whitespace: Also check for Git conflict markers

autoload/airline/extensions/whitespace.vim

@@ -7,7 +7,7 @@ scriptencoding utf-8
 
 let s:show_message = get(g:, 'airline#extensions#whitespace#show_message', 1)
 let s:symbol = get(g:, 'airline#extensions#whitespace#symbol', g:airline_symbols.whitespace)
-let s:default_checks = ['indent', 'trailing', 'mixed-indent-file']
+let s:default_checks = ['indent', 'trailing', 'mixed-indent-file', 'conflicts']
 
 let s:enabled = get(g:, 'airline#extensions#whitespace#enabled', 1)
 let s:skip_check_ft = {'make': ['indent', 'mixed-indent-file']}
@@ -47,6 +47,14 @@ function! s:check_mixed_indent_file()
   endif
 endfunction
 
+function! s:conflict_marker()
+  " Checks for git conflict markers
+  let annotation = '\%([0-9A-Za-z_.:]\+\)\?'
+  let pattern = '^\%(\%(<\{7} '.annotation. '\)\|\%(=\{7\}\)\|\%(>\{7\} '.annotation.'\)\)$'
+  let result = search(pattern, 'nw')
+  return result
+endfunction
+
 function! airline#extensions#whitespace#check()
   let max_lines = get(g:, 'airline#extensions#whitespace#max_lines', 20000)
   if &readonly || !&modifiable || !s:enabled || line('$') > max_lines
@@ -90,7 +98,12 @@ function! airline#extensions#whitespace#check()
       let long = search('\%>'.&tw.'v.\+', 'nw')
     endif
 
-    if trailing != 0 || mixed != 0 || long != 0 || !empty(mixed_file)
+    let conflicts = 0
+    if index(checks, 'conflicts') > -1
+      let conflicts = s:conflict_marker()
+    endif
+
+    if trailing != 0 || mixed != 0 || long != 0 || !empty(mixed_file) || conflicts != 0
       let b:airline_whitespace_check = s:symbol
       if strlen(s:symbol) > 0
         let space = (g:airline_symbols.space)
@@ -115,6 +128,10 @@ function! airline#extensions#whitespace#check()
           let mixed_indent_file_fmt = get(g:, 'airline#extensions#whitespace#mixed_indent_file_format', '[%s]mix-indent-file')
           let b:airline_whitespace_check .= space.printf(mixed_indent_file_fmt, mixed_file)
         endif
+        if !empty(conflicts)
+          let conflicts_fmt = get(g:, 'airline#extensions#whitespace#conflicts_format', '[%s]conflicts')
+          let b:airline_whitespace_check .= space.printf(conflicts_fmt, conflicts)
+        endif
       endif
     endif
   endif

doc/airline.txt

@@ -1145,10 +1145,11 @@ virtualenv <https://github.com/jmcantrell/vim-virtualenv>
   " long:   overlong lines
   " trailing: trailing whitespace
   " mixed-indent-file: different indentation in different lines
-  let g:airline#extensions#whitespace#checks = [ 'indent', 'trailing', 'long', 'mixed-indent-file' ]
+  " conflicts: checks for conflict markers
+  let g:airline#extensions#whitespace#checks = [ 'indent', 'trailing', 'long', 'mixed-indent-file', 'conflicts' ]
 
   " this can also be configured for an individual buffer
-  let b:airline_whitespace_checks = [ 'indent', 'trailing', 'long', 'mixed-indent-file' ]
+  let b:airline_whitespace_checks = [ 'indent', 'trailing', 'long', 'mixed-indent-file', 'conflicts ]
 <
 * configure the maximum number of lines where whitespace checking is enabled. >
   let g:airline#extensions#whitespace#max_lines = 20000
@@ -1161,6 +1162,7 @@ virtualenv <https://github.com/jmcantrell/vim-virtualenv>
   let g:airline#extensions#whitespace#mixed_indent_format = 'mixed-indent[%s]'
   let g:airline#extensions#whitespace#long_format = 'long[%s]'
   let g:airline#extensions#whitespace#mixed_indent_file_format = 'mix-indent-file[%s]'
+  let g:airline#extensions#whitespace#conflicts_format = 'conflicts[%s]'
 
 * configure custom trailing whitespace regexp rule >
   let g:airline#extensions#whitespace#trailing_regexp = '\s$'