wip GBrowse api

Author: tpope

autoload/fugitive.vim

@@ -7561,8 +7561,9 @@ function! fugitive#BrowseCommand(line1, count, range, bang, mods, arg, ...) abor
           endif
         endif
       endif
+      let commit_id = fugitive#RevParse(empty(ref) ? 'HEAD' : ref, dir)
       if empty(commit)
-        let commit = fugitive#RevParse(empty(ref) ? 'HEAD' : ref, dir)
+        let commit = commit_id
       endif
     endif
 
@@ -7579,6 +7580,8 @@ function! fugitive#BrowseCommand(line1, count, range, bang, mods, arg, ...) abor
           \ 'repo': {'git_dir': git_dir},
           \ 'remote': raw,
           \ 'remote_name': remote,
+          \ 'starting_ref': empty(ref) ? 'HEAD' : ref,
+          \ 'commit_id': exists('commit_id') ? commit_id : commit,
           \ 'commit': s:UrlEncode(commit),
           \ 'path': substitute(s:UrlEncode(path), '%20', ' ', 'g'),
           \ 'type': type,