patch 7.4.1571

Problem:    No test for ":help".
Solution:   Add a test for what 7.4.1568 fixed. (Higashi Higashi)

src/testdir/test_alot.vim

@@ -9,6 +9,7 @@ source test_expand.vim
 source test_feedkeys.vim
 source test_file_perm.vim
 source test_glob2regpat.vim
+source test_help_tagjump.vim
 source test_join.vim
 source test_lispwords.vim
 source test_menu.vim

src/testdir/test_help_tagjump.vim

@@ -0,0 +1,18 @@
+" Tests for :help! {subject}
+
+func Test_help_tagjump()
+  help
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*help.txt\*')
+  helpclose
+
+  exec "help! ('textwidth'"
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ "\\*'textwidth'\\*")
+  helpclose
+
+  exec "help! ('buflisted'),"
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ "\\*'buflisted'\\*")
+  helpclose
+endfunc

src/version.c

@@ -743,6 +743,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1571,
 /**/
     1570,
 /**/