Make auto_tags preserve existing tag section structure

autoload/vimwiki/tags.vim

@@ -360,65 +360,70 @@ function! vimwiki#tags#generate_tags(create, ...) abort
 
     " make a dictionary { tag_name: [tag_links, ...] }
     let tags_entries = {}
+    for tagname in self.specific_tags
+      let tags_entries[tagname] = []
+    endfor
+
     for entries in values(metadata)
       for entry in entries
         if has_key(tags_entries, entry.tagname)
           call add(tags_entries[entry.tagname], [entry.link, entry.description])
         else
-          let tags_entries[entry.tagname] = [[entry.link, entry.description]]
+          if need_all_tags
+            let tags_entries[entry.tagname] = [[entry.link, entry.description]]
+          endif
         endif
       endfor
       unlet entry " needed for older vims with sticky type checking since name is reused
     endfor
 
+    let tagnames = need_all_tags ? sort(keys(tags_entries)) : self.specific_tags
     let lines = []
     let bullet = repeat(' ', vimwiki#lst#get_list_margin()).vimwiki#lst#default_symbol().' '
     let current_dir = vimwiki#base#current_subdir()
-    for tagname in sort(keys(tags_entries))
-      if need_all_tags || index(self.specific_tags, tagname) != -1
-        if len(lines) > 0
-          call add(lines, '')
-        endif
+    for tagname in tagnames
+      if len(lines) > 0
+        call add(lines, '')
+      endif
 
-        let tag_tpl = printf('rxH%d_Template', self.header_level + 1)
-        call add(lines, s:safesubstitute(vimwiki#vars#get_syntaxlocal(tag_tpl), '__Header__', tagname, ''))
+      let tag_tpl = printf('rxH%d_Template', self.header_level + 1)
+      call add(lines, s:safesubstitute(vimwiki#vars#get_syntaxlocal(tag_tpl), '__Header__', tagname, ''))
 
-        if vimwiki#vars#get_wikilocal('syntax') ==# 'markdown'
-          for _ in range(vimwiki#vars#get_global('markdown_header_style'))
-            call add(lines, '')
-          endfor
-        endif
+      if vimwiki#vars#get_wikilocal('syntax') ==# 'markdown'
+        for _ in range(vimwiki#vars#get_global('markdown_header_style'))
+          call add(lines, '')
+        endfor
+      endif
 
