Support subequations label completion

autoload/vimtex/complete.vim

@@ -395,8 +395,7 @@ function! s:labels_parse_number(num_tree) " {{{1
       return s:labels_parse_number(a:num_tree[l:index])
     endif
   else
-    let l:num = str2nr(a:num_tree)
+    return str2nr(a:num_tree) > 0 ? a:num_tree : '-'
-    return l:num > 0 ? l:num : '-'
   endif
 endfunction
 

test/feature/completions/main.tex

@@ -1,5 +1,6 @@
 \documentclass{article}
 \usepackage{biblatex}
+\usepackage{amsmath}
 \addbibresource{biblatex-examples.bib}
 \addbibresource{local1.bib}
 \addbibresource{~/.vim/bundle/vim-latex/test/completion/local2.bib}
@@ -68,4 +69,13 @@ To test label completion you need to compile the document first!
   f(x) = 10
 \end{equation}
 
+\begin{subequations}
+  \begin{align}
+    \label{eq:test11a}
+    f(x) &= 11a \\
+    \label{eq:test11b}
+    f(x) &= 11b
+  \end{align}
+\end{subequations}
+
 \end{document}