From 1db371f776215ab0d1c49c9780e008a6d41d3faf Mon Sep 17 00:00:00 2001
From: Andrea Cedraro <a.cedraro@gmail.com>
Date: Thu, 19 Feb 2015 10:18:17 +0100
Subject: [PATCH] Do not guess settings if nomodifiable

---
 plugin/sleuth.vim | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/plugin/sleuth.vim b/plugin/sleuth.vim
index 94e36c8..8d57223 100644
--- a/plugin/sleuth.vim
+++ b/plugin/sleuth.vim
@@ -117,6 +117,10 @@ function! s:apply_if_ready(options) abort
 endfunction
 
 function! s:detect() abort
+  if &modifiable == 0
+    return
+  endif
+
   let options = s:guess(getline(1, 1024))
   if s:apply_if_ready(options)
     return