diff_corrections: Add `cx` mapping to close tab

Add a mapping to quickly close a tab. Makes it easier to close files
that I've finished reviewing.

Thanks to user9433424
(https://vi.stackexchange.com/users/6960/user9433424) on the Vi Stack
Exchange for the very detailed explanation of how to restore a mapping:
https://vi.stackexchange.com/questions/7734/how-to-save-and-restore-a-mapping/7735#7735

Using user9433424's mapping restore code, and ignoring the case where a
mapping is defined both globally and local to a buffer.

1 files changed, 26 insertions, 0 deletions

diff --git a/bundle/diff-corrections/autoload/diff_corrections.vim b/bundle/diff-corrections/autoload/diff_corrections.vim
index 620c1b0..c3003e9 100644
--- a/bundle/diff-corrections/autoload/diff_corrections.vim
+++ b/bundle/diff-corrections/autoload/diff_corrections.vim
@@ -1,4 +1,6 @@
 let s:old_cursorline = &cursorline
+let s:restore_cx_mapping = ''
+
 
 function! diff_corrections#Run()
 	if &diff
@@ -7,12 +9,18 @@ function! diff_corrections#Run()
 		endif
 
 		set nocursorline
+
+		nnoremap cx :<C-u>tabclose<CR>
 	else
 		if exists('g:colors_name') && g:colors_name ==# 'twilight256'
 			execute 'highlight ' . s:old_highlight_comment
 		endif
 
 		let &cursorline = s:old_cursorline
+
+		if strlen(s:restore_cx_mapping) > 0
+			execute s:restore_cx_mapping
+		endif
 	endif
 endfunction
 
@@ -32,4 +40,22 @@ function! s:SaveCommentColor()
 endfunction
 
 
+function! s:SaveMapping()
+	let mapping = maparg('cx', 'n', 0, 1)
+
+	if !empty(mapping)
+		let s:restore_cx_mapping .= (mapping.noremap ? 'nnoremap' : 'nmap') .
+			\ join(
+				\ map(
+					\ ['buffer', 'expr', 'nowait', 'silent'],
+					\ 'mapping[v:val] ? "<" . v:val . ">" : ""'
+				\ )
+			\ ) .
+			\ mapping.lhs . ' ' .
+			\ substitute(mapping.rhs, '<SID>', '<SNR>' . mapping.sid . '_', 'g')
+	endif
+endfunction
+
+
 let s:old_highlight_comment = s:SaveCommentColor()
+call s:SaveMapping()