patch 8.1.1546: in some tests 'tags' is set but not restored

Problem:    In some tests 'tags' is set but not restored. (Daniel Hahler)
Solution:   Restore 'tags'. (closes #4535)

src/testdir/test_autocmd.vim

@@ -1100,6 +1100,7 @@ func Test_OptionSet()
 
   " Cleanup
   au! OptionSet
+  " set tags&
   for opt in ['nu', 'ai', 'acd', 'ar', 'bs', 'backup', 'cul', 'cp', 'backupext', 'tags', 'spelllang', 'statusline', 'foldignore', 'cmdheight', 'undolevels', 'wrapmargin', 'foldcolumn', 'wrapscan', 'autoread', 'cindent', 'cursorcolumn']
     exe printf(":set %s&vim", opt)
   endfor

src/testdir/test_cmdline.vim

@@ -378,6 +378,7 @@ func Test_getcompletion()
   endfor
 
   call delete('Xtags')
+  set tags&
 
   call assert_fails('call getcompletion("", "burp")', 'E475:')
 endfunc

src/testdir/test_options.vim

@@ -237,6 +237,7 @@ func Test_set_completion()
 
   call feedkeys(":set tags=./\\\\ dif\<C-A>\<C-B>\"\<CR>", 'tx')
   call assert_equal('"set tags=./\\ diff diffexpr diffopt', @:)
+  set tags&
 endfunc
 
 func Test_set_errors()

src/testdir/test_tagcase.vim

@@ -44,6 +44,7 @@ func Test_tagcase()
   endfor
 
   call delete('Xtags')
+  set tags&
   set ic&
   setg tc&
   setl tc&

src/testdir/test_tagjump.vim

@@ -20,6 +20,7 @@ func Test_cancel_ptjump()
   call assert_equal(2, winnr('$'))
 
   call delete('Xtags')
+  set tags&
   quit
 endfunc
 
@@ -104,6 +105,7 @@ func Test_tagjump_switchbuf()
   enew | only
   call delete('Xfile1')
   call delete('Xtags')
+  set tags&
   set switchbuf&vim
 endfunc
 
@@ -431,7 +433,7 @@ func Test_tagnr_recall()
   tag
   call assert_equal(bufname('%'), 'Xtest.h')
 
-  set tag&
+  set tags&
   call delete('Xtags')
   bwipe Xtest.h
   bwipe Xtest.c
@@ -467,6 +469,7 @@ func Test_tag_line_toolong()
   endtry
   call assert_equal('Ignoring long line in tags file', split(execute('messages'), '\n')[-1])
   call delete('Xtags')
+  set tags&
   let &verbose = old_vbs
 endfunc
 

src/testdir/test_taglist.vim

@@ -30,6 +30,7 @@ func Test_taglist()
   call assert_equal('call cursor(3, 4)', cmd[0]['cmd'])
 
   call delete('Xtags')
+  set tags&
   bwipe
 endfunc
 
@@ -50,6 +51,7 @@ func Test_taglist_native_etags()
 	\ map(taglist('set_signals'), {i, v -> [v.name, v.cmd]}))
 
   call delete('Xtags')
+  set tags&
 endfunc
 
 func Test_taglist_ctags_etags()
@@ -69,6 +71,7 @@ func Test_taglist_ctags_etags()
 	\ map(taglist('set_signals'), {i, v -> [v.name, v.cmd]}))
 
   call delete('Xtags')
+  set tags&
 endfunc
 
 func Test_tags_too_long()
@@ -110,4 +113,5 @@ func Test_tagsfile_without_trailing_newline()
   call assert_equal('Foo', tl[0].name)
 
   call delete('Xtags')
+  set tags&
 endfunc

src/version.c

@@ -777,6 +777,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1546,
 /**/
     1545,
 /**/