Added test files

test/issues/630/localpackage.sty

@@ -0,0 +1,2 @@
+\ProvidesPackage{localpackage}
+\endinput

test/issues/630/main.tex

@@ -0,0 +1,10 @@
+\documentclass{article}
+\usepackage{filecontents}
+\usepackage{subfiles}
+\usepackage{localpackage}
+
+\begin{document}
+\subfile{sub/sub.tex}
+
+b
+\end{document}

test/issues/630/minivimrc

@@ -0,0 +1,17 @@
+set nocompatible
+let &rtp  = '~/.vim/bundle/vimtex,' . &rtp
+let &rtp .= ',~/.vim/bundle/vimtex/after'
+filetype plugin indent on
+syntax enable
+
+let g:tex_flavor = "latex"
+let g:vimtex_latexmk_background = 1
+
+let g:vimtex_view_general_viewer = 'SumatraPDF'
+let g:vimtex_view_general_options =
+      \ '-reuse-instance -forward-search @line @pdf @tex'
+let g:vimtex_view_general_options_latexmk = '-reuse-instance'
+
+if !has('win32')
+  echoerr 'This test case should be run on windows!'
+endif

test/issues/630/sub/sub.tex

@@ -0,0 +1,5 @@
+\documentclass[main.tex]{subfiles}
+
+\begin{document}
+a
+\end{document}