patch 8.0.0470: not enough testing for help commands

Problem:    Not enough testing for help commands.
Solution:   Add a few more help tests. (Dominique Pelle, closes #1565)

src/testdir/test_help.vim

@@ -8,3 +8,8 @@ func Test_help_restore_snapshot()
   help
   helpclose
 endfunc
+
+func Test_help_errors()
+  call assert_fails('help doesnotexist', 'E149:')
+  call assert_fails('help!', 'E478:')
+endfunc

src/testdir/test_help_tagjump.vim

@@ -6,6 +6,52 @@ func Test_help_tagjump()
   call assert_true(getline('.') =~ '\*help.txt\*')
   helpclose
 
+  help |
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*bar\*')
+  helpclose
+
+  help "*
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*quotestar\*')
+  helpclose
+
+  help sm?le
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*:smile\*')
+  helpclose
+
+  help :?
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*:?\*')
+  helpclose
+
+  help FileW*Post
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*FileWritePost\*')
+  helpclose
+
+  help `ls`
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*:ls\*')
+  helpclose
+
+  help ^X
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*CTRL-X\*')
+  helpclose
+
+  help i_^_CTRL-D
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*i_^_CTRL-D\*')
+  helpclose
+
+  exec "help \<C-V>"
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*CTRL-V\*')
+  helpclose
+
+
   exec "help! ('textwidth'"
   call assert_equal("help", &filetype)
   call assert_true(getline('.') =~ "\\*'textwidth'\\*")
@@ -35,6 +81,16 @@ func Test_help_tagjump()
   call assert_equal("help", &filetype)
   call assert_true(getline('.') =~ '\*{address}\*')
   helpclose
+
+  exusage
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*:index\*')
+  helpclose
+
+  viusage
+  call assert_equal("help", &filetype)
+  call assert_true(getline('.') =~ '\*normal-index\*')
+  helpclose
 endfunc
 
 let s:langs = ['en', 'ab', 'ja']

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    470,
 /**/
     469,
 /**/