LaTeX-Box-Team/LaTeX-Box — pull request #62 by sappjw (2013-01-11 15:41:02+00:00)
Title: Prepend current directory to path of main TeX file specified by '! TEX root =' comment

Compilation of a multi-file document doesn't work if the main TeX file hasn't been opened by the same instance of vim. This patch treats the file name in the '! TEX root =' comment as a file relative to the file containing the comment, unless it starts with a '/'.