-        for [taglink, tagdescription] in sort(tags_entries[tagname])
-          let taglink = vimwiki#path#relpath(current_dir, taglink)
-          if vimwiki#vars#get_wikilocal('syntax') ==# 'markdown'
-            let link_tpl = vimwiki#vars#get_syntaxlocal('Weblink3Template')
-            let link_infos = vimwiki#base#resolve_link(taglink)
-            if empty(link_infos.anchor)
-              let link_tpl = vimwiki#vars#get_syntaxlocal('Link1')
-              let entry = s:safesubstitute(link_tpl, '__LinkUrl__', taglink, '')
-              let entry = s:safesubstitute(entry, '__LinkDescription__', tagdescription, '')
-              let file_extension = vimwiki#vars#get_wikilocal('ext', vimwiki#vars#get_bufferlocal('wiki_nr'))
-              let entry = s:safesubstitute(entry, '__FileExtension__', file_extension , '')
-            else
-              let link_caption = split(tagdescription, '#', 0)[-1]
-              let link_text = split(taglink, '#', 1)[0]
-              let entry = s:safesubstitute(link_tpl, '__LinkUrl__', link_text, '')
-              let entry = s:safesubstitute(entry, '__LinkAnchor__', link_infos.anchor, '')
-              let entry = s:safesubstitute(entry, '__LinkDescription__', link_caption, '')
-              let file_extension = vimwiki#vars#get_wikilocal('ext', vimwiki#vars#get_bufferlocal('wiki_nr'))
-              let entry = s:safesubstitute(entry, '__FileExtension__', file_extension , '')
-            endif
-
-            call add(lines, bullet . entry)
+      for [taglink, tagdescription] in sort(tags_entries[tagname])
+        let taglink = vimwiki#path#relpath(current_dir, taglink)
+        if vimwiki#vars#get_wikilocal('syntax') ==# 'markdown'
+          let link_tpl = vimwiki#vars#get_syntaxlocal('Weblink3Template')
+          let link_infos = vimwiki#base#resolve_link(taglink)
+          if empty(link_infos.anchor)
+            let link_tpl = vimwiki#vars#get_syntaxlocal('Link1')
+            let entry = s:safesubstitute(link_tpl, '__LinkUrl__', taglink, '')
+            let entry = s:safesubstitute(entry, '__LinkDescription__', tagdescription, '')
+            let file_extension = vimwiki#vars#get_wikilocal('ext', vimwiki#vars#get_bufferlocal('wiki_nr'))
+            let entry = s:safesubstitute(entry, '__FileExtension__', file_extension , '')
           else
-            let link_tpl = vimwiki#vars#get_global('WikiLinkTemplate1')
+            let link_caption = split(tagdescription, '#', 0)[-1]
+            let link_text = split(taglink, '#', 1)[0]
+            let entry = s:safesubstitute(link_tpl, '__LinkUrl__', link_text, '')
+            let entry = s:safesubstitute(entry, '__LinkAnchor__', link_infos.anchor, '')
+            let entry = s:safesubstitute(entry, '__LinkDescription__', link_caption, '')
             let file_extension = vimwiki#vars#get_wikilocal('ext', vimwiki#vars#get_bufferlocal('wiki_nr'))
-            let link_tpl = s:safesubstitute(link_tpl, '__FileExtension__', file_extension , '')
-            call add(lines, bullet . substitute(link_tpl, '__LinkUrl__', taglink, ''))
+            let entry = s:safesubstitute(entry, '__FileExtension__', file_extension , '')
           endif
-        endfor
-      endif
+
+          call add(lines, bullet . entry)
+        else
+          let link_tpl = vimwiki#vars#get_global('WikiLinkTemplate1')
+          let file_extension = vimwiki#vars#get_wikilocal('ext', vimwiki#vars#get_bufferlocal('wiki_nr'))
+          let link_tpl = s:safesubstitute(link_tpl, '__FileExtension__', file_extension , '')
+          call add(lines, bullet . substitute(link_tpl, '__LinkUrl__', taglink, ''))
+        endif
+      endfor
     endfor
 
     return lines

test/tag_update_existing_heading.vader

@@ -0,0 +1,63 @@
+# Test how vimwiki#tags#generate_tags behaves when updating existing tag link sections
+
+Before (Setup test wiki files):
+  call writefile([":usedtag:", ":othertag:"], expand("~/testmarkdown/Test-Tag-tagged.md"))
+  edit ~/testmarkdown/Test-Tag-links.md
+
+After (Cleanup files):
+  %delete
+  call system("rm $HOME/testmarkdown/.vimwiki_tags")
+  call system("rm $HOME/testmarkdown/Test-Tag-tagged.md")
+  call system("rm $HOME/testmarkdown/Test-Tag-links.md")
+
+
+Do (Create preexisting tag links with unused tag):
+  I
+  # Generated Tags\<CR>
+  \<CR>
+  ## unusedtag\<CR>
+  \<CR>
+  ## usedtag\<CR>
+  \<ESC>
+  :VimwikiRebuildTags!\<CR>
+  :call vimwiki#tags#generate_tags(0)\<CR>
+
+Expect (Keeps unused tag header):
+  # Generated Tags
+
+  ## unusedtag
+
+
+  ## usedtag
+
+  - [Test-Tag-tagged](Test-Tag-tagged)
+
+Do (Create preexisting tag subheadings out of alphabetical order):
+  I
+  # Generated Tags\<CR>
+  \<CR>
+  ## z\<CR>
+  \<CR>
+  ## usedtag\<CR>
+  \<CR>
+  ## a\<CR>
+  \<CR>
+  # Other Stuff
+  \<ESC>
+  :VimwikiRebuildTags!\<CR>
+  :call vimwiki#tags#generate_tags(0)\<CR>
+
+Expect (Existing tag subheading order is preserved):
+  # Generated Tags
+
+  ## z
+
+
+  ## usedtag
+
+  - [Test-Tag-tagged](Test-Tag-tagged)
+
+  ## a
+
+
+  # Other Stuff