreg(':'))
+  call feedkeys(":map <special> <no\<Tab>\<Home>\"\<CR>", 'xt')
+  call assert_equal('"map <special> <nowait>', getreg(':'))
+  call feedkeys(":map <silent> <sp\<Tab>\<Home>\"\<CR>", 'xt')
+  call assert_equal('"map <silent> <special>', getreg(':'))
+endfunc
+
 func Test_match_completion()
   if !has('cmdline_compl')
     return

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    402,
 /**/
     401,
 /**/