plugin/magit.vim: add mappings N and P to jump to next and previous h…

…unk (fix #25)

README.md

@@ -64,6 +64,9 @@ Open magit buffer.
 
 All files diffs are hidden by default. To inspect changes in a file, move cursor to the filename line, and press 'Enter' in Normal mode. Diffs are displayed below the file name.
 
+#### N
+* Jump to next hunk with **N**.
+
 #### S
 
 * Modify a file, for example foo.c, in your repository.
@@ -184,6 +187,9 @@ Following mappings are set locally, for magit buffer only, in normal mode.
  * If cursor is in diff header, discard whole file at cursor position.
  * Only works in "Unstaged changes" section.
 
+##### N,P
+ * Move to **N**ext or **P**revious hunk.
+
 ##### CC
  * If not in commit section, set commit mode to "New commit" and show "Commit message" section with brand new commit message.
  * If in commit section, commit the all staged changes in commit mode previously set.

doc/vimagit.txt

@@ -59,6 +59,11 @@ All files diffs are hidden by default. To inspect changes in a file, move
 cursor to the filename line, and press 'Enter' in Normal mode. Diffs are
 displayed below the file name.
 
+  N
+-----------
+
+* Jump to next hunk with N.
+
   S
 -----------
 
@@ -223,6 +228,10 @@ Following mappings are set locally, for magit buffer only, in normal mode.
             position.
             Only works in "Unstaged changes" section.
 
+                                    *vimagit-N*                *magit#jump_hunk()*
+                                    *vimagit-P*
+  N,P       Move to Next or Previous hunk.
+
                                     *vimagit-CC*      *magit#commit_command('CC')*
                                     *vimagit-g:magit_commit_mapping*
   CC        If not in commit section, set commit mode to "New commit" and show 

plugin/magit.vim

@@ -38,6 +38,8 @@ let g:magit_folding_toggle_mapping = get(g:, 'magit_folding_toggle_mapping',
 let g:magit_folding_open_mapping   = get(g:, 'magit_folding_open_mapping',      [ 'zo', 'zO' ])
 let g:magit_folding_close_mapping  = get(g:, 'magit_folding_close_mapping',     [ 'zc', 'zC' ])
 
+let g:magit_jump_next_hunk         = get(g:, 'magit_jump_next_hunk',            'N')
+let g:magit_jump_prev_hunk         = get(g:, 'magit_jump_prev_hunk',            'P')
 " user options
 let g:magit_enabled                = get(g:, 'magit_enabled',                   1)
 let g:magit_show_help              = get(g:, 'magit_show_help',                 0)
@@ -665,7 +667,10 @@ function! magit#show_magit(display, ...)
 
 	execute "nnoremap <buffer> <silent> " . g:magit_mark_line_mapping .    " :call magit#mark_vselect()<cr>"
 	execute "xnoremap <buffer> <silent> " . g:magit_mark_line_mapping .    " :call magit#mark_vselect()<cr>"
-
+
+	execute "nnoremap <buffer> <silent> " . g:magit_jump_next_hunk .       " :call magit#jump_hunk('N')<cr>"
+	execute "nnoremap <buffer> <silent> " . g:magit_jump_prev_hunk .       " :call magit#jump_hunk('P')<cr>"
+
 	for mapping in g:magit_folding_toggle_mapping
 		" trick to pass '<cr>' in a mapping command without being interpreted
 		let func_arg = ( mapping ==? "<cr>" ) ? '+' : mapping
@@ -918,6 +923,28 @@ function! magit#commit_command(mode)
 	call magit#update_buffer()
 endfunction
 
+" magit#jump_hunk: function to jump among hunks
+" it closes the current fold (if any), jump to next hunk and unfold it
+" param[in] dir: can be 'N' (for next) or 'P' (for previous)
+function! magit#jump_hunk(dir)
+	let back = ( a:dir == 'P' ) ? 'b' : ''
+	let line = search("^@@ ", back . 'wn')
+	if ( line != 0 )
+		try
+			foldclose
+		catch /^Vim\%((\a\+)\)\=:E490/
+		endtry
+		call cursor(line, 0)
+		try
+			foldopen
+		catch /^Vim\%((\a\+)\)\=:E490/
+			echohl WarningMsg
+			echom "Warning: you should have jumped on a folded hunk"
+			echohl None
+		endtry
+	endif
+endfunction
+
 command! Magit call magit#show_magit('v')
 command! MagitOnly call magit#show_magit('c')