github-url: Fix URL generation when `:pwd` is below repository root

If the `:pwd` was a subdirectory of the repository root, the path in the
constructed GitHub URL would not include any subdirectories up to and
including the current working directory. This created an incorrect path
in the URL, resulting in a 404.

1 files changed, 12 insertions, 2 deletions

diff --git a/bundle/github-url/autoload/github_url.vim b/bundle/github-url/autoload/github_url.vim
index e090681..713ba89 100644
--- a/bundle/github-url/autoload/github_url.vim
+++ b/bundle/github-url/autoload/github_url.vim
@@ -16,7 +16,7 @@ endfunction
 function! s:FileURL(include_lines, start_line, end_line)
 	let current_sha = system('git show --no-patch --format="format:%H"')
 	let current_sha = substitute(current_sha, '\n$', '', '')
-	let current_filename = expand('%')
+	let current_filename = s:FilePathRelativeToRepoRoot()
 	let lines = ''
 
 	if a:include_lines
@@ -27,7 +27,7 @@ function! s:FileURL(include_lines, start_line, end_line)
 		endif
 	endif
 
-	return s:BaseRepoURL() . '/blob/' . current_sha . '/' . current_filename . lines
+	return s:BaseRepoURL() . '/blob/' . current_sha . current_filename . lines
 endfunction
 
 " Copy the GitHub URL to the clipboard and echo it to the command line.
@@ -37,3 +37,13 @@ function! github_url#GitHubURL(include_lines, start_line, end_line)
 	call system('pbcopy', url)
 	echo url
 endfunction
+
+" Get the path of the current file relative to the repository root. Gives us
+" the correct path to the file even if `:pwd` is below the Git root. The
+" returned path begins with a `/`.
+function! s:FilePathRelativeToRepoRoot()
+	let repo_root = system('git rev-parse --show-toplevel')[:-2]
+	let current_file_absolute = expand('%:p')
+
+	return substitute(current_file_absolute, repo_root, '', '')
+endfunction